SOPAC - WordPress.com · [3] TABLE OF CONTENTS ACKNOWLEDGEMENTS 4 ACRONYMS 4 1 INTRODUCTION 5 2 SOURCES OF TSUNAMI HAZARD 6 3 VULNERABILITY /EXPOSURE 8 4 OVERVIEW OF TSUNAMI HAZARD

SOPACSOPAC /GA Tsunami Hazard Assessment Project

Report 04

Inventory of Geospatial Data and Options forTsunami Inundation & Risk Modelling

SOLOMON ISLANDS

Helen Pearce(helen@a sopac.org)

January 2008

[2]

Complied by

Helen Pearce

Ocean & Islands ProgrammeSOPAC Secretariat

This report may also be referred to as SOPAC Miscellaneous Report 654

Copies of this report may be obtained from:SOPAC Secretariat

Private Mail BagGPO, SuvaFiji Islands

Phone: (679) 3381377Fax: (679) 3370040

http: / /www.sopac.orgE -mail: [email protected]

[SOPAC Miscellaneous Report 654 - Pearce]

[3]

TABLE OF CONTENTS

ACKNOWLEDGEMENTS 4

ACRONYMS 4

1 INTRODUCTION 5

2 SOURCES OF TSUNAMI HAZARD 6

3 VULNERABILITY /EXPOSURE 8

4 OVERVIEW OF TSUNAMI HAZARD AFFECTING SW PACIFIC 10

(i) Summary Extracts. 10

(ii) Summary and Interpretation for Solomon Islands 14(a) Composite of Deep -water Tsunami generated by 8.5 Mw Sources around Pacific 14(b) Composite of Deep -water Tsunami generated by 9.0 Mw Sources around Pacific 15

5 Data Available at SOPAC for Inundation Modelling 16

(i) Bathymetry Datasets and Marine Charts 16

(ii) Satellite Imagery 26

NO Topography, Coastline and Reefs 26

(iv) Infrastructure data 27

(v) Post tsunami inundation /run -up data 27

(iv) Data Summary 30

6 SUMMARY 32

7 REFERENCES 33

APPENDIX 1: Datum and Definitions 35

1 Datum and Geodetic Levels at Honiara 35

2 Topographic Dataset Issues for PICs 36

3 Definitions and Acronyms 37

APPENDIX 2: Historical Tsunami Events Affecting Solomon Islands 44

1 Previous Tsunami that have been recorded in Solomon Islands 44

2 Recent PTWC Warnings 46

3 Tsunami Warning Related Background 59(í) Summary of JMA /PTWC causal earthquake criteria 59(ii) Tsunami hazard sources 60(iii) Real -Time Sea level data available for Tsunami monitoring 61

Appendix 3: Additional Modelling 64

1 Modelling of major tsunami for sources around the Pacific 64

2 MOST scenarios for sources affecting Solomon Islands 70


[4]

ACKNOWLEDGEMENTS

The assistance of Mary Power, Arthur Webb and Jens Kruger of SOPAC, Phil Cummins, ChrisThomas and Jane Sexton of Geoscience Australia, Ruth Broco of NGDC Tsunami Database andproject funding from AusAid is gratefully acknowledged.

ACRONYMS(Also see Appendix 1 -3)

ABoM Australian Bureau of MeteorologyATAS Australian Tsunami Alert Service (superseded by JATWC)CD Chart DatumDART Deep -ocean Assessment and Reporting of Tsunami.DEM Digital Elevation ModelDSM Digital Surface ModelEEZ Economic Exclusion ZoneGA Geoscience AustraliaGNS Geological and Nuclear Sciences, New ZealandGTS Global Telecommunications SystemHAT Highest Astronomical TideIOC Intergovernmental Oceanographic CommissionITIC International Tsunami Information CentreJMA Japan Meteorological AgencyJATWC Joint Australian Tsunami Warning CentreLIDAR Light Detection and RangingLAT Lowest Astronomical TideMOST Method of Splitting Tsunami ( type of numerical model)MSL Mean Sea LevelNGDC National Geophysical Data Centre (NOAA)PIC Pacific Islands CountriesPDC Pacific Disaster CentrePTWC Pacific Tsunami Warning CentreSOPAC Pacific Islands Applied Geoscience CommissionSPSLMP South Pacific Sea Level and Climate Monitoring ProjectUNESCO United Nations Environmental, Scientific and Cultural OrganisationUTC Universal Time Coordinate (also referred to by Z or GMT)UTM Universal Transverse MercatorWGS World Geodetic SystemWMO World Meteorological Organization


[5]

1 INTRODUCTION

SOPAC and Geoscience Australia, funded by AusAid have established the first component of amulti -stage project to look at tsunami hazard and risk assessment in the Southwest Pacific. As partof that project Geoscience have produced a tsunami hazard assessment for the Southwest Pacificbased on a deterministic deep -water tsunami propagation model (A Preliminary Study into theTsunami Hazard faced by Southwest Pacific, Thomas et al. 2007). That report is available at via thePacific Disaster Net ( http: / /www.pacificdisaster.net /drm /). In parallel with that component of theproject a review of data available for inundation modelling in SW Pacific is being conducted bySOPAC, as inundation modelling requires significantly higher -resolution bathymetry, inter -tidal andcoastal topography than the deep -water propagation models.

Deep -water models alone are not sufficient to develop a detailed understanding of tsunamiinundation on coastlines and ultimately it is proposed that the deepwater model output will be usedto define the boundary conditions to allow more detailed, site specific tsunami inundation modellingof key and priority PIC coastal areas. The combination of the deepwater propagation andinundation model out -put will then be used to provide information and tools for emergencymanagement and infrastructure planning in the SW Pacific. However, detailed tsunami inundationmodelling can only be undertaken if bathymetry (seafloor mapping) and topographic (land elevationor height) data of adequate quality and coverage exist.

SOPAC, through EU funded projects, has been addressing the some of the needs in the PacificRegion for high -resolution bathymetry data. This data is underpinning a number of critical technicalprojects in the areas of marine boundaries, fisheries, coastal processes, and in hydrodynamicmodelling for projects in support of reducing impacts of aggregate mining etc. However there isvery little in the way of high resolution coastal and inter -tidal topography data available in thePacific region that is suitable for inundation and sea -level change modelling and monitoring. Thereis a distinct possibility that the issue of inadequate topographic data in many Pacific IslandCountries (PICs) and the limiting effect this may have on tsunami and other inundation modellingmay require consideration of options to improve coastal topographic data collection by methodssuch as LIDAR.

This report for Solomon Islands is the fourth of a series of reports and reviews the availability ofhigh resolution inshore bathymetry and also inter -tidal and coastal topography of low lying coastalareas. The reports completed so far (Pearce, 2007a -c) are available through the Pacific DisasterNet and the SOPAC virtual library.

Geographical information and location of Solomon Islands are at Table 1 and Figure 1.

Table 1: Geographic Information for Solomon Islands( http: / /www.sopac.orq /tiki /tiki- index.php ?page = Solomon +Islands).

Capital: Honiara

Population: 409, 042 (1999)Land Area: 28, 785 sq. kilometresMax Height (above Sea -level): 2, 447 m (Mt. Makarakombou)EEZ: 1, 340, 000 sq. kilometres

Rainfall: Varies from 3,000 - 5,000 mm per annumMean Temperature: 26 °C

GDP per Capita: SB $584 (2002)Currency: Solomon Island Dollar (SB$)Languages: English (official), Pidgin and 87 other languagesGovernment: Independent State and Member of the CommonwealthSOPAC Membership: Joined in 1972 as full members of SOPAC (then CCOP /SOPAC)


[6]

PAPUANEW

\GUINEAChoiseut

GizoSanta fsabef

`Yandina Malaita

HON IARA ®GUOCISIrarr74ri ihOIL

Solomon SanCristobai

SouthPacificOcean

Coral Sea

0 150 300 km

ß 1$O 300 rni

SantaCruz

'stands

VANUATU

Figure 1: Location of Solomon Islands.

2 SOURCES OF TSUNAMI HAZARD

Major subduction zones are the predominant source of earthquakes large enough to generateregional or ocean -wide tsunami. They are the main focus of the preliminary hazard analysis report(Thomas et al. 2007) which models magnitude 8.5 and 9.0 earthquake source tsunami generation(as discussed in section 4). The location and names of these subduction zones are shown below inFigure 2. The Solomon Islands are located very close to a major source, the Solomons Trench.

Tsunami can also be generated from other processes such as meteors, volcanic eruption, volcaniccollapse and submarine landslide. The latter are often triggered by earthquakes and are commonlyattributed to the earthquake. Steep sloped bathymetry on volcanic and other islands andsubmarine volcanoes may have the potential to slump or collapse and depending of the size ofsuch collapses these events may cause local tsunami. The location of the 3 major volcanos,Kavachi, Savo and Tinakula are shown at Figure 3. Small tsunami were observed from Kavachi in1955 and from Tinakula in 1966 and 1971.

A table of the causal earthquake criteria for local, regional and ocean -wide tsunami (i.e. 100 km,1000 km, >1000 km) and the range of expected destructive impact, similar to that used for warningpurposes by the Japan Meteorological Agency (JMA), Pacific Tsunami Warning Centre (PTWC)and Australian Tsunami Alert Service (ATAS) is described in Appendix 2 Section (ii)Table A2 -3.The PTWC Bulletins are issued as advice to government agencies. Only national and localgovernment agencies have the authority to make decisions regarding the official state of alert intheir area and any actions to be taken in response.

There is a sea level recording site in Honiara since 1992, operated by the Australian Bureau ofMeteorology (ABoM). Recorded historical earthquake and volcanic generated tsunami eventsaffecting the Solomon Islands are discussed at Appendix 2, along with examples of PTWC bulletinsissued for the 2 April 2007 tsunami and the smaller Santa Cruz 2 September 2007 tsunami. Theperiod of records available is short compared to the recurrence interval of large events on theSolomons Trench. More work could be done to collect paleo- seismic and paleo- tsunami


[7]

information and oral history of tsunami in the region to assist with estimates of probabilities ofevents associated with that source.

Continental Rift - Oceanic Spreading- Continental Transform Oceanic Transform

Continental Convergent Oceanic Convergent- Subduction Zone

60`

40`

20`

o°

-20'

_40°

-60'120° 140° 160° 180° 200° 220° 240° 260° 280°Figure 2: Map of Major plate boundaries in Pacific Ocean with subduction zones labelled as follows: AIT-Aleutian Trench, ChT- Chile Trench CsT- Cascadia Trough, HT- Hikurangi Trough, IBT- Izu Bonin Trench,JpT- Japan Trench, KmT- Kermadec Trench, KrT- Kuril Trench, MT- Mariana Trench, MAT- Middle AmericaTrench, NT- Nankai Trench, NGT- New Guinea Trench, NHT- New Hebrides Trench, PhT- PhilippinesTrench, PTT- Peru Trench, PyT- Puysegur Trench, RT- Ryukyu Trench, SST- South Solomons Trench, TnT-Tonga Trench. Subduction Plate margins are shown in blue and are the source of the largest earthquakes inhistory (Thomas et al. 2007). Locations of Solomon Islands is marked in purple.

Major Volcanoes of Solomon Islands

APIA NEWSouthPacific

Kavachi Ocean

4 ` Savo5. SOLOMON ISLANDS

Honiara - -

SolomonSea

Cora! Sea

300 km

300 mi

Tinakula

VANUATU o,_

MUMS Topnka IJSGSICVO, 2G oo; Basem&p waffled fromCIA, 1999,' Volcanoes from Sirmkin&SieLert 1994

Figure 3: Major Volcanoes in Solomon Islands.


[8]

3 VULNERABILITY /EXPOSURE

The Solomon Islands are very close to Solomons Trench to the southwest and to the northern partof the New Hebrides Trench to the south. They are also vulnerable from the NW from the Mariana,Western Aleutian and Nankai Trench sources.

Any local, regional or ocean -wide event generated by the Solomons Trench would reach parts ofSolomons with minimal formal warning lead time, apart from feeling the earthquake. Any regionalor ocean -wide event from New Hebrides Trench and eastern PNG (still part of Solomons Trench)would reach parts of the Solomon Islands within 3 hrs. Any ocean wide event from the NW sourceswould have 4 -10 hrs lead time for a warning to be disseminated.

The major island or submarine volcanos are potential sources of local tsunami. One of these,Savo, is located only 35 km NNW Honiara, the capital city of the Solomon Islands, Honiara arelatively highly populated area. It would be potentially vulnerable to any landslide generatedtsunami from this source.

All the significant recorded tsunami run -up events in the Solomon Islands have been generatedfrom the Solomons Trench e.g. the recent 2 April 2007 event near Ghizo, Beaufort Bay on the westcoast of Gaudalcanal in 1939 and San Cristobal Island in 1931, Gaudalcanal in 1961 and Choiseul1974 (Table A2 -1).

The 2 April 2007 tsunami reached parts of the coast within 10 minutes of the earthquake (Figure4). This is insufficient lead time for formal warnings to be effective. Villagers very close to thesource of the earthquake need to rely on public education, feeling the earthquake and selfevacuation where appropriate. The further a region is from the source the more lead time isavailable to facilitate formal warning processes, e.g. the tsunami travel time to Honiara wasapproximately 40 minutes and to Kirakira on San Cristobal Island approximately 56 minutes.

400

600

E -800

-1000

-1200

-1400 i i i i r

-600 .100 200 0 200 400 600 800 1000

X [km]

Figure 4: Post tsunami modelling at 10 minutes after the 2 April 2007 earthquake, showing extremely shortlead time before the tsunami generated on the Solomons Trench reached populated areas of SolomonIslands. Red represents wave peak, blue the wave trough. (Tomita et al. 2007).


[9]

The prior knowledge of potential impacts from various sources, both close to and distant from theSolomon Islands, is therefore critical. With the deepwater modelling as input into island specific,finer resolution tsunami inundation models, a greater understanding of the potential risk andpossible impacts of tsunami may be realised. It will then be extremely important to communicatethe comparative risks and consequences within all hazard frameworks and action plans. It shouldbe noted however that accurate detailed tsunami inundation modelling can only be undertakenwhere adequate bathymetric (seafloor mapping) and topographic (land height or elevation)information exists.

Tsunami generating mechanisms are themselves not known to be impacted on by climate changedirectly. However, climate change may impact indirectly (Figure 5) by reducing the innate resilienceof coastal systems; e.g. increased sea -level, erosion, etc. and thereby, leave coastal communitiesin a position of greater vulnerability. A further example is the timing of impact with sea state andhigh tides; e.g. if a tsunami arrives during a spring low tide the impacts would be less than if itarrived during a spring high tide (Appendix 1 Section 3).

V .61.1.

N

C.J x

['nuaul hluurd rmarnc pnrrnr rnFlnrnred by elnn11e rhunge

Storms cyclones (winds pressure)

Sea level (Seasonal. ENSO. IPO)

Earth slides ! earthquakestect onic movements Tides

Tsunami Sea levelchange

Coastal inundation

1 1Storm tide CiuTents

AL IL

SST

SedimentWaves & movement &

swell supply

Coastal erosion 1111 11M1

Figure 5: Tsunami generation not directly influenced by climate change, however indirectly influencesimpact (Glassey et al. 2005).


[10]

4 OVERVIEW OF TSUNAMI HAZARD AFFECTING SW PACIFIC

A deterministic broad scale tsunami hazard assessment for the SW Pacific based on the deep -water tsunami propagation model was conducted (Thomas et al., 2007) by Geoscience Australiafocusing on the major subduction zone sources (Figure 2) around the Pacific. Section (i) belowcontains summary extracts from that report and section (ii) contains extracts specific to SolomonIslands and some added interpretation. Solomon Islands were ranked Category 5 (Suite 1) and 5(Suite 2) in the preliminary deep -water tsunami hazard study (these categories are explainedbelow).

(i) Summary Extracts:

"To aid in interpretation of the results, offshore tsunami amplitudes have been categorized into 5 ranges (Table1). Categories corresponding to a higher range of offshore tsunami amplitudes can presumably be associatedwith a higher level of hazard on coastlines of similar type. This categorization has been adopted throughout thisreport. It is important to note, however, that these ranges do not reflect the inundation that normally causesdamage and /or fatalities and which can often vary widely depending on local bathymetry and topography. Thecategories indicated in Table 1 are therefore best viewed as indicating a relative level of hazard over areas ofbroad geographic extent. For example, a Category 5 tsunami along the coast ofPapua New Guinea represents a higher level of hazard than a Category 2 tsunami along the coast of NewCaledonia.

It is premature, however, to interpret Table 1 in terms of impacts. This is especially true for low -lying atolls suchas Tuvalu and Kiribati. On the one hand, the lack of any high ground may appear to make these islandsespecially vulnerable to tsunami, so that even a Category 2 tsunami may be a cause for serious concern. On theother hand, because such atolls often have steep drop -offs in which ocean depths increase very rapidly withdistance from the fringing reef, there may not be a pronounced shoaling effect, so that these islandsmay never experience a large tsunami. Such considerations require much more modelling to address and arebeyond the scope of the present study, although it is intended that they be considered in a later phase of thisproject. In particular, the information presented in this report should not be used as a guide for responding totsunami warnings. The information presented here is preliminary and is only intended as a rough guide forprioritizing work in subsequent phases of this project.

Table 1: Categorisation of offshore tsunami amplitudes, normalised to equivalent depth of 50metres. The "Colour " columnrefers to the colour used for amplitudes of this category which have been used throughout this report

Cfltegory Narrna]ised Amplitude (em) I C.83our

I 0-2rr _M_2 25 - 75

8 75-150

4 150 - 250 ]

G > 250 II

Tsunami generated by two suites of simulated earthquakes were studied: Suite 1, consisted of 187 momentmagnitude (Mw) 8.5 earthquakes, and Suite 2 comprised 39 Mw 9.0 earthquakes (Figures 5 and 7, pages 11 and13). The results are summarised in Table 2. For both suites of earthquakes the nations most affected were in thesouth and west of the study area, including Vanuatu, Papua New Guinea, Guam, Solomon Islands and Tonga,each of which recorded Category 5 amplitude tsunami from the Suite 1 (Mw 8.5 earthquakes). This is due to theproximity of these countries to the subduction zones and the orientation of the fault lines which acts to direct thetsunami towards these nations "...

... Nations in the north and east of the study area, such as Kiribati, Marshall Islands, Nauru, Cook Islands,French Polynesia and Tuvalu were much less affected by the Suite 1 tsunami and only experienced Category 1 or2 sized waves. As is to be expected, Suite 2 events produced greater effects than those of Suite 1 on all nations.Notable in this respect is Fiji which experienced Category 5 amplitudes from Suite 2 events. However it should be


noted that without further investigation it is not possible to say that even Category 2 amplitudes will not producesignificant run -up at some locations.

The figures in Appendix A show that Suite 1 events (Mw = 8.5) from the subduction zones in the eastern and farnorthern rims of the Pacific did not produce effects larger than Category 2 on any of the nations studied. Howeversome Suite 2 events (Mw = 9.0) in the Peru - Chile, Aleutians and Kuril subduction zones did produce Category 3

or above effects for some nations

Table 2: Summary of results. Categories represent the highest amplitude recorded for that nation, and should be interpretedaccording to Table 1.

C attiFÿo rySuit 1 SUlt-E' 2:irnoeicari .Sauur a :! 3

Cook Lsl;ilydh ! t

Fiji :-0 5

French Poly i1iSl"zl } a

G u mu ,1 5

Kiribati 2 a

Mar 611 all I.-1;J ud.5 _' 3

VS. 4F Micronesia .1

N;-1l3ru 1 '?

Ncs. Cal C.r3anin .E 4

Mlle $ 4

Ps1 au 3 4

Piip118 New Gliilleil 5

5aln0ul -E 4

So loam L Islsnd5 5 .,

TorxE;e4 s 5

Tuvalu ? 1

VA> 1u:l t u G 5

....Events from Suite 1 in the subduction zones of the east, north and northwest rim of the Pacific have less effecton the region, either because of their distance, because the orientation of the fault lines acts to direct tsunamienergy away from the region, or because of intervening bathymetric features. They rarely produced normalisedamplitudes greater than Category 1, and never greater than Category 2.


[12]

Table 3: Most significant source regions for each nation, based on model out put points that recorded a maximum amplitudeexceeding 75 centimetres for Suite 1 (Mw 8.5).

Nation Maximum Am-plitude for allTide Gaugesfor all Mw 8.5Tsunami (cm)

Most Significant SourceRegions (amplitudegreater than 75cm at50m depth or single mostsignificant source regionif no amplitude exceeds75cm

American Samoa 92 TongaCook Lslands 44 TongaFiji 140 Tonga, Kermadec, New He-

bridesFrench Polynesia 50 TongaGuani 300 Mariana, 12u -BoninKiribati 49 PeruMarshall Islands 40 New HebridesF.S. of Micronesia 160 Marina, New Guinea, Philip-

pines. South SolomonsNauru 20 South SolomonsNew Caledonia 160 New Hebrides, South

SolomonNiue 110 TongaPalau 130 Philippines, New GuineaPapau New Guinea. 310 South Solomon, New Guinea,

MarianaSamoa 160 TongaSolomon Islands 290 South Solomons, New He-

bridesTonga 260 TongaTavahi 57 New HebridesVanuatu 380 New Hebrides, South

Solomon, Tonga, Kermadec

....This modelling pays no regard to the probability of events of various magnitudes occurring on any of thesesubduction zones. While there is no doubt that the Chile sub -duction zone can host an earthquake exceeding Mw9.0 (the 1960 event was magnitude 9.5) there is as yet no consensus on a reliable method of determining theabsolute maximum magnitude on any given subduction zone. We believe that most seismologists would agreethat a magnitude 8.5 event is plausible on any of the subduction zones considered here, and that a 9.0 event isimpossible to rule out. Hence we consider both magnitudes. A probabilistic tsunami hazard study would considera range of earthquake magnitudes and weight them according to estimates of their likelihood, in a similar way tothe method described in Burbidge et al, (2007).

....Like Suite 1, the nations most affected by the Suite 2 events were those in the south and west of the studyarea, as a result of the subduction zones in that region. However the plots in Appendix A show that Suite 2 eventsin the Chile -Peru, Cascadia, Aleutians and Kuril subduction zones produced significant (Category 3 or above)normalised amplitudes for some nations. For example the simulations indicate that the Chile -Peru zone is asignificant source of hazard from Mw 9.0 events for Fiji and French Polynesia, as are the Aleutian and Kurilsubduction zones for Guam, Federated States of Micronesia, Papua New Guinea, the Solomon Islands andVanuatu. Significant normalised amplitudes were produced in Papua New Guinea and the Solomon Islands frommodelled events in the Cascadia Subduction Zone.


[13]

Table 4: Most significant source regions for each nation, based on model out -put points that recorded a maximum amplitudeexceeding 75 centimetres for Suite 2 (Mw 9).

Nation Maximum Am-plitude for allTide Gaugesfor all Mw 9Tsunami (cm)

Most Significant Source Re-gions (amplitude greater than75cm at 50m depth or singlemost significant source region ifno amplitude exceeds 75cm )

American Samoa 140 TongaC, 3ok Islands 160 TongaFiji 390 Tonga, Kermadec, New Hebrides,

South Solomon, Aleutian, Peru,Chile

French Polynesia 120 Tonga. Kermadec, Peru, Chile.Aleutian

Guam 430 Mariana, Philippines. Ryukyu,Nankai, New Guinea, Aleutian,Izu -Bonin

Kiribati 99 PeruMarshall Islands 110 Kuril, MarianaMicronesia 230 Mariana, Philippines, New Guinea,

South Solomon. Aleuti:i.ns. Nankai,Ryukyu

Nauru 31 South SolomonsNew Caledonia 240 New Hebrides, South Solomon&

Tonga, KermadecNiue 210 TongaPalau 240 Philippines, Mariana, Ryukyu,

Nankai, New GuineaPapau New Guinea 340 South Solomon, Mariana, New

Guinea, Nankai, Ryukyu, Aleu-tians, Kuril, New Hebrides, Philip -lunes

Samoa 190 TongaSolomon Islands 310 South Solomon, New Hebrides,

Aleutians, Mariana, Ryukyu,Nankai

Tonga 330 Tonga, New Hebrides, KermadecTuvalu 88 New HebridesVanuatu 450 New Hebrides, Tonga, Aleutians,

South Solomons, Kermadec, Kuril,Nankai- Ryukyu


[14]

(ii) Summary and Interpretation for Solomon Islands

(a) Composite of Deep -water Tsunami generated by 8.5 Mw Sources around PacificBased on Figure 6 and 7 below, for an 8.5 Mw generated tsunami event, the Solomon IslandsTrench source has the potential to generate deep -water tsunami of Category 4 and 5 for parts ofthe Solomons. The Northern New Hebrides Trench has the potential to produce Category 3. TheNew Guinea, Southern New Hebrides, Mariana, and parts of Kuril, Western Aleutian, NorthernTonga and Kermadec Trenches have the potential to produce Category 2. Other more distantsources only have the potential is only for Category 1.120' 140" 160' 180' 200" 220 240` 260" 280' 300'

60

025 75 150 250cm

600

40

20'

0'

-20'

-40'

-60'

Figure 6: Composite of normalised source 8.5 Mw deep -water tsunami for Pacific. Maximum wave heightsfor the 187 tsunami of suite normalised to a standard depth of 50 m using Green's Law (Thomas et al. 2007).

Figure 7: Magnitude 8.5 earthquakes ranked by the Category of offshore tsunami they could cause atSolomon Islands. Each bar is displayed at the position of a magnitude 8.5 earthquake for which a tsunamiwas modelled, and the height and colour of the bar indicates the Category (Section 4 Table 1.) of theoffshore tsunami modelled in Solomon Islands (Thomas et al. 2007).


[15]

(b) Composite of Deep -water Tsunami generated by 9.0 Mw Sources around Pacific .

Based on Figure 8 and 9 below, for a 9 Mw generated tsunami event, the South Solomons Trenchsources have the potential to generate deep -water tsunami of Category 4 and 5 for parts ofSolomons. The New Hebrides to the south and Mariana, Western Aleutian, Nankai and Kuril,sources to the northwest, have the potential to generate category 3 for parts of Solomon Islands.Japan, Izu- Bonin, Philippines, Central Aleutian, Cascadia, Peru and parts of Chile trenches havethe potential to produce Category 2. The other sources have only the potential to generateCategory 1.

120 140 160 180` 200 220 240 260 280 300

0 25 75 150 250

3I cm:70

Figure 8: Composite of normalised source 9 Mw Tsunami for Pacific. Maximum wave heights for the 39tsunami normalised to a standard depth of 50 metres using Green's Law (Thomas et al. 2007)

co

U

U

'2o

Figure 9: Magnitude 9 earthquakes ranked by the Category of offshore tsunami they could cause atSolomon Islands. Each bar is displayed at the position of a magnitude 8.5 earthquake for which a tsunamiwas modelled, and the height and colour of the bar indicates the Category (Section 4 Table 1.) of theoffshore tsunami modelled in Solomon Islands (Thomas et al. 2007).


[16]

5 Data Available at SOPAC for Inundation Modelling

Global bathymetry and topography data sets were sufficient for the deep -water tsunami modellingused in the preliminary hazard assessment (Thomas et al. 2007). However inundation modelling,as does storm surge modelling, requires significantly higher resolution bathymetry as well as inter-tidal and coastal topography than the deep -water propagation models.

A review of the data available at SOPAC to support inundation modelling has been conducted.

(i) Bathymetry Datasets and Marine Charts

Global Deep Water Bathymetry

S2004 (Global 1 minute, -2km): Available via ftp fromftp: / /falcon.grdl.noaa.gov /pub /walter /Gebco SandS blend.bi2. S2004 merges the satellite altimeterdata derived Smith and Sandwell (1997) grid with GEBCO over shallow depths (Marks and Smith,2006).

Hydrographic Charts

A range of hydrographic charts at various scales are listed below with examples of coverage inFigures 10 -12.

avo

,

-._

SEALARK CHANNELAND

PROACHES in HONIARA

:-_ ---vtiar.ae,,...l i44 ,.ir

Figure 10: Sealark Channel and Approaches to Honiara: Datum Lat Mercator, WGS 72 1 :100,000 at Lat9 15S. Also shows the location of the volcano Savo approximately 35 km from Honiara.


[1 7]

Figure 11: Extract from Indispensable Strait 1:300,000 Mercator chart showing bathymetry of Guadalcanaland location of Beaufort Bay which had a recorded 10.5 m tsunami on 30 April 1939.

Figure 12: Extract of Ghizo Region from Choiseul Island to New Georgia Island (1979): Mercator, DatumLAT, WGS72, 1:300,000.

Approaches to Ghizo Harbour (1976) 1:25,000 Projection GnomonicDOS (1964) Datum: MHHW (not scanned)

Ghizo Harbour (1976) 1:12,500, Projection Gnomonic DOS (1964) Datum:MHHW (not scanned)


[18]

Fair -sheetsA range of additional bathymetry data is available from Australian Hydrographic Office (AHO)(Figures 13 -14) and the Solomon Islands Hydrographic Office (Figure 15) Fair Sheet holdings.Some of this data is in digital form and some is scanned hand drawn plots.

LegendGA Digital Holdings oIAHD RANs data

GA Digital Holdings of AHO dald

GA Digital Holdings 01 Swath dala

E-11 World - Polygons

I I

Figure 13: GA holdings of AHO Fair Sheet data.

0 100 200 400 1Glomele.s1 1, i+ 1 i 1 i I

Geoscience Australia Hydro Survey Holdings - Solomon Islands

.mw..,.,,.tl..a,Pod A Di wo.rc.wwar

dm.....-i.e.a.e

.wire

N

,"plfvlian [mp Mme

Auuralia

LmAr .r.cv

&wm`y

a... ©v,...r+,.-

Figure 14: More detailed view of AHO Fair Sheet holdings for area between Guadalcanal and Malaita.


[19]

[.1 11'/.[ 1 1 1:11{ Bi ll : li

11' i 9{I L]C H k5

.21-t "-.

1 '

¡¡`nn¡f. L%'

-- ` --Figure 15: Solomon Islands Hydrographic Office Fair Sheets for Ghizo area.

Other bathymetry Surveys

RV L'Atalante survey data using a Simrad EM12 multi -beam system, during the SOPACMAPSProject, Leg 2, 19 August to 16 September, 1993. Shown as contours without colour on Figure 18.

Single beam survey Marovo by University of Queensland (2005) shown in Figure 20.

SOPAC /EU SurveysSOPAC conducted bathymetry surveys in June and July 2005 covering Honiara, Marovo, Noro andGhizo. The locations are shown in Figure 16 and in more detail in Figure 17 and the bathymetrydata at Figures 18 to 22. The background to priority of the surveys for the various locations:

Ghizo: area which is relevant for aquaculture /pearl farming, tourism and marine protectedareas.Iron Bottom Sound (Honiara): Bathymetric survey to obtain physical oceanographic data inorder to generate management maps and hydrodynamic models to identify and managerisk of oil leakage from war relics and sewage outfall from HoniaraMarovo Lagoon: Generate management maps and hydrodynamic models to track dispersalof silt from deforestation on Vangunu. This area is a proposed World Heritage site importantfor tourism and fisheries.Noro: Survey to characterise pollution from fish cannery and provide baseline informationfor a hydrodynamics model.

Information on coverage area and maximum depth are at Table 2 and formats of data sets at Table2.

Table 2: Locations of SOPAC /EU bathymetry surveys


[20]

Location Area covered by MBES Maximum depth of coverageGhizo Up to 2 km off the barrier reef with

shallow water coverage inside thereef system.

500 m

Honiara 40 km offshore 1150 mMarovo 5 km inside the reef systems 500 mNoro 7.5 km off the eastern barrier reef 400 m

4°S

6°S

8°S

1o°S

12°S

14°S

16°S

_ i1111111"

Giz000 Márovo

\ Noro 0 Honiara

156°E 158°E 160°E 162 °E 164 °E 166°E 168°E 170 °E 172 °E

Figure 16: Solomon Islands EEZ showing locations of recent SOPAC /EU surveys.

ISABELVELLA LA VELLA

RANONGGA

SIMBO

GEORGIABUALA

DAI

MA

WESTERNVANGUNU

TE7EPARE---Kavachf

RUSSELL

0 50 100

kilometers

CENTR LFLORIDA

sxix<Q o

GUADALCANAL

Figure 17: Locations of recent SOPAC /EU bathymetry surveys in Western and Central Guadalcanal regions(Kruger, 2007).


[21]

Table 3: Formats for SOPAC /EU Bathymetry Survey data.

File type : DescriptionF' D F

TÌF h associatedMapinfo TAB file, andTFW world file.

Print ready AO -sized ohait of the multibeam bathymetry data atappropriate scales. Charts often include insets of shadedrelief, slope angle, and three dimensional perspective ima eg s.

Filled colour contours in raster TIFF format. Mapinfo users canuse the TAB file to open the contours as a backdrop image.Other GIS users can import the image with the referenceinformation contained in the TFW file and the projection statedon the PDF chart.

XYZ

GRD

Processed and comma delimited ASCII listing of X.Y,1 griddedsurvey points (Easting, Northing, Depth).Binary grid file of the points contained in the XYZ file in theGolden Software Suffer format. Many GIS packages acceptthis file for surface modelling.

There is reasonable bathymetry coverage around Ghizo and Honiara however there are gaps in theinshore shallow areas. Satellite derived bathymetry (from QuickBird or other satellites) could be anoption for filling in gaps in coverage. Satellite bathymetry usually is only viable for depths less than20 m. The timeframe and effectiveness of this option needs to be investigated further to establishviability and cost effectiveness.


[22]

I

f

.

i

1

=

ir

..,,- ._.

HALL

r-a Jr.% _

SOPAC

,,._...,.e.,..r.tA..pK6RMKw

Figure 18: SOPAC /EU Honiara Survey with previous 1993 survey contours shown without colour (Kruger & Kumar, 2007).

[SOPAC Miscellaneous Report 654- Pearce]

[23]

Figure 19: SOPAC /EU bathymetry for Ghizo (Kruger & Kumar 2007).


;PEN,

r

Meg.. pso1

b.nna

SOPAC

P,... ....w _blab

Ê.= cab, 1.0.1 PEER KNEW

0.

[24]

LIEMID

..,,.....

Oporognorpix .041a

S OFAS

10Ar-f............,

MP. . KNEW',e...... ..,....

Figure 20: SOPAC /EU bathymetry for Marovo (Kruger & Kumar, 2007).


[25]

almw aiN Non

Figure 21: SOPAC /EU bathymetry for Noro (Kruger & Kumar, 2007).


LENNO

ilm.................b......,. u....

CNAANNNAI

b

Iro

r. raw INN! NN ONN

Now WM ONLAAN 4NANNNANAo

M:

NOA,C,O ANCO on NOW..

MOOING INonadANCN

OAANna

r,74157,

nro

SQrpC

IMOIIANINNLTNI

oENRINA `PUP:.a.,. ANA OWN

[26]

(ii) Satellite Imagery

Landsat data is available for the Solomon Islands, 30m resolution.

SOPAC has also purchasing QuickBird pan sharpened (60cm resolution) data for:

Island Area (Km Sq)Vella Lavella 327Ranonga 262Ghizo 267Kolombangara 236Rendova 281

and IKONOS imagery for Ghizo, as the Quickbird image was of poor quality due to cloud cover.

(iii) Topography, Coastline and Reefs

(a) Topographic Maps are available at:1:50,000 (1968 -75) with 20m contours (including Honiara and Ghizo)1:10,000 with (1969- 1975)10m contours (datum MHWM 0.2m above MSL)1:2,500 (1969 -1975) Parts of Honiara township (datum MHWM 0.2m above MSL)

(b) Contours at 20 m intervals digitised from 50,000 topographic maps.

(c) Coastline defined as (MSL or MHWM) and reefs digitised from topographic maps andvarying resolution satellite imagery. Sources and metadata not available. This may needto be redone from Quickbird imagery.

(d) DEM /DSMSpace Shuttle Topography Mission 90m grid for all of Solomon Islands, WGS84,Geodetic, MSL. Data Directory: http://seamless.usqs.qov. This is far too coarse forinundation modelling requirements.

Digital Surface Model (DSM) with 5m vertical accuracy available in SolomonIslands. Specifications at Table 4 below.

The accuracy of the topography in the range MSL to 5m has a significant impact on the qualityand credibility of any tsunami inundation modelling. The Digital Surface Model represents thetops of trees and buildings rather than the ground as per a Digital Elevation Model (DEM) orDigital Terrain Model (DTM). The satellite DEM is very coarse and the suitability of the DSM forinundation modelling will be limited unless addition information is available to better define thelow lying topography in critical areas.

Table 4: Metadata for DSM


Solomon Islands Datasets

Totaling 27,000 sq. km., the Solomon Islands datasets are the result of

one of Intermap's countywide mapping projects. Our product offeringsindude elevation data and orthorectified radar imagery fORI). The

elevation data available is a digital surface model (DSM) of the first return

of the radar signal from free canopies. buildings, and other culturalfeatures. The ORI provides our users with an enhanced image mith a 1.25

mground resolution.

All datasets for the Solomon Islands are available for sale through theIntermap Store.

Solomon Islands Product Specifications

Vertical datum (geoid

model):

Horizontal (geodetic)

datum:

Projection:

File format (f3SM and DTM):

File format {ORI):

MOL as referenced to EGM9E

1.VGS84

UTM

32 -bit floating point binary grid format

(.bil)

8 -bit unsigned GeoTIFF format (.tif)

ORI Measures of Horizontal Accuracy (in)

Pixel Size RMSE

1.25 2.0

DSM Measures of Vertical Accuracy ( m)

Product Type Post Spadng RMSE

III 5 3.0

(iv) Infrastructure data

JI

[27]

Honiara was part of the Pacific Cities project in 1998. This project collected infrastructure in GISformat for a number of Pacific Cities. It would need some updating from satellite imagery. Ghizowas not part of Pacific cities project therefore infrastructure data is limited, however it could alsobe supplemented from satellite imagery.

(v) Post tsunami inundation /run -up data

The only international sea level monitoring gauge is in Honiara. Although it recorded thetsunami it was outside the main affected area. Post the 2 April 2007 Tsunami event a numberof international technical survey teams measured tsunami run -up, inundation and land levelchanges in the most affected areas. Figure 22 shows the survey points for the McAdoo team,Nishimura team and Tomita team surveys and are discussed in Kruger 2007. Figure 23 the run-up and inundation heights from the Tomita survey (Tomita et al. 2007). Figure 24 shows thelocations and heights for the Fritz team (Fritz & Kalligeris, 2008) survey:

These surveys results will provide and excellent opportunity to calibrate and verify anyinundation modelling undertaken for this region.


[28]

EX '"an.

anvnagaIsRland

Simhv

Solomon IslandsWestern Province

Area affected by the2 April 2907

Earthquake and Tsunami

Vella Lavella

9 IsIan b

I

Sovey Location Pointe

O McAdoo of al.

Nishimura ¡Atli.

Tornita of ai.

Kolomhangara

NJano Island

tQ.GhiroIslam,4c

Island

Makuti

°D. Island

NusaAghana '

0 5 10 20 30 40Km

Figure 22: Location of post 2 April tsunami event surveys for 3 teams, Mc Adoo et al, Nishimura et al andTomita et al.

AmaE

h-e bä§e'm'is--Solomon lsfandsrllef

2.9

II

Reo

m r _" 1ÆLLA i'.AVkdEA lStANDr_+ .iì4 '` }%

`{avArt -' .ò' .iá8

.'`..F . ..I

¡ 41 v l'f ' 't.i , .. i

W.Va. .ipvo,ki i 5.

$Addl_ r f

lSLAIYD

i5 locPE

f Potential Tsunami -Affected. -Areas :òñ 1:O7 kiiyaltOS AT.

--. _ rfi.,'. -n 1446L413AfIÂf;l1 F

'

s".: . --L:

, ,.

'4 lemxni

.. -.- _.+,

mt+

R

rapan44

inurlati.on' .

ti

Giao ..

,nektrboe/,.__V-Iaigalil

dlk+ltn[áf--- ,.

m Mal , ar4va2.71n.

A,A-r._ .-.

jap

3.7mT rlan

%s/hifalir4.4w359r .6m

; *LANA.: New Manra

me.ou

-O! Apfü zafo. 4n

z0,$ §, alar. { `-4 kifi -- .26,1$m

15

Figure 23: Post tsunami survey information on run -ups and inundation heights (metres) from 2 AprilTsunami in Solomon Islands (Tomita et al. 2007).


I..200

AustraliaLi-0° 15

e tsunami runuptsunami heightuplift/subsidence -

alb

. . .

-Sasamunga Ir(Choiseul)

Vella Lavella ¡le.

G h izo .

Ranongcga

Simbo. . Ren dova "

[29]

r

Simbo12

lo

8

2

-2

12 10 8 6 4 2 0 -2 156height [m]

157c

Figure 24: Post 2 April 2007 tsunami survey information (Fritz & Kalligeris, 2008). Measured tsunamirun -up (red) tsunami heights (blue) and land level changes (green).


[30]

(vi) Data Summary

Table 5: Summary of available data

Type Resolution Metadataavailable

Datum /Projection Format

BathymetryS2004 Global 1 minute,

-2kmYes WGS 84 /MSL ASCII grid, xyz

Deep -water MultibeamSurvey data

AHO Fair Sheets

RV L'Atalante 1993

HoniaraGhizoMarovoNoro

Grid created fromSurvey dataHoniaraGhizoMarovoNoro

ContoursMapinfo Backdrop

Various

various

50m contours

Various

100m20m20m50m

10m to 50m then50m intervals

Yes

yes

UTM 57S,WGS 84, /LAT

Mercator /UTM Zone 57S,WGS 72/ LAT

xyz

Contours only

Surfer .grd)

Mapinfo

Marine chartsHoniaraGhizo

1:300,000 & 1:2,5001:100,0001;25,000

Yes Mercator /UTM Zone 57S,WGS 72/ LAT

Paper /scannedPaper /scanned

Satellite derivedbathymetry

Could be option tofill in gaps

None yet

CoastlinesOutline Various No UTM Zone 57S, WGS 84,

MSL or LAT?MapinfoLines

Reefs Platform No UTM Zone 57S, WGS 84TopographyTopographic mapsAll Solomon's

Honiara

Digitised Contours

1: 50,000 (1968 -75)with 20m contours(including Honiaraand Ghizo)

1: 10000(1969 -1975)with 10m contours(datum MHWM 0.2mabove MSL)1:2500 (1969 -1975)Parts of Honiaratownship (datumMHWM 0.2m aboveMSL)

Contours Digitisedfrom maps.

No

UTM 57S, WGS 72, MSLPaper Chart

Mapinfo Lines

Spot values None


[31]

(All Solomon Islands)Satellite DEM

Digital Surface Model(DSM)

90m

5m (Expected tobecome available)

yes WGS 84,MSL

UTM, WGS 84, MSL

ImageryLandsat

QuickbirdVellalavalleKanongoGhizoKolombangaraRendova

30m

0.6m pansharpened

Yes

Yes

UTM 57S, WGS 84 Geo- referencedTIF (Mapinfo)

InfrastructureHoniara

RoadsWharfAirportBuildings

GhizoRoadsWharfAirportBuildings

Digitised from1:10000 and 1:2500and satellite imagery

Digitised from1:50,000 maps andsatellite imagery

Pacific Citiesproject CD

No

UTM 57S, WGS 84

UTM 57S, WGS 84

MapinfoLines /polygons

Tsunami Run -up DataGhizoRendovaSimboChoiseulVella Lavella

various yes WGS, MSL xyz


[32]

6 SUMMARY

There are three main issues that will influence the priorities for and ability to do tsunamiinundation modelling in Pacific:

Hazard Category from deep -water modellingVulnerability /ExposureAvailability of high resolution bathymetry, and inter -tidal and coastal topography data

The extracts from the National Geophysical Data Centre (NGDC), Tsunami Inundation in TableA2 -1, show that for the tsunami that have been recorded all the most significant recordedevents are from the Solomons Trench source with a few regional events from eastern PNG (stillattributed to Solomons Trench) and Vanuatu (New Hebrides Trench). There were two recordedevents from Russia, although the recorded run -ups for these are less than 1 m.

The Solomon Islands are ranked Category 5 for both the 8.5 Mw and 9 Mw Solomons Trenchsource in the preliminary tsunami hazard study based on deep -water modelling (Section 3 andFigures A3 -1 (31, 32, and 33)). Travel times to the Solomon Islands from this trench would bevery short, providing minimal opportunity for formal warning. Other parts of the Solomon Islandsare also vulnerable to Category 3 events from the NW (Figures A3 -1 (15, 16, 23, 25, and 26));however these would have longer lead times for the formal warning process. The SolomonIslands also have 3 major volcanos, Kavachi, Savo and Tinakula which are possible sources oflocal tsunami. Small tsunami were observed from Kavachi in 1955 and Tinakula in 1966 and1971

The bathymetry and topographic data sets available are not yet complete enough to be suitablefor tsunami inundation modelling. There are significant gaps that would need to be addressedwith lower resolution sources. There are two areas where data sets could be further developed.These are Ghizo in relation to the Solomons Trench tsunami source scenarios and Honiara inrelation to a Savo volcanic cone collapse tsunami scenario. The resolution and quality of thebathymetry data sets between the Solomons Trench source to the south of Guadalcanal andthe area around Honiara on the north, which has SOPAC /EU bathymetry data, limits the viabilityfor modelling that source for Honiara. Satellite derived bathymetry may be a cost effective wayof address gaps in the bathymetry for both Ghizo and near Savo and Honiara.

A bigger issue is the topographic and inter -tidal data. Unfortunately, the available contour mapsand the Digital Surface Model (DSM) do not provide adequate definition of low lying areas.LIDAR data (Appendix 1 Section 2) of the coastal and inter tidal area would be ideal, butextremely expensive. It is uncertain at this stage whether the DSM can be improved orsupplemented and this needs to be investigated further. The cost effectiveness of acquiringextra data or the effect of using poorer resolution data on the results of the modelling wouldneed serious consideration.

The use of deep -water modelling from various sources as input into island specific, finerresolution inundation modelling is important for understanding the possible impacts and forcommunicating the comparative risk and consequences within the all hazard framework andaction plans. However this is only possible where the data sets available can be improved to asufficient quality and resolution to make this viable.

The post 2 April tsunami surveys of the run -up and inundation in the Ghizo area provide acritical data set for calibration and validation of an inundation model for the Ghizo area.Geoscience Australia as part of the next stage of the Hazard Assessment project will be lookingat the options for improving the bathymetry and topographic datasets in order to take advantageof the opportunity to use the post event data to further validate the inundation model results.


[33]

7 REFERENCES

ABoM, 2007. Australian Bureau of Meteorology Web Site. http: / /www.bom.gov.au

Biukoto, L., Swamy, M., Shorten, G. G., Schmall, S., and Teakle, G. 2001. Pacific Cities CD,Honiara. GIS Hazards Dataset, Version 1.1. SOPAC Data Release

Burbidge, D., Cummins, P. and Mleczko, R. 2007. A Probablistic Tsunami HazardAssessment for Western Australia. Report to the Fire and Emergency Services Authority ofWestern Australia, Geoscience Australia.

Cummins, P. 2007. The Solomon Islands Earthquake and Tsunami. Risk Research Group,Geoscience Australia.

Everingham, I. B. 1977. Preliminary catalogue of tsunami for the New Guinea / SolomonIslands region 1768 -1972, Dept of National Resources.

Glassey, P., Heron, D., Ramsey, D., & Salinger, J. 2005. Identifying Natural Hazards and therisk they pose to Tonga. GeosourceTonga, Study Report 4.

Fritz, H.M., & Kalligeris, N. (2008). Ancestral heritage saves tribes during 1 April2007Solomon Islands tsunami, Geophys. Res. Lett., 35, L01607, doi:10.1029/2007GL031654.

Howorth, R., Elaise, A. 1997. Workshop on Volcanic Hazards and Emergency Managementin the South Pacific. SOPAC Miscellaneous Report 245.

IAVCEI Workshop on Ulawun Decade Volcano, PNG. Volcanic Cone Collapses andTsunami: Issues for Emergency Management in the Southwest Pacific Region. GeologicalSurvey of Papua New Guinea and Australian Geological Survey Organisation, 1998.

Kruger, J. 2005. SOPAC /EU EDF8 Marine Survey Plan for Solomon Islands. SOPACReport.

Kruger, J., & Kumar, S., 2007. (in prep) Bathymetry of Solomon Islands. EU -SOPAC Report.

Kruger, J., 2007. Solomon Islands: Geological Impacts of 2 April 2007 earthquake andtsunami on the islands and marine environment of the Western Provinces. SOPACCountry Mission and technical Advisory Report.

Marks, K.M., & Smith W. H. F. 2006. An evaluation of publicly available global bathymetrygrids. Marine Geophysical Researches.

NGCD, 2007, NOAA /WDC Historical Tsunami Databasehttp: / /www.ngdc.noaa.gov /seg /hazard /tsu db.shtml

PDC. 2005. Tsunami Awareness Kit (Solomon Islands)http://www.pdc.orq/PDCNewsWebArticles/2005TAK/index.html

Pearce, H., 2006. ATAS /AusTWC Decision Processes, NMOC, ABoM.

Pearce, H., 2007. (a) Inventory of Available Geospatial Data and Options for TsunamiInundation & Risk Modelling, Tonga. SOPAC Miscellaneous Report MR651.

Pearce, H., 2007. (b) Inventory of Available Geospatial Data and Options for TsunamiInundation & Risk Modelling, Niue. SOPAC Miscellaneous Report MR652.


[34]

Pearce, H., 2007. (c) Inventory of Geospatial Data and Options for Tsunami Inundation &Risk Modelling, Kiribati. SOPAC Miscellaneous Report MR653.

Pearce, H., 2008. Inventory of Geospatial Data and Options for Tsunami Inundation &Risk Modelling, Fiji Islands. SOPAC Miscellaneous Report MR655.

Pugh, D. 2004. Changing Sea Levels, Effects of Tides, Weather and Climate.

Smith, W. & Sandwell, D., 1997. Global seafloor topography from satellite altimetry and shipdepth soundings, Science, v. 277, p. 1957 -1962, 26 Sept., 1997.

SPSLCMP Pacific Country Report, June 2005. Sea Level & Climate: Their Present StateSolomon Islands.

SPSLCMP Strategic Review Report (in prep. June 2007) South Pacific Sea level & ClimateMonitoring Project, Phase IV.

Thomas, C., Burbidge, D., & Cummins, P. 2007. A Preliminary Study into the TsunamiHazard faced by Southwest Pacific Nations, Risk and Impact Analysis Group, GeoscienceAustralia

Tomita, T., Arikawa, T., Tatasumi, D., Honda, K., Higashino, H, Watanabe, K, and Takahashi,S., 2007 (in prep) Preliminary Report on Field Survey of Solomon Islands Earthquake inApril 2007.

UNESCO ITIC, 2006. Tsunami Glossary http: / /ioc3.unesco.orq /itic /files /tsunami glossary.pdf

USGS 2007. United Stated Geological Survey web site, http: / /earthquake.usgs.gov/

Warne, J., 2007. Australian Tsunami Warning System Sea Level Observation System,ASLOS Network Design, Australian Bureau of Meteorology, (ABoM).

Wikipedia 2007. Tides, http: / /en.wikipedia.orq /wiki /Tide


[35]

APPENDIX 1

Datum and Definitions

1 Datum and Geodetic Levels at Honiara, Solomon Islands

Tuarugnú Sau."spue

SANJORGE

SANTASABEL

pU'a Sep° VikenaraPoint

H,ANH,ANAVISI

KO EM, IJ 'GAll

MANABA ISLANDMaluú 'Kwaillbesi

teGwaun ate.

Gape Ritters -Ma nu'Oala

Flu Bay esIwa e

AukIA Mount Kolovrat

FLORIDA lndÍspensable Bina

ISLANDS oLEVUGA Strait u FendndiPoint-"""'---NGGELASIJLE Siota

MALAITA'AIO

Petupetu° KusiniMOELAMII ° Tulagn NGGELAPILE porn,.

Baunan°M E KokamaN E S I A MBl1NGANA ISLAND qbungañ

Mbahl SealarN Channel ..,,,,rWho Point'Tambooe Sura'-ró

Lam. SEAFFIAME '

1#Tambunimane

Taro By Honiara Kaió ° RUA SURAova1.40.-EP0.1.40.-EP

ISLANDS

Lambungasi MereDALCANAL Kaoka BayBy74 Velasi°

BEAGLEf Ra uremb0 Poposá ISAND

yaw Nano `w&iere

SANDS Pomi ° aramakuru

g

Mount Pop

visu Pam,,

Solomon Sea

1.° 160 °30' 161°10°

Solomon Lskearch 1999

FBM 1

Datum ReferenceOn metres)

FBM 4 (FIXED HEIGHT)

SSBM

MEAN SEA LEVEL

TIDE STAFF ZERO

7.0761

4.3102

4.2647

0.6905

a.:aDOo

Figure Al -1: Datum for Honiara, Solomon Islands (SLCMP Country Report, 2005).

Mean Sea Level (MSL) in Figure Al -1 is the average recorded level over an extended period oftime. MSL at Honiara is 0.6905 metres above the SEAFRAME datum (LAT).


[36]

2 Topographic Dataset Issues for PICs

SOPAC is the regional agency with the technical capacity and tools to collect high qualitybathymetric data and also supports PICs in the collection of spot land elevation data. However,SOPAC does not have the tools to support rapid collection of topographic information overbroad scale areas. Such work is increasingly being undertaken remotely using tools which canmeasure large areas accurately and quickly, such as aircraft mounted LIDAR (Light Detectionand Ranging - a remote sensing system used to collect topographic data over large areasquickly and accurately). There is a distinct possibility that the issue of inadequate topographicdata in many PICs and the limiting effect this may have on tsunami inundation modelling mayrequire consideration of such approaches to topographic data collection.

Twin Engine Aircraft

Aircraft Elevation700 meiern)

Overlapping Swaths

310. degreeScan Angle

Scan WidthS- 30.13 meters!

Flight Direclion(paralidtoYtO.0erYj

Figure Al -2: Schematic of an aircraft mounted LIDAR system. Such systems are potentially capable ofsurveying shallow sub -tidal waters (too shallow for ship born bathymetry), intertidal zones, andtopography ( www.csc.noaa.gov /products.htm).


3 Definitions and Acronyms

Permanent Mark or Ewen mark (P.M) or(B.M.)

[37]

Highest Astronomical Tide (HAT.)

Australian Height Datum(A.H.D.i

Mean Higher High Water (M.H.H.W.)

Mean Lower High Water (M.L.H.W)

Wan Sea Level (M.S.L.)

Mean Higher Low Water (WHIM.)

Mear Lower Low Water (M.L,L,W,)_

, Datum of Predictions Port Datum Lowest Astronomical Tide (L.A.T.)

Figure Al -3: Datum

HAT (highest astronomical tide) LAT (lowest astronomical tide)These are the highest and lowest levels which can be predicted to occur under averageMHHW (mean higher high water) The height of MHHW is the mean of the higher of thetwo daily high waters over a long period of time. When only one high water occurs on aday, this is taken as the higher high water.

Meteorological effects on tidesMeteorological conditions which differ from the average will cause correspondingdifferences between the predicted and the actual tide. Variations in tidal heights aremainly caused by strong or prolonged winds and by unusually high or low barometricpressure.

Tidal predictions are computed for average barometric pressure. Low pressure systemstend to raise sea -levels and high pressure systems tend to lower them. The water doesnot, however, adjust itself immediately to a change of pressure. It responds, rather, tothe average change in pressure over a considerable area.

The effect of wind on sea -level and therefore on tidal heights and times is variable anddepends on the topography of the area in question. In general, it can be said that windwill raise the sea -level in the direction towards which it is blowing. A strong wind blowingstraight onshore will "pile up" the water and cause high waters to be higher thanpredicted, while winds blowing off the land will have the reverse effect.

MSL (mean sea level)The average level of the sea over a long period or the average level which would exist inthe absence of tides.

Storm surge (http: / /en.wikipedia.orq /wiki /Storm surge)A storm surge is an offshore rise of water associated with a low pressure weather system,typically a tropical cyclone. Storm surge is caused primarily by high winds pushing on theocean's surface. The wind causes the water to pile up higher than the ordinary sea level.Low pressure at the center of a weather system also has a small secondary effect, as canthe bathymetry of the body of water. It is this combined effect of low pressure and


[38]

persistent wind over a shallow water body which is the most common cause of stormsurge flooding problems. The term "storm surge" in casual (non- scientific) use is stormtide; that is, it refers to the rise of water associated with the storm, plus tide, wave run -up,and freshwater flooding. When referencing storm surge height, it is important to clarify theusage, as well as the reference point. NHC tropical storm reports reference storm surgeas water height above normal astronomical tide level, and storm tide as water heightabove mean sea level.

In areas where there is a significant difference between low tide and high tide, stormsurges are particularly damaging when they occur at the time of a high tide. In thesecases, this increases the difficulty of predicting the magnitude of a storm surge since itrequires weather forecasts to be accurate to within a few hours. The most extreme stormsurge events occur as a result of extreme weather systems, such as tropical cyclones.Factors that determine the surge heights for landfalling tropical cyclones include thespeed, intensity, size of the radius of maximum winds (RMW), radius of the wind fields,angle of the track relative to the coastline, the physical characteristics of the coastline andthe bathymetry of the water offshore.

tT n, Storm tideSurge ,s f

2n. Normal high tide

Mean sea level

Figure Al -4: Storm surge ( http: / /en. wikipedia.org /wiki /Storm_surge)

Sieches (Pugh 2004)Tide gauge records, particularly those from islands and places linked to oceans by narrowcontinental shelfs, often show high- frequency oscillations superimposed on the normaltidal changes of sea -level. These oscillations, called seiches, are due to local resonantoscillations of the harbours and coastal areas. The period depends on the horizontaldimensions and depth of water in the harbour. There are a number of triggers for seichingsuch as gravity waves, winds, atmospheric pressure disturbances and seismic activity.When the energy for sieching comes from external wave sources e.g. a tsunami, the sizeof the entrance to an oscillating basin is critical.

Shoaling

As a tsunami leaves the deep water of the open -ocean and travels into the shallowerwater near the coast, it transforms. A tsunami travels at a speed that is related to thewater depth - hence, as the water depth decreases, the tsunami slows. The tsunami'senergy flux, which is dependent on both its wave speed and wave height, remains nearlyconstant. Consequently, as the tsunami's speed diminishes, its height grows. This iscalled shoaling. Because of this shoaling effect, a tsunami that is unnoticeable at sea,may grow to be several metres or more in height near the coast.

The increase of the tsunami's wave height as it enters shallow water is given by:

where hs and hd are wave heights in shallow and deep water and HS and Ha are thedepths of the shallow and deep water. So a tsunami with a height of 1 m in the openocean where the water depth is 4000m would have a wave height of 4 to 5 m in water ofdepth 10 m.


[39]

Just like other water waves, tsunami begin to lose energy as they rush onshore - part ofthe wave energy is reflected offshore [and in the case of an atoll, around the island], whilethe shoreward -propagating wave energy is dissipated through bottom friction andturbulence. Despite these losses, tsunami can still reach the coast with tremendousamounts of energy. Depending on whether the first part of the tsunami to reach the shoreis a crest or a trough, it may appear as a rapidly rising or falling tide. Local bathymetrymay also cause the tsunami to appear as a series of breaking waves.

Tsunami

A tsunami is a series of ocean waves with very long wave lengths (typically hundreds ofkilometres) caused by large -scale disturbances of the ocean, such as:

earthquakes

landslide

volcanic eruptions

explosions

meteorites

These disturbances can either be from below (e.g. underwater earthquakes with largevertical displacements, submarine landslides) or from above (e.g. meteorite impacts).

Tsunami is a Japanese word with the English translation: "harbour wave ". In the past,tsunami have been referred to as "tidal waves" or "seismic sea waves ". The term "tidalwave" is misleading; even though a tsunami's impact upon a coastline is dependent uponthe tidal level at the time a tsunami strikes, tsunami are unrelated to the tides. (Tidesresult from the gravitational influences of the moon, sun, and planets.) The term "seismicsea wave" is also misleading. "Seismic" implies an earthquake -related generationmechanism, but a tsunami can also be caused by a non -seismic event, such as alandslide or meteorite impact.

Tsunami are also often confused with storm surges, even though they are quite differentphenomena. A storm surge is a rapid rise in coastal sea -level caused by a significantmeteorological event - these are often associated with tropical cyclones.

Tsunami Travel TimesTsunami can have wavelengths ranging from 10 to 500 km and wave periods of up to anhour. As a result of their long wavelengths, tsunami act as shallow -water waves. A wavebecomes a shallow -water wave when the wavelength is very large compared to the waterdepth. Shallow -water waves move at a speed, c, that is dependent upon the water depthand is given by the formula:

where g is the acceleration due to gravity (= 9.8 m /s2) and H is the depth of water (m).

As the travel times are dependant on depth of the water [H] rather than magnitude of theearthquake, scenario based travel times to any location can be pre- computed for anyearthquake tsunami source.

In the deep ocean, the typical water depth is around 4000 m, so a tsunami will thereforetravel at around 200 m /s, or more than 700 km /hr.

For tsunami that are generated by underwater earthquakes, the amplitude (i.e.waveheight) of the tsunami is determined by the amount by which the sea -floor is displaced.


[40]

Similarly, the wavelength and period of the tsunami are determined by the size and shapeof the underwater disturbance.

As well as traveling at high speeds, tsunami can also travel large distances with limitedenergy losses. As the tsunami propagates across the ocean, the wave crests canundergo refraction (bending), which is caused by segments of the wave moving atdifferent speeds as the water depth along the wave crest varies.

Types of waves (http: / /amath.colorado.edu /courses /4380 /All /ii43.pdf)There are a number of types of wave with a range of causes, physical mechanisms,periods, velocity and regions of influence affecting the oceans affecting the oceans andtherefore the tide gauge. These are shown in Table Al -1.

Al -1: A number of wave types that can be found in lakes and oceans.

Wave type Cause Physical mechanism Period Velocity Region influenced

Sound Sea life, ships Compressibility 10 -' - 10-' s 1.52 km/s Interior

Capillary ripples Wind Surface tension < 10 -' s 25 -50 cm/s Surface

Wind waves and Wind Gravity 1 -25 s 2 -40 ni's Surfaceswell

Sieches Earthquakes, Gravity. resonance minutes to standing waves Interior and surface ofstorms hours large lakes

Storm surges Low pressure Gravity and earth rotation 1 - 10 h -100 uils Coastalareas

Tsunami Earthquakes, Gravity 10 min - 2 h < 800 kinlh Interior; on surface atslides shores

Internal waves Stratification Gravity and density 2 min - 10 h < 5 mÌs Layer of sharp densityinstabilities, tides stratifications change

Tides Moon and sun External gravity fields 12 - 24 h 1700 hull: h: Interior; on surface atbores a few km/h shores (bores)

PIanetary waves Earth rotation Gravity - 100 days 1 -10 knn.'h Interior

Tidal heightsThe height of the tide, in metres, is reckoned from the port datum (lowest astronomicaltide (LAT) datum).

Tidal range variation: springs and neaps (http: / /en.wikipedia.org /wiki /Tide)

The semidiurnal tidal range (the difference in height between high and low tides overabout a half day) varies in a two -week or fortnightly cycle. Around new and full moonwhen the Sun, Moon and Earth form a line the tidal forces due to the Sun reinforce thoseof the Moon. The tide's range is then maximum: this is called the spring tide, or justsprings and is derived not from the season of spring but rather from the verb meaning "tojump" or "to leap up ". When the Moon is at first quarter or third quarter, the Sun and Moonare separated by 90 °when viewed from the earth, and the forces due to the Sun partiallycancel those of the Moon. At these points in the lunar cycle, the tide's range is minimum:this is called the neap tide, or neaps. Spring tides result in high waters that are higherthan average, low waters that are lower than average, slack water time that is shorterthan average and stronger tidal currents than average. Neaps result in less extreme tidalconditions. There is about a seven day interval between springs and neaps.

The changing distance of the Moon from the Earth also affects tide heights. When theMoon is at perigee the range is increased and when it is at apogee the range is reduced.Every 71/2 lunations, perigee coincides with either a new or full moon causing perigeantides with the largest tidal range. If a storm [or tsunami] happens to be moving onshore atthis time, the consequences (in the form of property damage, etc.) can be especiallysevere.


[41]

Tsunami run -up (http: / /walrus.wr.usgs.gov /tsunami /basics.html).As the tsunami wave travels from the deepwater, continental slope region to the near -shore region, tsunami run -up occurs. Run -up is a measurement of the height of the wateronshore observed above a reference sea level. Contrary to many artistic images oftsunami, most tsunami do not result in giant breaking waves (like normal surf waves at thebeach that curl over as they approach shore). Rather, they come in much like very strongand very fast tides (i.e., a rapid, local rise in sea level). Much of the damage inflicted bytsunami is caused by strong currents and floating debris. The small number of tsunamithat do break often form vertical walls of turbulent water called bores. Tsunami will oftentravel much farther inland than normal waves.

At a gauge reference sea level is the predicted tide height. Without a gauge it is often theMHW mark or MSL.

Inundation height

Sea level atthe event

Tsunami trace

Runupheight

Figure Al -5: Definitions of inundation and run -up height (Tornita et al. 2007).

Volcanic sources of tsunamiTsunami can be generated from other processes such as volcanic eruption, volcaniccollapse and submarine landslide. The latter are often triggered by earthquakes and arecommonly attributed to the earthquake. Steep sloped bathymetry on volcanic and otherislands and submarine volcanoes may have the potential to slump or collapse anddepending of the size of such collapses these events may cause local tsunami if debris isdumped into the sea.

1. Original summitof volcano

2. Volcano collapses

4. Lateral blast

3. Magma body is unroofed

5. Fast-movingdebris avalanchecrashes into sea/ 6. Tsunami forms

5

7. Wave travels outto distant coastlines

24,09!418Figure Al -6: Tsunami generation process from a volcanic collapse (IAVCEI Workshop on UlawunDecade Volcano, 1998).


[42]

Avalanche amphitheatre

Debris avalanche deposit

Rt `,O9Iib

ct ¡f, f 2b

Figure Al -7: Where debris collapses from an existing avalanche amphitheatre into the sea, it cangenerate a local tsunami (IAVCEI Workshop on Ulawun Decade Volcano, 1998).

Wave lengthThe mean horizontal distance between successive crests (or troughs) of a wave pattern.

Wave periodThe average time interval between passages of successive crests (or troughs) of waves.

Wave heightGenerally taken as the height difference between the wave crest and the precedingtrough.

Wave amplitude

Generally taken as the height above mean of wave, approximately half wave height.


[43]

Further information on tsunami

More information can be found at the following web sites:

General informationInternational Tsunami Information CenterWelcome to tsunami!Tsunami database (U.S. National Geophysical Data Center [NGDC])

Tsunami warning centres and hazard mitigationInternational Coordination Group for the Tsunami Warning System in the PacificPacific Tsunami Warning CenterWest Coast and Alaska Tsunami Warning CenterU.S. National Tsunami Hazard Mitigation Program

Earthquake informationGeoscience AustraliaU.S. National Earthquake Information CentreEuropean- Mediterranean Seismological Centre

The Indian Ocean tsunami of Dec. 26th 2004Scientific Background (from Columbia University)

Tsunami researchTsunami Research Center (University of Southern California)Tsunami Research Program (Pacific Marine Environmental Laboratory)


a.

[44]

APPENDIX 2

Historical Tsunami Events Affecting Solomon Islands

Previous Tsunami that have been recorded in Solomon Islands

Extracts from National Geophysical Data Centre (NGDC), Tsunami Inundation Database showthe highest recorded tsunami events in the Solomon Islands were: 10.5m at Beaufort Bay, onsouth west coast of Guadalcanal in 1939, 10m at Ghizo in 2007 and 9m at San Cristobal Islandin 1931. These were all from near by Solomons Trench sources. One event was recorded froma regional source in Vanuatu on the New Hebrides Trench in 2007. There are very fewrecorded run -ups from distant (ocean -wide) sources. Those recorded were from Russia in 1952and 2006 with both less than lm.

Table A2 -1 (a) & (b): Extracts from National Geophysical Data Centre (NGDC), Tsunami InundationDatabase (a) Source generating run -up event (b) location of run -up.

(a)Tsunami Events where Runup Country = SOLOMON ISLANDS

View parameter descriptions and access statistical information by clicking on column headings.

For additional information about the tsunami, runups, associated earthquake or volcanic eruption, click on the links in the Addl Info, Num. of Runups, Earthquake Mag,or Volcans

TsunamiDate

Year Mo Liv Fir Mn Sec Val Code Latitude Longitude

Cause

Earth -Quake Man

Tsunami Source LocationVal-caio Addi Tsu Info Country Name

1857 4 17 4 4 8.0 PAPUA NEW GUINEA (BISMARCK SEA -5.500 147.0001906 9 14 16 4 18,0 4 1 8_4 PAPUA NEW GUINEA [SOLOMON SEA I -7.000.1 149.0001931 10 3.19 13 13,0 4 1 7_9 e ISOLOMON ISLANDS ;SAN CRISTOBAL ISLAND I -20.506r 61.7501939 1 30 2 18 27,0 3 1 7.8 IPAPUA NEW GUINEA IBOUGAENVILLE ISLAND I -co6.S 155.5001939 4 30 2 55 30.0. 3 1 8_1 ISOLOMON ISLANDS SOLOMON ISLANDS

...

l0.500 I58.500I52.7501952. 11 4 15 58

1

41

1_ 9_0 IfìUSSLA KAMCNATKA 159.5001955 9 8 3 271 16.01 3 I i 6_5 IPAPUA NEW GUINEA ;SOLOMON SEA -6.900 155.7001957 11 [SOLOMON ISLANDS ISOLOMON ISLANDS

1959 B 17 21 41 40.01 7_3 ISOLOMON ISLANDS SOLOMON ISLANDS -7.500 156.0001961; 3 18 1 2 I 0 ISOLOMON ISLANDS ISOLOMON ISLANDS19511-81 1 5 39 53.21 6_6 ISOLOMON ISLANDS [SOLOMON SEA -9.900 166.5901966 15' 0. 7.6 [SOLOMON ISLANDS ISOLOMON ISLANDS -18.308 168:880

. 1966171' 28 1 1 O ISOLOMON ISLANDS IMOHAWK SAY, SANTA CRUZ ISLANDS 116.000 168.000I

1966r12'31'18123. 3.914 I 1 7.5 SOLOMON ISLANDS SAIVFA CRUZ ISLANDS -11.800 166.500196172: 31'22 ls. 14.0 1! I 1 7_3 [SOLOMON ISLANDS ;SANTA CRUZ ISLANDS -11.30U 164.880

I 1971! 7 14 51.1.! 29.1' 4 1 7.4 IPAPUA NEW GUINEA 'BISMARCK. SEA -5.500 153.9001971 7 25 1 23 21.3 4 1 7 -9 'PAPUA NEW GUINEA BISMARCK SEA -ß.900 153.206

11971; 9 6 20 4 Val SOLOMON ISLANDS 1TENAKULA, SANTA CRUZ -10.380 165.800

1

1972170. 9 4 I Vol IPAPUA NEW GUINEA ;RITTER ISLAND, PAPUA NEW GUINEA -5.520 148.1211974r-1 31 23 5.3 4 1 7_o [SOLOMON ISLANDS ISOLOMON ISLANDS -7.500 155.9651974[-2 I 37.2 33.11 4- 1 7.1 ;SOLOMON ISLANDS SOLOMON ISLANDS - 7.400 155.600

7977741 20123r131 10.41 4 I 1 6_8 ISOLOMON ISLANDS ISOLOMON ISLANDS -9.828 163.3231477r 4 0-1t21 50.5 I 1 7_6 ISOLOMON ISLANDS ISOLOMON ISLANDS -9.890 160.3481987 15.11 1 6.0 [SOLOMON ISLANDS iSOLOMON ISLANDS -10.707 162.325

1 I988r 701711 38 26.Y 1 7.6 ISOLOMON ISLANDS SOLOMON ISLANDS 0.366 160.81979911-21-9 1.8 58.317E! I 1 7.0 So LOMON ISLANDS SOLOMON ISLANDS 9.929. 159.1391991 f0 15 5112.71! I 1 7_3 [SOLOMON ISLANDS SOLOMON ISLANDS -9.098 158.440

1 19921 5 2711 131 38.81.' 1 7.1 [SOLOMON ISLANDS SANTA CRUZ ISLANDS -11.122 165.2391997r 41.21- 26.4..4 1 7.7 ISOLOMON ISLANDS SANTA CRUZ I8. VANUATU -12.584 I66.6762800 1.7!7541567 4 1 8.0 IPAPUA NEW GUINEA NEW IRELAND -3.988 I52.1692003 0IL17,13' 6.0 4 1 7.3 ISOLOMON ISLANDS SOLOMON ISLANDS -10.491 160.7792006 E1 I11-14. 13.5 4 1 8.3 [RUSS A S. KURIL ISLANDS 46.592 153.2662i1307151-01-401 1.6 4 1 7 -1 VANUA U ¡VANUATU ISLANDS - 29.517 169.357

1 20071 4 0 9:16.3 4 1 8.1 SOLOMON ISLANDS ISOLOMON ISLANDS -8.466 157.044


(b)

Tsunami RUnups where Runup Country = SOLOMON ISLANDS

View parameter des r pbOns and access statistical information by chicking on column headings.

For additional Information about the tsunamigenic earthquake, tsunami runup, or source event edick on the links in the Cause EQ Nag, AMR Src Info or Addl Runup Into columns.

[45]

Voir M

Tsunami Source Mal InfoBate Tsu Doubt-

Cau Tsu EQ Vol- Tsu tultry Hr Min Sec Val Code Sm Meg cano Runup Runup

Tsunami Runup Location Tsunami Runup MeasurementsMax

Inundation 1stDistance Type Per Mtn

Tt

Deaths

Mum DeCountry Name

Travel Time MaxDistance Water

Latitude Longitude from Source Hrs Mill Heightr1857 17 4 4 * 8.0 s SOLOMON ISLANDS W. NEW BRITAIN'1986 15,16: 4 18 4 1 0 1.4 r SOLOMON ISLANDS VITIAZ STRAIT 1.50

1931 1 I 31191 131 131 4 1 * 7.9 r SOLOMON ISLANDS ;IRA KIRA, SOLOMON ISLANDS .10.4501 161.930: 29,5Í

2.001931 1 E 3 19 13 13x4 1 * 7.9 o (SOLOMON ISLANDS (PORT MARY, SOLOMON ISLANDS

13.00 F

1931 1 I E9 131 3E4 1 1 I ° 17.9 a (SOLOMON ISLANDS í,SAN CRISTOBAL ISLAND1 -10.6881 161.750I- 11.1 r 9.00 F 50 1

1939 130 21 781 z71 1 ' 7.8 SOLOMON ISLANDS AIS1. 2.oó1939 130 .151.0 E

1

1 .1 131. c (SOLOMON ISLANDS IBEAUFORT BAY, GUADALCANAL 1 -9.8091 í6o.0001 181.71

10.501939 30Er .51013

1

1 1 8.1 v ISOLOMON ISLANDS IIRUSSELL I.1 -9.0501 159:2001 178.5 12 1

1952 1 179 I.- s8 1 .T nr 1 9.6 ISQLOMaN ISLANDS 15í455I IS. .901955 1 8 1 3 2Tí 16x3

1

1 ''' 1SOLOMON ISLANDS FAURD I.1 -6.9381 156.8801 42.1

1957 1 E2 11 rE° w ',SOLOMON ISLANDS 1AFFO, NW MALAITA 1 -9.0011 161.000 2.70

1957.1 SOLOMON ISLANDS 1FAUA00, NW MALARA -8.570 160.720 2J011959.1 z2r Q a0 r4 rni Z3 SOLOMON ISLANDS IVELLA LIVELLI I. -7.75D 156.5801 69.7 1,10119611 rf8 r2 1 SOLOMON ISLANDS GUADALCANAL 1-3.6019611-r38

119fi11-7751r2 0 SOLOMON ISLANDS (SAN CRISTOBAL ISLAND

1 -10.6011 161.7501

3.6039 53:219r* 6.6 SOLOMON ISLANDS 5. COAST 80

1 19661- 51-0 1 1 7.6 SOLOMON ISLANDS POINT CRUZ ;HONIARA) -9.4711 159.9581 131.11 .11 1

119661 1151 01 591 8r3 1 7.6 SOLOMON ISLANDS S.o.N CRISTOBAL ISLAND -10.6001. 161.7511 109.119fifi'1 73 (SOLOMON ISLANDS MOHAW K BAY, SANTA CRUZ ISLANDS -10.000' 166.2001 197.2

1 19661 3I 181 231 3.9E4 1 7.5 (SOLOMON ISLANDS 1VANIKOLO (VANIKORO), SANTA CRUZ IS. 1 -11.617 166.9671 54.81

2.80

1 296611 11151M r9 1 7.3 (SOLOMON ISLANDS 'VANIKOLO (VANIKORO), SANTA CRUZ IS. 111.617 166.967: 3318 1 1.5079711 1141 61 11129.1 4 9 rr .9 SOLOMON ISLANDS KUNUA

119711-r261-1 23 22.3E4 1 .1Th.9 (SOLOMON ISLANDS (NORTH SOLOMON SEA 1 3.00

119711 16'10- 6 t I Vol (SOLOMON ISLANDS (NEO VILLAGE, TRAVANION ISLAND

I97217. 173 (SOLOMON ISLANDS 1RIAZ STRAIT119741 '3123 30' 5.3, 4 ' 1 *'7.0 (SOLOMON ISLANDS 1kOROVU, SHORTLAND ISLAND -7.1091 155.6001 55.5 1.501 19741 1 3 12 33.1 4 1 v 7.1 IsOLOMON ISLANDS 1CHOTSEHL -7.0131 157.000' 158.4 4.5014. 1 3 12 33.1 4 1 * 7.1 (SOLOMON ISLANDS (HONIARA, GUADALCANAL -9.433 159.9501 529.3 15 2

1977 20 23 13 10.4 4 1 6.8 SOLOMON ISLANDS 1HONIARA, GUADALCANAL -9.4331 159.9501 372.51 .15 2

1977 20 23 13' 10.41 4 1 6.8 SOLOMON ISLANDS -11.5101 160.0001 408.0, 1977

1987',20 23 92'50.51 418 14 3.15.1

', 1 ;7.6Ì II * 16.6.D

(SOLOMON ISLANDS

1R,ENNELL

IRENNELL -11.508 160.000 183.1(SOLOMON ISLANDS (SOLOMON ISLANDS -10.707 162.326

11988( 10 4 38,26.114 1 (SOLOMON ISLANDS NONDARA, GUADALCANAL -9.4331 159.950 140.81

.09 r 219881 1101 41 38126.1 1 (SOLOMON ISLANDS (SAN CRISTOBAL ISLAND -10.610 I.61.750 105.1 I 110.00 I- 1 ' -41-i1911-1 9561 18 59.3r4 9rr 7.6 (SOLOMON ISLANDS (HONIARA, GUADALCANAL -1433 159.9501-104.5 IC:i 181:1.4 91 18

1 299111 14 IS 58 12.7E4 1 73 (SOLOMON ISLANDS (HONIARA, GUADALCANAL -9.4331 159.950 170.11

.15 1 2

11992 1 7.1 SOLOMON.ISLANDS !SANTA CRUZ ISLANDS -10.7511 165.920 85.119971 21112r 26.4r4 9 SOLOMON ISLANDS 1CRGWDY HEAD IS., SANTA CRUZ ISLANDS -11750 r 165.920 220.0

1 1997 21 121 2 26nr9 1 7.7 (SOLOMON ISLANDS (LORD HOWE ISLAND, SANTA CRUZ ISLAND -10.7501 165.920 220.0

11997 1- 21 121 2 26.414 1 1" 7.7 (SOLOMON ISLANDS 1i0WEED HEAD IS., SANTA CRUZ ISLANDS -10.7501 165.920 220.02000rn767 54 56.7r49f* e6 (SOLOMON ISLANDS ICi ZO ISLAND -8.070 156.8005.0 80

1200011 161 4 s4 Se.7r4 1 r+ sG (SOLOMON ISLANDS ÏORO -8.2201 157.220 731.01

1.00031

201 931 614757 13.59r*1 7.3

6.3SOLOMON ISLANDS (SAN CRISTOBAL ISLAND -10.6811 161.750 107.8 9(SOLOMON ISLANDS [HONIARA, GUADALCANAL -9.433' 159.950 6266.8 :.1.4

20071-1510 1.fir4 1 zi (SOLOMON ISLANDS 1HONIARA, GUADALCANAL1 -9.4331 159.950 1501.4 11471 .52 1 2 rß

0071 56.3E9 1 rr 9I SOLOMON ISLANDS 11CHDSSE1IL ISLAND, NEW GEORGIA GROUP 1.0131 157.011 153.2 1 1

r20D7r-ri73 s9156.31a 9 6.1 . DMON ISLANDS LGIZO ISLAND, NEW GEORGIA GROUPI -0.567 156.800 51.3 9

12007E r 1126 39 s6s1 B.2 9 'SOLOMON ISLANDS 11-EONARA, GUADALCANAL ISLAND 'I -9.4331 159.950 337.11 PI 451 .21 1 220071 1 11731 39156.31 * B.1 'SOLOMON ISLANDS 1KOLOMBANGARA IS, NEW GEORGIA GROUP -8.0001 157.167 52.9 9

'20071-112D 39 56.3M9'* 131. SOLOMON ISLANDS IMUNDA, NEW GEORGIA ISLAND 18.3171 157.250 27.7 1 1

12007 1-1 l E201 39.1 56.31 4 1Th B.1*

'SOLOMON ISLANDS WIG, NEW GEORGIA ISLAND -I -8.2171 157.217 33.11

1

1 2007 E E1120 a9 E55.3 f 1 8.1 'SOLOMON ISLANDS IRANONGGA ISLAND, NEW GEORGIA GROUP 'I -8.0671 155.533 71.2 1 1

120071 1 39155.3 1 1 I* 19.1 'SOLOMON ISLANDS [SANTA ISABEL ISLAND 1 -8.0431 159.454 269.31

1

1-2o0717l20 39 s6.3ra * 131_ SOLOMON ISLANDS 1SHORTLANDS ISLANDS, W PROVINCE -6.917 155.883 214.1 9.10071-1 16.1 'SOLOMON ISLANDS 1511110 ISLAND, NEW GEORGIA GROUP

1-8.2831 156.550 57.1 1 1

z1D7r 112D 9 LW' f 1 rf r9.1 'SOLOMON ISLANDS 'VELLA LAMELLA FS, NEW GEORGIA GROUP 50 156.667 89.2 9


[46]

2 Recent PTWC Warnings

(i) Solomon Islands 2 April 2007 Tsunami

USGS

M8.1 Solomon Islands Earthquake of 1 April 2007Tam Swung PpiceirmrlAegrori

ENrCSN

®o®®mmi-'amm9®®o®®®

r:,....,....w. .°,.,..-..._.....,..

SYiu,,,r H rslMrill '

-2;:--` III rç.=ME

enin ' 1 ..-'

Firrirc FmrltModei

EPLANAIIqi

®a

rlFigure A2 -1: USGS Poster of Solomon Islands 2 April 2007 Earthquake (http: / /earthquake.usgs.gov).

TSUNAMI POTENTIAL (RELATIVE TO EARTHQUAKE DISLOCATION)

12BE 130E ICE 150E 1500 170E 180

ISOM

lax

oo' 120'

Estimated Tsunami Travel Time (Hours)

193' lao' 210' Zao' no'

120' 150' 210' 240 270'Planed 71 Pp 2,7- 22.1.7G

Figure A2 -2: Travel times map and model scenario for Solomon's tsunami 2 April 2007.

ao'

o'

The Solomon Trench earthquake of 2 April 2007 is described in the USGS poster at Figure A2-1. The model scenario and forecast travel times for the tsunami are shown at Figure A2 -2. TheSolomon Islands warning points used by the PTWC are at Table A2 -2 and the PTWC Warningsfor this event are below. During the PTWC expanding warning /watch phase, any of thelocations below is within 3 hour (warning) or 6 hours (watch) travel time for the predicted


[47]

expanding tsunami, all the Solomon Islands will be included in the warning /watch process.Travel times are then provided for all Solomon Islands locations whether in warning or watchrange. Note that the initial estimate of magnitude was 7.8 and a regional (see A2 4(i)) warningcovering 1000 km / 3 hours travel time was issued. In the second warning the estimate ofmagnitude was increased to 8.1 and an expanding warning /watch phase was initiated forpotentially Ocean -wide tsunami. The forecast travel time to Honiara from source was 40minutes from the earthquake, 25 minutes after first PTWC bulletin issued.

Table A2 -2: Solomon Islands warning locations used by PTWC.

MUNDA 8.4S 157.2E Rendova IslandFALAMAE 7.4S 155.6E Mono IslandPANGGOE 6.9S 157.2E Choiseul IslandHONIARA 9.3S 160.0E GuadalcanalGHATERE 7.8S 159.2E Santa Isabel IslandAUKI 8.8S 160.6E Malaita IslandKIRAKIRA 10.4S 161.9E San Cristobal Island

VILNA /LAU ISPAPUA

NEW GUINEABake

Bougainville

NfIKUMANU IS

TAUU IS.

l YONTONG .,

S ATOLL

e' Choiseuf 1 NF.- lMr T 1

Santa \vexa \ 1b! MALAITALere11N. #phme.nge.e OeiWESTERN "'"i ,Bim Géóqie l

SOUTHPACIFICOCEAN

RosselIsland

'regale

/NEW GEORGIA /II Yen9- I s 51eWenl

ISLANDS Rena . FLOa41A -ÇI R SELL is 15LAN 5

1 Pa.a.e . ', Malaria e)-'-1eni/ 1"1"'..4.askai LP

WawaGuadalcanaf .. `

Solomon Sea

Solomon Islands--- Lino of separation

(not a formal internationalboundary or territorial limit)

- -- District boundary

* National capital

o District capital

Io

50 100 1$0 200 I(IOaters

6 5Q lÓ0 150 200 Miles

Dal

PARIAr EM! GOURE\

AUSTRALIA

IePetificIÑ!tlNa,

NAURU

SOLOMONiSLANUS

VANUATU'-

Cel ma

KIRIBATI

TUYALU

FUI

nelNeee W9.1Raw ntl

NS)

WESTERN

IU s;

TONGA

NU cm,w>r

F+zl

CENTRAL : Lira near GLAND ie9y

Sanm

EASTERN 9Cristobal - Nendá

G-c`

Ballone I. I./tepee ÑRennelf Yenikalo ÿ

0N

Coral Se.

Artute Is.

. Peaks

TORRESlsueas

Ma. LewVanua Lava BANKS ISLANDS

SanteMarie ,MOM

VANUATU

Espiritu Santo Aune

Lapwide

Malakula

Meéwa

Penrecest

Amborm

Ear

ase 504-633(645714) 4-81

Figure A2 -3: Locations of PTWC warning reference points in Solomon Islands based on Table A2 -2.


[48]

Example 1:PTWC Bulletin No 1

TSUNAMI BULLETIN NUMBER 001

PACIFIC TSUNAMI WARNING CENTER /NOAA/NWSISSUED AT 2055Z 01 APR 2007

THIS BULLETIN IS FOR ALL AREAS OF THE PACIFIC BASIN EXCEPTALASKA - BRITISH COLUMBIA - WASHINGTON - OREGON - CALIFORNIA.

... A TSUNAMI WARNING IS IN EFFECT ...

A TSUNAMI WARNING IS IN EFFECT FOR

SOLOMON IS. / PAPUA NEW GUINEA

FOR ALL OTHER PACIFIC AREAS, THIS MESSAGE IS AN ADVISORY ONLY.

AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS

ORIGIN TIME - 2040Z 01 APR 2007COORDINATES - 8.6 SOUTH 157.2 EASTLOCATION - SOLOMON ISLANDSMAGNITUDE - 7.8

EVALUATION

IT IS NOT KNOWN THAT A TSUNAMI WAS GENERATED. THIS WARNING ISBASED ONLY ON THE EARTHQUAKE EVALUATION. AN EARTHQUAKE OF THISSIZE HAS THE POTENTIAL TO GENERATE A DESTRUCTIVE TSUNAMI THAT CANSTRIKE COASTLINES IN THE REGION NEAR THE EPICENTER WITHIN MINUTESTO HOURS. AUTHORITIES IN THE REGION SHOULD TAKE APPROPRIATEACTION IN RESPONSE TO THIS POSSIBILITY. THIS CENTER WILL MONITORSEA LEVEL GAUGES NEAREST THE REGION AND REPORT IF ANY TSUNAMIWAVE ACTIVITY IS OBSERVED. THE WARNING WILL NOT EXPAND TO OTHERAREAS OF THE PACIFIC UNLESS ADDITIONAL DATA ARE RECEIVED TOWARRANT SUCH AN EXPANSION.

ESTIMATED INITIAL TSUNAMI WAVE ARRIVAL TIMES. ACTUAL ARRIVAL TIMESMAY DIFFER AND THE INITIAL WAVE MAY NOT BE THE LARGEST. THE TIMEBETWEEN SUCCESSIVE TSUNAMI WAVES CAN BE FIVE MINUTES TO ONE HOUR.

LOCATION COORDINATES ARRIVAL TIME

SOLOMON IS. MUNDA 8.4S 157.2E 2039Z 01 APRFALAMAE 7.4S 155.6E 2059Z 01 APRPANGGOE 7.0S 157.5E 2108Z 01 APRGHATERE 7.5S 159.0E 2117Z 01 APRHONIARA 9.0S 160.0E 2120Z 01 APRAUKI 8.8S 160.6E 2130Z 01 APRKIRAKIRA 10.05 162.0E 2136Z 01 APR

PAPUA NEW GUINE AMUN 6.0S 154.7E 2116Z 01 APRKIETA 6.1S 155.6E 2123Z 01 APRRABAUL 4.2S 152.3E 2145Z 01 APRLAE 6.8S 147.0E 2214Z 01 APRKAVIENG 2.5S 150.7E 2216Z 01 APRMADANG 5.2S 145.8E 2241Z 01 APRMANUS IS. 2.0S 147.5E 2250Z 01 APRPORT MORESBY 9.3S 146.9E 2252Z 01 APRWEWAK 3.5S 144.0E 2319Z 01 APRVANIMO 2.6S 141.3E 2346Z 01 APR

BULLETINS WILL BE ISSUED HOURLY OR SOONER IF CONDITIONS WARRANT.THE TSUNAMI WARNING WILL REMAIN IN EFFECT UNTIL FURTHER NOTICE.

THE JAPAN METEOROLOGICAL AGENCY MAY ALSO ISSUE TSUNAMI MESSAGESFOR THIS EVENT TO COUNTRIES IN THE NORTHWEST PACIFIC AND SOUTHCHINA SEA REGION. IN CASE OF CONFLICTING INFORMATION... THEMORE CONSERVATIVE INFORMATION SHOULD BE USED FOR SAFETY.

THE WEST COAST /ALASKA TSUNAMI WARNING CENTER WILL ISSUE BULLETINSFOR ALASKA - BRITISH COLUMBIA - WASHINGTON - OREGON - CALIFORNIA.


[49]




... A TSUNAMI WARNING AND WATCH ARE IN EFFECT ...


SOLOMON IS. / PAPUA NEW GUINEA / VANUATU / NAURU / CHUUK /NEW CALEDONIA / POHNPEI / KOSRAE / AUSTRALIA / INDONESIA /TUVALU / KIRIBATI / MARSHALL IS.

A TSUNAMI WATCH IS IN EFFECT FOR

GUAM / FIJI / N. MARIANAS / YAP / HOWLAND -BAKER /WALLIS- FUTUNA / BELAU / TOKELAU / KERMADEC IS / SAMOA /NEW ZEALAND / MARCUS IS. / WAKE IS. / AMERICAN SAMOA / TONGA /NIUE / COOK ISLANDS / PHILIPPINES / JARVIS IS. / PALMYRA IS. /JOHNSTON IS. !JAPAN




EVALUATION

IT IS NOT KNOWN THAT A TSUNAMI WAS GENERATED. THIS WARNING ISBASED ONLY ON THE EARTHQUAKE EVALUATION. AN EARTHQUAKE OF THISSIZE HAS THE POTENTIAL TO GENERATE A DESTRUCTIVE TSUNAMI THAT CANSTRIKE COASTLINES NEAR THE EPICENTER WITHIN MINUTES AND MOREDISTANT COASTLINES WITHIN HOURS. AUTHORITIES SHOULD TAKEAPPROPRIATE ACTION IN RESPONSE TO THIS POSSIBILITY. THIS CENTERWILL MONITOR SEA LEVEL DATA FROM GAUGES NEAR THE EARTHQUAKE TODETERMINE IF A TSUNAMI WAS GENERATED AND ESTIMATE THE SEVERITY OFTHE THREAT.



SOLOMON IS. MUNDA 8.4S 157.2E 2039Z 01 APRFALAMAE 7.4S 155.6E 2103Z 01 APRPANGGOE 6.9S 157.2E 2120Z 01 APRHONIARA 9.3S 160.0E 2121Z 01 APRGHATERE 7.8S 159.2E 2122Z 01 APRAUKI 8.8S 160.6E 2134Z 01 APRKIRAKIRA 10.45 161.9E 2140Z 01 APR

PAPUA NEW GUINE AMUN 6.0S 154.7E 2124Z 01 APRKIETA 6.1S 155.6E 2133Z 01 APRRABAUL 4.2S 152.3E 2145Z 01 APRLAE 6.8S 147.0E 2218Z 01 APRKAVIENG 2.5S 150.7E 2223Z 01 APRMADANG 5.2S 146.0E 2241Z 01 APRPORT MORESBY 9.5S 147.0E 2254Z 01 APRMANUS IS. 2.0S 147.5E 2259Z 01 APRWEWAK 3.5S 143.6E 2325Z 01 APRVANIMO 2.6S 141.3E 2350Z 01 APR

VANUATU ESPERITU SANTO 15.15 167.3E 2236Z 01 APRANATOM IS. 20.25 169.9E 2322Z 01 APR

NAURU NAURU 0.5S 166.9E 23112 01 APRCHUUK CHUUK IS. 7.4N 151.8E 2329Z 01 APRNEW CALEDONIA NOUMEA 22.35 166.5E 2338Z 01 APRPOHNPEI POHNPEI IS. 7.ON 158.2E 2345Z 01 APRKOSRAE KOSRAE IS. 5.5N 163.0E 2345Z 01 APRAUSTRALIA CAIRNS 16.75 145.8E 2349Z 01 APR

BRISBANE 27.25 153.3E 0033Z 02 APR


[50]

INDONESIA

SYDNEYGLADSTONEMACKAYHOBART

JAYAPURA

33.9S 151.4E23.8S 151.4E21.1S 149.3E43.3S 147.6E2.4S 140.8E

0114Z 02 APR0139Z 02 APR0144Z 02 APR0245Z 02 APR

2354Z 01 APRWARSA 0.6S 135.8E 0037Z 02 APRMANOKWARI 0.8S 134.2E 0056Z 02 APR

PATANI 0.4N 128.8E 0158Z 02 APRGEME 4.8N 126.8E 0202Z 02 APRMANADO 1.5N 124.8E 0242Z 02 APRTARAKAN 3.3N 117.6E 0400Z 02 APRSINGKAWANG 1.ON 108.8E 1240Z 02 APRPANGKALPINANG 2.OS 106.2E 1547Z 02 APR

TUVALU FUNAFUTI IS. 7.9S 178.5E 2359Z 01 APRKIRIBATI TARAWA IS. 1.5N 173.0E 0007Z 02 APR

KANTON IS. 2.8S 171.7W 0121Z 02 APRCHRISTMAS IS. 2.ON 157.5W 0325Z 02 APRMALDEN IS. 3.9S 154.9W 0336Z 02 APRFLINT IS. 11.4S 151.8W 0408Z 02 APR

MARSHALL IS. KWAJALEIN 8.7N 167.7E 0022Z 02 APRMAJURO 7.1N 171.4E 0028Z 02 APRENIWETOK 11.4N 162.3E 0037Z 02 APR

GUAM GUAM 13.4N 144.7E 0035Z 02 APRFIJI SUVA 18.1S 178.4E 0038Z 02 APRN. MARIANAS SAIPAN 15.3N 145.8E 0041Z 02 APRYAP YAP IS. 9.5N 138.1E 0048Z 02 APRHOWLAND -BAKER HOWLAND IS. 0.6N 176.6W 0057Z 02 APRWALLIS -FUTUNA WALLIS IS. 13.2S 176.2W O100Z 02 APRBELAU MALAKAL 7.3N 134.5E 0103Z 02 APRTOKELAU NUKUNONU IS. 9.2S 171.8W 0119Z 02 APRKERMADEC IS RAOUL IS. 29.2S 177.9W 0131Z 02 APRSAMOA APIA 13.8S 171.8W 0135Z 02 APRNEW ZEALAND NORTH CAPE 34.4S 173.3E 0138Z 02 APR

EAST CAPE 37.5S 178.5E 0214Z 02 APRAUCKLAND(W) 37.1S 174.2E 0238Z 02 APRGISBORNE 38.7S 178.0E 0247Z 02 APRMILFORD SOUND 44.5S 167.8E 0249Z 02 APRNEW PLYMOUTH 39.15 174.1E 0310Z 02 APRNAPIER 39.55 176.9E 0316Z 02 APRWESTPORT 41.85 171.2E 0332Z 02 APRAUCKLAND(E) 36.7S 175.0E 0332Z 02 APRWELLINGTON 41.5S 174.8E 0333Z 02 APRBLUFF 46.65 168.3E 0351Z 02 APRNELSON 41.3S 173.3E 0426Z 02 APRLYTTELTON 43.6S 172.7E 0439Z 02 APRDUNEDIN 45.9S 170.5E 0506Z 02 APR

MARCUS IS. MARCUS IS. 24.3N 154.0E 0138Z 02 APRWAKE IS. WAKE IS. 19.3N 166.6E 0141Z 02 APRAMERICAN SAMOA PAGO PAGO 14.35 170.7W 0144Z 02 APRTONGA NUKUALOFA 21.0S 175.2W 0152Z 02 APRNIUE NIUE IS. 19.0S 170.0W 0209Z 02 APRCOOK ISLANDS PUKAPUKA IS. 10.8S 165.9W 0212Z 02 APR

PENRYN IS. 8.9S 157.8W 0316Z 02 APRRAROTONGA 21.2S 159.8W 0324Z 02 APR

PHILIPPINES DAVAO 6.8N 125.7E 0215Z 02 APRLEGASPI 13.2N 124.0E 0248Z 02 APRZAMBOANGA 7.ON 122.2E 0256Z 02 APRPALANAN 17.1N 122.6E 0307Z 02 APRLAOAG 18.2N 120.6E 0352Z 02 APRPUERTO PRINCESA 9.8N 119.0E 0404Z 02 APRSAN FERNANDO 16.6N 120.3E 0421Z 02 APRILOILO 10.8N 122.8E 0438Z 02 APRMANILA 14.5N 120.8E 0517Z 02 APR

JARVIS IS. JARVIS IS. 0.4S 160.1W 0256Z 02 APRPALMYRA IS. PALMYRA IS. 6.3N 162.4W 0300Z 02 APRJOHNSTON IS. JOHNSTON IS. 16.7N 169.5W 0308Z 02 APRJAPAN KATSUURA 35.1N 140.3E 0312Z 02 APR

OKINAWA 26.2N 128.0E 0318Z 02 APRSHIMIZU 32.8N 132.8E 0359Z 02 APRKUSHIRO 42.8N 144.2E 0410Z 02 APRHACHINOHE 40.5N 141.8E 0415Z 02 APR

BULLETINS WILL BE ISSUED HOURLY OR SOONER IF CONDITIONS WARRANT.THE TSUNAMI WARNING AND WATCH WILL REMAIN IN EFFECT UNTILFURTHER NOTICE.


[51]




NOTE: AREAS TO THE NORTH OF THE SOLOMON ISLANDS SHOULD NOTBE SIGNIFICANTLY AFFECTED

... A TSUNAMI WARNING AND WATCH ARE IN EFFECT ...


SOLOMON IS. / PAPUA NEW GUINEA / VANUATU / NEW CALEDONIA /NORTHEASTERN AUSTRALIA / TUVALU / KIRIBATI / FIJI /KERMADEC IS / NEW ZEALAND




MEASUREMENTS OR REPORTS OF TSUNAMI WAVE ACTIVITY

GAUGE LOCATION LAT LON TIME AMPL PER

MANUS PG 2.0S 147.4E 0040Z 0.09M = 0.3FT 40MINVANUATU VU 17.85 168.3E 0114Z 0.14M = 0.5FT 28MINHONIARA SB 9.4S 160.0E 2308Z 0.20M = 0.6FT 62MIN

LAT - LATITUDE (N= NORTH, S= SOUTH)LON - LONGITUDE (E =EAST, W =WEST)TIME - TIME OF THE MEASUREMENT (Z = UTC = GREENWICH TIME)AMPL - TSUNAMI AMPLITUDE MEASURED RELATIVE TO NORMAL SEA LEVEL.

IT IS ...NOT... CREST -TO- TROUGH WAVE HEIGHT.IT IS ...NOT... CREST -TO- TROUGH WAVE HEIGHT.VALUES ARE GIVEN IN BOTH METERS (M) AND FEET (FT).

PER - PERIOD OF TIME IN MINUTES(MIN) FROM ONE WAVE TO THE NEXT.

NOTE: PTWC HAS RECEIVED REPORTS OF TSUNAMI RELATED FATALITIES INSOUTHEAST PAPUA NEW GUINEA AND THE SOLOMON ISLANDS.

EVALUATION

SEA LEVEL READINGS INDICATE A TSUNAMI WAS GENERATED. IT MAY HAVEBEEN DESTRUCTIVE ALONG COASTS NEAR THE EARTHQUAKE EPICENTER ANDCOULD ALSO BE A THREAT TO MORE DISTANT COASTS. AUTHORITIES SHOULDTAKE APPROPRIATE ACTION IN RESPONSE TO THIS POSSIBILITY. THISCENTER WILL CONTINUE TO MONITOR SEA LEVEL DATA TO DETERMINE THEEXTENT AND SEVERITY OF THE THREAT.

FOR ALL AREAS - WHEN NO MAJOR WAVES ARE OBSERVED FOR TWO HOURSAFTER THE ESTIMATED TIME OF ARRIVAL OR DAMAGING WAVES HAVE NOTOCCURRED FOR AT LEAST TWO HOURS THEN LOCAL AUTHORITIES CAN ASSUMETHE THREAT IS PASSED. DANGER TO BOATS AND COASTAL STRUCTURES CANCONTINUE FOR SEVERAL HOURS DUE TO RAPID CURRENTS. AS LOCALCONDITIONS CAN CAUSE A WIDE VARIATION IN TSUNAMI WAVE ACTION THEALL CLEAR DETERMINATION MUST BE MADE BY LOCAL AUTHORITIES.



SOLOMON IS. MUNDA 8.4S 157.2E 2039Z 01 APRFALAMAE 7.4S 155.6E 2103Z 01 APRPANGGOE 6.9S 157.2E 2120Z 01 APRHONIARA 9.3S 160.0E 2121Z 01 APRGHATERE 7.8S 159.2E 2122Z 01 APRAUKI 8.8S 160.6E 2134Z 01 APRKIRAKIRA 10.45 161.9E 2140Z 01 APR


[52]

PAPUA NEW GUINE AMUN 6.OS 154.7E 21242 01 APRKIETA 6.1S 155.6E 21332 01 APRRABAUL 4.2S 152.3E 21452 01 APRLAE 6.8S 147.0E 22182 01 APRKAVIENG 2.5S 150.7E 22232 01 APRMADANG 5.2S 146.0E 22412 01 APRPORT MORESBY 9.5S 147.0E 22542 01 APRMANUS IS. 2.0S 147.5E 22592 01 APRWEWAK 3.5S 143.6E 23252 01 APRVANIMO 2.6S 141.3E 23502 01 APR

VANUATU ESPERITU SANTO 15.15 167.3E 22362 01 APRANATOM IS. 20.25 169.9E 23222 01 APR

NEW CALEDONIA NOUMEA 22.35 166.5E 23382 01 APRAUSTRALIA CAIRNS 16.75 145.8E 23492 01 APR

BRISBANE 27.25 153.3E 00332 02 APRSYDNEY 33.95 151.4E 01142 02 APRGLADSTONE 23.85 151.4E 01392 02 APRMACKAY 21.15 149.3E 01442 02 APRHOBART 43.35 147.6E 02452 02 APR

TUVALU FUNAFUTI IS. 7.9S 178.5E 23592 01 APRKIRIBATI TARAWA IS. 1.5N 173.0E 00072 02 APR

KANTON IS. 2.8S 171.7W 01212 02 APRCHRISTMAS IS. 2.ON 157.5W 03252 02 APRMALDEN IS. 3.9S 154.9W 03362 02 APRFLINT IS. 11.45 151.8W 04082 02 APR

FIJI SUVA 18.15 178.4E 00382 02 APRKERMADEC IS RAOUL IS. 29.25 177.9W 01312 02 APRNEW ZEALAND NORTH CAPE 34.45 173.3E 01382 02 APR

EAST CAPE 37.55 178.5E 02142 02 APRAUCKLAND(W) 37.15 174.2E 02382 02 APRGISBORNE 38.75 178.0E 02472 02 APRMILFORD SOUND 44.55 167.8E 02492 02 APRNEW PLYMOUTH 39.15 174.1E 03102 02 APRNAPIER 39.55 176.9E 03162 02 APRWESTPORT 41.85 171.2E 03322 02 APRAUCKLAND(E) 36.75 175.0E 03322 02 APRWELLINGTON 41.55 174.8E 03332 02 APRBLUFF 46.65 168.3E 03512 02 APRNELSON 41.35 173.3E 04262 02 APRLYTTELTON 43.65 172.7E 04392 02 APRDUNEDIN 45.95 170.5E 05062 02 APR

BULLETINS WILL BE ISSUED HOURLY OR SOONER IF CONDITIONS WARRANT.THE TSUNAMI WARNING AND WATCH WILL REMAIN IN EFFECT UNTILFURTHER NOTICE.

TSUNAMI BULLETIN NUMBER 004PACIFIC TSUNAMI WARNING CENTER /NOAA /NWSISSUED AT 00132 02 APR 2007


NOTE: AREAS TO THE NORTH OF THE SOLOMONS SHOULDNOT BE SIGNIFICANTLY AFFECTED.

... A TSUNAMI WARNING AND WATCH REMAINS IN EFFECT ...A TSUNAMI WARNING IS IN EFFECT FOR

SOLOMON IS. / PAPUA NEW GUINEA / VANUATU /NEW CALEDONIA / AUSTRALIA /TUVALU / KIRIBATI / FIJI

A TSUNAMI WATCH IS IN EFFECT FOR

KERMADEC / NEW ZEALAND





[53]


GAUGE LOCATION

HONIARA SBVANUATU VU

LAT LON TIME AMPL PER

9.4S 160.0E 22352 0.14M = 0.5FT 70MIN17.85 168.3E 23512 0.11M = 0.4FT 26MIN

LAT LATITUDE (N= NORTH, S= SOUTH)LON LONGITUDE (E =EAST, W =WEST)TIME TIME OF THE MEASUREMENT (Z = UTC = GREENWICH TIME)AMPL TSUNAMI AMPLITUDE MEASURED RELATIVE TO NORMAL SEA LEVEL.

IT IS ...NOT... CREST -TO- TROUGH WAVE HEIGHT.IT IS ...NOT... CREST -TO- TROUGH WAVE HEIGHT.VALUES ARE GIVEN IN BOTH METERS(M) AND FEET(FT).

PER PERIOD OF TIME IN MINUTES(MIN) FROM ONE WAVE TO THE NEXT.

EVALUATION

SEA LEVEL READINGS INDICATE A TSUNAMI WAS GENERATED. IT MAY HAVEBEEN DESTRUCTIVE ALONG COASTS NEAR THE EARTHQUAKE EPICENTER ANDCOULD ALSO BE A THREAT TO MORE DISTANT COASTS. AUTHORITIES SHOULDTAKE APPROPRIATE ACTION IN RESPONSE TO THIS POSSIBILITY. THISCENTER WILL CONTINUE TO MONITOR SEA LEVEL DATA TO DETERMINE THEEXTENT AND SEVERITY OF THE THREAT.

FOR ALL AREAS - WHEN NO MAJOR WAVES ARE OBSERVED FOR TWO HOURSAFTER THE ESTIMATED TIME OF ARRIVAL OR DAMAGING WAVES HAVE NOTOCCURRED FOR AT LEAST TWO HOURS THEN LOCAL AUTHORITIES CAN ASSUMETHE THREAT IS PASSED. DANGER TO BOATS AND COASTAL STRUCTURES CANCONTINUE FOR SEVERAL HOURS DUE TO RAPID CURRENTS. AS LOCALCONDITIONS CAN CAUSE A WIDE VARIATION IN TSUNAMI WAVE ACTION THEALL CLEAR DETERMINATION MUST BE MADE BY LOCAL AUTHORITIES.

ESTIMATED INITIAL TSUNAMI WAVE ARRIVAL TIMES. ACTUAL ARRIVAL TIMESMAY DIFFER AND THEBETWEEN SUCCESSIVE

LOCATION

INITIALTSUNAMI

WAVE MAY NOT BE THE LARGEST. THE TIMEWAVES CAN BE FIVE MINUTES TO ONE HOUR.

COORDINATES ARRIVAL TIME

SOLOMON IS. MUNDA 8.4S 157.2E 20392 01 APRFALAMAE 7.4S 155.6E 21032 01 APRPANGGOE 6.9S 157.2E 21202 01 APRHONIARA 9.3S 160.0E 21212 01 APRGHATERE 7.8S 159.2E 21222 01 APRAUKI 8.8S 160.6E 21342 01 APRKIRAKIRA 10.45 161.9E 21402 01 APR

PAPUA NEW GUINE AMUN 6.0S 154.7E 21242 01 APRKIETA 6.1S 155.6E 21332 01 APR


0.008 3 DART524020.0040.900 ÿ ;

-0.904

0.008 =

120 240 360 480 600

0.008 3 DARi524030.0040.000

-0.004 --0.008 =

040.20.0

- 0.2

- 0.4

1.20.80.40.0

`n -0.4¢ -0.8

-1.2

15°

[54]

2007 Solomon Earthquake

120 240 360 480 600

Rabaul

![J!ryf

120 240 360

-10°

480 600

0 120 240 360 480 600

Time (min)

-20°

-25°

-30"140° 150° 160" 170° 180' 190

0.05 0.20

"Mini

0.00 0.10

Water height (m)0.15

Figure A2 -4: Tide gauge recordings for Solomon Islands tsunami 2 April, 2007

1.20.80.40.0

-0.4-0k1.2

0.4

020.2

0-0.4

0.4

0.2

0.0

-0.2

.0.4 F-. . ... . .

0 120 240 360 480 600

0 120 240 360 480 600

0 120 240 300 480

oA - Noumera0.2 -

0.0

-0.2

0.40 120 240 360 480

Time [min}

Figure A2 -5: Tide gauge recording for 2 April 2007 tsunami over the deep -water model scenario closestto the event.


602

600

(a)

[55]

HONIARA, GUADALCANAL, SOLOMON ISLANDS - LAST 24 HOURSLAT 9 25.3' S LONG 159 57.3' E

SIX MINUTE OBSERVATIONS & PREDICTIONS TO 20:54 02 APR 2007 UTC

1.2

1.0

0.8G1

ö1

E0.6

(b)

0.4

0.2

20 21 22 23 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21

01 April 2007 02 April 2007

PRE

BS

r

HONIARA, GUADALCANAL, SOLOMON ISLANDS - LAST 24 HOURSLAT 9° 25.3' S LONG 159° 57.3' E

SIX MINUTE RESIDUALS TO 20:54 02 APR 2007 UTC

0.5

0.4

0.3

0.2

_0 -2

-0.3

-0.4

-0.5

20 21 22 23 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21

01 April 2007 02 April 2007

Figure A2 -6: Tide gauge recording at Honiara for 2 April 2007 tsunami (a) Tide and tsunami signal (b)tsunami signal with predicted tide removed (ABoM)


(a)

(b)

15E

1.6

1.4

1.2

1.0N

46 0.8

E0.6

0.5

0.4

0.3

0.2

0.1

-0.0

-0.1

-0.2

-0.3

-0.4

0.4

0.2

0.0

[56]

PORT VILA, EFATE, VANUATU - LAST 24 HOURSLAT 17' 45.7' S LONG 168' 17.6' E

ONE MINUTE OBSERVATIONS & PREDICTIONS TO 20:01 02 APR 2007 UTC

FIRE

BS

20 21 22 23 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21

01 April 2007 02 April 2007

PORT VILA, EFATE, VANUATU - LAST 24 HOURSLAT 17 45.7' S LONG 168 17.6' E

ONE MINUTE RESIDUALS TO 20:01 02 APR 2007 UTC

{

-0.5

20 21 22 23 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21

01 April 2007 02 April 2007

Figure A2 -7: Tide gauge recording at Port Vila for 2 April 2007 tsunami (a) tide and tsunami signal (b)tsunami signal with predicted tide removed (Source ABoM, 2007)


[57]

(ii) September 2007 Santa Cruz Tsunami Bulletins

The Santa Cruz earthquake 7.4Mw 2 September 2007, was within the range 6.5 -7.5Mw andthe bulletin (rather than warning) produced by the PTWC advised of the potential for a Local(see A2 -4 (i)) Tsunami within 100km. The distances to Honiara and Port Villa were greater than100km and travel estimated travel times greater than 1 hour. The Port Vila tide gauge recorded4 cm amplitude (8cm peak -to- trough)..

TSUNAMI BULLETIN NUMBER 001PACIFIC TSUNAMI WARNING CENTER/NOAA /NWSISSUED AT 0121Z 02 SEP 2007

THIS BULLETIN APPLIES TO AREAS WITHIN AND BORDERING THE PACIFICOCEAN AND ADJACENT SEAS...EXCEPT ALASKA...BRITISH COLUMBIA...WASHINGTON...OREGON AND CALIFORNIA.

... TSUNAMI INFORMATION BULLETIN ...

THIS BULLETIN IS FOR INFORMATION ONLY.

THIS BULLETIN IS ISSUED AS ADVICE TO GOVERNMENT AGENCIES. ONLYNATIONAL AND LOCAL GOVERNMENT AGENCIES HAVE THE AUTHORITY TO MAKEDECISIONS REGARDING THE OFFICIAL STATE OF ALERT IN THEIR AREA ANDANY ACTIONS TO BE TAKEN IN RESPONSE.


ORIGIN TIME - 0105Z 02 SEP 2007COORDINATES - 11.8 SOUTH 166.0 EASTDEPTH - SHALLOWER THAN 100 KMLOCATION - SANTA CRUZ ISLANDSMAGNITUDE - 7.4

EVALUATION

NO DESTRUCTIVE WIDESPREAD TSUNAMI THREAT EXISTS BASED ONHISTORICAL EARTHQUAKE AND TSUNAMI DATA.

HOWEVER - EARTHQUAKES OF THIS SIZE SOMETIMES GENERATE LOCALTSUNAMI THAT CAN BE DESTRUCTIVE ALONG COASTS LOCATED WITHINA HUNDRED KILOMETERS OF THE EARTHQUAKE EPICENTER. AUTHORITIESIN THE REGION OF THE EPICENTER SHOULD BE AWARE OF THISPOSSIBILITY AND TAKE APPROPRIATE ACTION.

THIS WILL BE THE ONLY BULLETIN ISSUED FOR THIS EVENT UNLESSADDITIONAL INFORMATION BECOMES AVAILABLE.

THE WEST COAST /ALASKA TSUNAMI WARNING CENTER WILL ISSUE PRODUCTSFOR ALASKA...BRITISH COLUMBIA... WASHINGTON ...OREGON...CALIFORNIA.








[58]

ORIGIN TIME - 0105Z 02 SEP 2007COORDINATES - 11.8 SOUTH 166.0 EASTDEPTH - SHALLOWER THAN 100 KMLOCATION - SANTA CRUZ ISLANDSMAGNITUDE - 7.3 (NOTE THIS IS REDUCED FROM 7.4)

EVALUATION

FURTHER SEISMIC ANALYSIS INDICATES THAT THIS EARTHQUAKE MAYBE THE KIND OF EARTHQUAKE THAT RUPTURES MORE SLOWLY AND HAS ANINCREASED POTENTIAL TO GENERATE TSUNAMI WAVES THAT COULD BEDAMAGING NEAR THE EPICENTER. THIS CENTER WILL CONTINUETO MONITOR NEARBY SEA LEVEL GAUGES AND WILL REPORT ANYTSUNAMI WAVES THAT ARE OBSERVED.

THIS WILL BE THE FINAL BULLETIN ISSUED FOR THIS EVENT UNLESSADDITIONAL INFORMATION BECOMES AVAILABLE.

THE WEST COAST /ALASKA TSUNAMI WARNING CENTER WILL ISSUE PRODUCTSFOR ALASKA...BRITISH COLUMBIA... WASHINGTON ...OREGON...CALIFORNIA.







ORIGIN TIME - 0105Z 02 SEP 2007COORDINATES - 11.8 SOUTH 166.0 EASTDEPTH - 33 KMLOCATION - SANTA CRUZ ISLANDSMAGNITUDE - 7.3


GAUGE LOCATION LAT LON TIME AMPL PER

VANUATU VU 17.85 168.3E 0339Z 0.04M / 0.1FT 26MIN

LAT - LATITUDE (N- NORTH, S- SOUTH)LON - LONGITUDE (E -EAST, W -WEST)TIME - TIME OF THE MEASUREMENT (Z IS UTC IS GREENWICH TIME)AMPL - TSUNAMI AMPLITUDE MEASURED RELATIVE TO NORMAL SEA LEVEL.

IT IS ...NOT... CREST -TO- TROUGH WAVE HEIGHT.VALUES ARE GIVEN IN BOTH METERS(M) AND FEET(FT).

PER - PERIOD OF TIME IN MINUTES(MIN) FROM ONE WAVE TO THE NEXT.

EVALUATION

SEA LEVEL READINGS INDICATE A TSUNAMI WAS GENERATED. IT MAY HAVEBEEN DESTRUCTIVE ALONG COASTS NEAR THE EARTHQUAKE EPICENTER. FORTHOSE AREAS - WHEN NO MAJOR WAVES ARE OBSERVED FOR TWO HOURSAFTER THE ESTIMATED TIME OF ARRIVAL OR DAMAGING WAVES HAVE NOTOCCURRED FOR AT LEAST TWO HOURS THEN LOCAL AUTHORITIES CAN ASSUMETHE THREAT IS PASSED. DANGER TO BOATS AND COASTAL STRUCTURES CANCONTINUE FOR SEVERAL HOURS DUE TO THE CONTINUING SEA LEVELCHANGES AND RAPID CURRENTS. AS LOCAL CONDITIONS CAN CAUSE A WIDEVARIATION IN TSUNAMI WAVE ACTION THE ALL CLEAR DETERMINATION MUSTBE MADE BY LOCAL AUTHORITIES.

NO TSUNAMI THREAT EXISTS FOR OTHER COASTAL AREAS IN THE PACIFICALTHOUGH SOME OTHER AREAS MAY EXPERIENCE SMALL NON -DESTRUCTIVESEA LEVEL CHANGES LASTING UP TO SEVERAL HOURS.


[59]

3 Tsunami Warning Related Background

(i) Summary of JMA /PTWC causal earthquake criteria

Table A2 -3: JMA and PTWC use simple criteria based on magnitude of the earthquake as a quickapproximate assessment of an earthquakes potential to generate Local, Regional and Ocean -wideTsunami ( Pearce, 2006).

Magnitude (Mw)if less than 100km deep

PTWC & JMA Bulletin /WarningMw and depth may change in first hourAmplitude for Destructive Tsunami > 0 .5 m

6.5 to 7.5Potential for a Locally destructive tsunamiwithin 1 hr (100km)

7.6 to 7.8

Potential for a Regionally destructivetsunami within 3 hr (1000km )

7.9 and abovePotential for an Ocean Wide destructivetsunami

Table A2 -3 provides a summary of the simple criteria, based on magnitude, from PTWC /JMAand ATAS, used as a first approximation of an earthquake's potential to produce a local,regional or ocean -wide tsunami. Maximum tsunami wave height is more directly proportional tothe vertical displacement of the rupture; however as magnitude can generally be determinedwithin 10 -15 minutes, it is used in the waarning process to provide a quick approximation.Thevertical displacement takes considerably longer and is more difficult to estistimate.

If an earthquake is deeper than 100km in the Earth's crust, no tsunami will be generated. Anevent in the range 6.5 to 7.5 Mw could produce a locally destructive tsunami affecting an areawithin 100 km or 1 hour's travel time. An event between 7.6 to 7.9 Mw could produce aregionally destructive tsunami affecting an area within 1000 km or 3 hrs travel time. Anything7.9 Mw and above has the potential to produce an ocean -wide destructive tsunami. The PTWC& JMA also use the criteria, equal to or greater than 0.5 m amplitude as the definition of adestructive tsunami.

The PTWC Bulletins are issued as advice to government agencies. Only national and localgovernment agencies have the authority to make decisions regarding the official state of alert intheir area and any actions to be taken in response. All PTWC warnings and travel -times are inUTC (equivalent Z and GMT).

It is a national responsibility to provide public information; e.g. expected time of arrival in local &UTC time, recorded heights, the need to wait approx 2 -3 hours from expected or actual time ofarrival for all clear.


[60]

(ii) Tsunami hazard sourcesThe source of historical earthquake generated tsunami events around the Pacific is shown inFigure A2 -8 and Figure A2 -9 shows the time it would take a tsunami from any location to reachHoniara (i.e. inverse Tsunami Travel Time).

Figure A2 -8: Historical Tsunami Events in the Pacific and Eastern Indian Ocean. Circle size indicatesearthquake magnitude and colour indicates tsunami intensity (SPSLCMP Pacific Country Report, June2005).

Figure A2 -9: Inverse Tsunami Travel Times (hours) for Solomon Islands Capital, Honiara. (SPSLCMPPacific Country Report, June 2006).


[61]

(iii) Real -Time Sea level data available for Tsunami monitoring

The Solomon Island sea level monitoring gauge at Honiara was installed in 1974 by Universityof Hawai'i. After the Banda Ache Tsunami in 2004, semi real -time data communications wasinstalled by ABoM allowing access to 10 minute updates of 1 minute data.

Real -time sea level data for monitoring tsunami in the Pacific is available from other Pacific sealevel monitoring gauges to all National Meteorological Agencies through the WorldMeteorological Organisations (WMO) global telecommunications system (GTS) network.Software is available from the IOC to decode and display this data. SOPAC is looking at arange of options for making this data and the analysis tools available to PICs.

Currently most Pacific island countries access even their own data through web services suchas University of Hawai'i (Figure A2 -10) and Australian Bureau of Meteorology (ABoM) (FigureA2 -11 and Table A2 -4).

Most of these gauges are in lagoons or harbours and readings will include a range of additionalaffects such as shoaling and seiching as well as other background noise which can make ithard to distinguish a small tsunami signal. Tidal information to compliment that can complementTsunami warning arrival times is available at:http: / /www.bom.gov.au /oceanography /tides /MAPS /pac.shtml.

NOAA Dart Buoy network data (Figure A2 -12) is available in semi real -time throughhttp : / /www.ndbc.noaa.gov /dart.shtml these gauges are in deep water (about 3000 m) and arenot affected by shoaling or seiching.

Unfortunately, it is not possible to locate the current type of DART buoy too close to a Trench,such as between the Solomon' s Trench and the Solomon Islands, due to the effects of theseismic signal overpowering the tsunami wave signal. Therefore there would be little chance ofconfirming a tsunami has been generated by an earthquake from the Solomons Trench before itreached parts of the Solomon Islands. However the gauges on the University of Hawai'i webpage are useful for early warning for the northwest sources.

Figure A2 -10: Location of University of Hawai'i real -time sea level sites( http: / /uhslc.soest .hawaii.edu /uhslc /data.html).


o'-

-1o' -

[62]

-2a'-

FSM

Nauru

Marshall Islands

Kiribati

Solomon Islands Tuvalu

VanuatuFiji

Samoa

Cook IslandsTonga

ao'-

1 3 0 ' ' 15 16 170' 20ä 210'

Figure A2 -11: Locations of Australia's seaframe tide gauge network for Southwest Pacific. This networkis also used for tsunami monitoring (Warne 2007).

Table A2 -4: List of seaframe gauges in Pacific and update frequency available for monitoring tsunami.The update frequency of the Pacific array is in the process of being upgraded to 10min updates.

r Port NumbersI

NOAA ARRAY

ATT [GLOSS L11-11 Station name

4428 03 115 [Colombo, Sn Lanka

480 r 12 ISiboIga, Sumatera, SW Coast

8815 119 I 008 !Yap. Caroline Island, FSM, Pacific Océan

680 120 007 rMalakal, Belau, Pacific Qcean

Position

Latitude Longitude

116° 56 54" N 079' 51' 1Z E

0.1 °4a'N 098 °46'E

09° 30' 30" N 138° DT 42" E

D7°19' 48" N 1 134° 27' 48" E

(Access Update PDF Plots

[ethod Frequency 7 day 7 day

1`1-.S 115 Minutes 1 -min 1 -min

GTS 115 Minutes 1-rnin !{Hirt

1 GTS 115 Minutes 1 -min 1 -min

TS 15 Minutes 1 -min 1 -min

1 Port Handlers 1 PACIFIC ARRAY

A.-FF-1- GLOSS UHLC I Stall an name13-1-1-410D 1Lombrum. Manus Island, Papua New Guinea

r56û7 Iâ6 1109 !Honiara, Guadalcanal, Solomon Islands

5732 r 115 !Part Vila, Efate, Vanuatu

6518 r 4 -03 !Jackson Bay, South Island, New Zealand

5598 139 ß23 Avatiu, Rarotonga. Cook Islands

6óe r 938 INuku álofa; Tongatapu, Tonga

584 r 401 !Apia, Upolu, Samoa

7q5 722 018 !cuva Viti Levu. Fiji

6707 r 452 1Lautoka, Viti Levu, Fiji

16744 I 121 1 025 IFongafale, Funafuti, Tuvalu

879 113 eel (Betio, Tarawa, Kiribati

7ûA 114 054 1Aiwo, Nauru. Nauru

6758 112 ßD5 Uliga, Majuro. Marshall Islands

75 115 0111 IDekehtik, Pohnpei, FSM

1

Position Accu Update. I PDF Plats

Latitude 1 Longitude Method Frequency 1 day 7 day

112° 02' 31.5" S 147° 22' 25.6' E [MSS RD Minutes 1 -min 1 -min

119° 25'44.1" 5.1159° 5T 19.3" E GMS Hourly &min ûmin

17° 45' 19.2" S 168° IF 27.T' E CMSS 10 Minutes 1{nin 1nin43° 58' 222" S 168° 36' 5ß_p' E GMS Hourly 6-min 6 -min

F21°1217.1' S 159° 4T 52' W GMS Hourly r -min rFrmin

21° D8' 12.5" S 175° 10'50.5" W CMSS 10 minute 1 -min 1 -min

13° 49' 36.4" S 171' 45'40.7' W CMSS 10 minute

78°08'3.1 "S .178 °25'24.8 "E CM55 10 minute 1 -min .1 -min

17` 3û' 17.T' S 1177° 2617.7 E [MSS 10 minute I1 -min 1 -min

08 °30'8.9 "S 1179 °11'42.6 E.1CMSS 10 minute 1 -min 1 -min

01° 21' 54,2" N1112° 55.58.8" E GMS Hóurly menin 5 -min

119 °31'45.9 "S1166 °54'36.2'E GMS Hourly 6 -min.6 -min

07° 06' 21.T' N 171° 2Z 22.1" E GP/IS Hourly T -min 6 -min

e6° 58' 49.9" N 1 158° 1Z 0.8" E CMSS 1f minute 1 -nun 1 -min


[63]

DART LOCATIONSMarch 2007

105.0E 1350E 1135 OE 135 OW

AfJT,..ti .'*

.

ykJte

P -P acilic

*Clik,n DART

Planned Cliileon

pJaonnYCldle,yn

fiPóiunedChikan 45 GS

Completed 1 281 *

Palled 1111 *Tolal R elvrco k 1391

Figure A2 -12: Locations of Deep ocean tsunami monitoring buoy network.


[64]

APPENDIX 3

Additional Modelling

1 Modelling of major tsunami for sources around the Pacific

The deep -water modelling for the 39 magnitude 9 tsunami sources around the Pacific, used inthe composite in Section 4, are shown in Figure A3 -1. Note that the main energy is beamedperpendicular to the trench and then channelled by bathymetry. The Solomons Trench sourceFigures A3 -1 (31, 32, 33 & 34) are the most critical for Solomon Islands..

1

120' 140' 160' 180' 200' 220' 240' 280' 280' 300'

60' 60'

40'

20

-20'

-40

40

20

o

-20'

-40'

-60'12.0' 140

00

160 16o. 200'60'

220 240' 260' 280' 300'm

0.1 0-2 0.3 0.4 0 -5 2 0.0 0.1 0.2 0.3 04 0.5

120 1,0 1613- 160- 200' 220' 240' 26o. 280

60 - - i iLi 60

0/4r

-60 I - - - . -CO'

120 140 160' 180 200 220' 240' 260 2817' 300

40 -0 0-1 0.2 0.3 0 -4 0.5

60'

40'

20'

o-

-20'

-40'

120' 140' 180' 160' 200' 220 240' 200' 280' 300'

60-

40

20-

-e0' : -60'1217' 140 160' i80 200' 220- 240' 260' 280' 300'

5 0.0 0.1 0.2 013 OA 0.5 6

120' 140 160 180- 200' 220' 240' 260' 280-

60'

160' 160 200' 220' 240' 260' 280'm

00 0.1 0.2 0.3 0.4 0.5

300'


[65]

120'

80'

140 180 180. 200 220' 240' 260_260' 300'

- 60

40'

20'

so. _60.

120' 140 169 180 200 220' 240' 259' 280' 300'm

7 0.0 0.1 0.2 0.3 0.4 0.5

9

220' 240' 260 260' 300

11

120' 140" 160' 180' 200 220" 240' 260' 280' 300'Im

9.0 0"1 02 0.3 0:4 0"5

120' 140 160' 180" 200' 220' 240' 260' 280' 300

40'

20

0'

-40'

120' 140' 180' 160 200' 220' 240' 280

8 0.0 0.1 0.2 013 0.4

120' 146' 160' 180 200' 226Y 240 260

10

60'

40'

a

280' 300'Fri

0.5

280 300

fio ¡ - . i A 60'

40

20'

0

-40

.

120' 140 150 180 200' 220' 240 260 280

0.0 0.1 0.2 0.3 0.4

m0.5

180' 260' 220' 240' 260' 290'

49'

20'

0

-60.300'

300'

0.1 0.2 0.3 0.4 05

13

120' 140 160' 160 200 220' 240 260' 280 300

40'

20'

90'

40'

20'

0

-40

.120' 140' 160' 180' 200' 220' 240 280. 280' 300'

I m0.0 0.1 02 0.3 0A 0.5

14

120. 140- 160- 180

60

4

200 220. 240' 260 280' 300'

60

-20'

-4

-60120' 140 160' 160' 200' 220' 249' 260 20.7 360'Mr m

0.0 01 02 0.3 03 05


[66]

120. 14o. 1 s 1943 200' 220' 240' 2s0. 2s0 390s20 140' 160 180 200' 220' 240' 26o' 280' 3ao

fio

4e

2a

0'

-40'

-60120'

- ".

r

! !rr-

t,, .}e

.[

-

140' 160 180' 200 220 290' 26o 280 300'

so

ao

20

-ae'

so

-20

40'

-60

ps0

w

w-ap'

.. - I7

' . -20'

y t 40

4. -60'

120

15

140' 160' t80' 200' 220 240 260" 280' 300'm 16

1 m

0"0 0.1 0.2 0.3 0.9 0.50.0 0.1 02 0.3 0.4 0"5

120 190 160' 180 200' 220' 240' 260' 280' 300'_

120' 140' 160 180' 200' 220' 240' 260' 280' 300

60

40'

2 0'

20

120'

60

! .rT_

40

J

1

. S .

aa

0

-20

r1

-60'140 160 160' 200 220 240' 260' 260' 300'

60'

20

0"

-20'

-aO'

120

+1.;J

A rr' -. .

..,t

r I -r.,...- - - -

140' 160' 1N 200' 220' 240' 260 280 300

60' .

9°

20

8

_á°'

so

181m

0.0 0.1 0.2 0:3 0.4 0.517

I,- I m0.0 0"i 02 0.3 0.4 0"S

120' 140 160 480 200' 220' 240' 260' 280' 300'

1.".

20

-20

.i 60

wl r*-

a°

"

-!>,y fl

. . .

E

r

120

60

a

20

0

-20

4o

140' 160' t60' 200 220' 240' 260' 260' 300.

- r'

!ai- ._77'tt'' ., i

+.

.

80'

.20

o

-20.

-BO'120'

19

.140 160' 180' 200 220 240' 260 280' 300

120'

20

140' 160' 186' 200' 220' 240' 260' 280' 300'm

00 0.1 02 0.3 0.4 0.5 m00 0.1 03 0.3 0.4 0.5

120.

60

-20

4 0

-60'

140' 160' 180' 200" 220' 240' 260' 260' 300'... ... . _"

"

,i}r

N..

Z

',`.

i

60'

40-

-20'

-40'

-60'

120 140" 160' 160 200' 220 240 260' 280' 300'

60

40

20

p

0'

-40

i 604.... r1

. ..rr_

4p'

20

` 20'

y 1}_40'

-60'120 140' 16o' 160' 200' 220' 240' 260' 280 300'

120' 140' 160' 180' 200' 22o' 240' 260' 260 300' m

22 0.0 0.1 0.2 0"3 0.4 0"5m21 on 0.1 0.2 03 0.4 0.5


[67]

120' 140' 160 180' 200' 220' 240' 260' 280 300'

83 /^ - 80

A

20 20

-20

40'

_6o -so.120' 140' 160 180'

23 0.0 0.1

200' 220' 240 260

02 0 :3 0.4

280m

0.5

300'

123' 140' 180 180 230' 220' 240' 260' 280' 300'

60 1 r -lffi 60'

40

20

0

-20

-40"

40

20

0

120' 140' 160' 100' 200' 220' 240' 260' 280' 330'm

24 3.3 0.1 0.2 0.$ 0,4 0.5

120' 140' 160" 180 200' 220' 240 260 200 300'

so' t60'

40"

20'

0

J0'

4D'

20

0

- 20'

-40'

120' 140 160' 180 200 220 240 260 260' 300'Im

25 0.0 0.1 0,2 0.3 0.4 0.5

60'

40'

20'

-20'

-40

-60'

120' m nnn nano wn non. xnn

60

40

20'

0

-20'

-40'

120' 140' 160-60.

180' 200' 220' 240' 260 280 300'

26 0:0 0.1 0.2 0.3 0.4 0.5140 160' 160 204 220 240 260 260

27 0.0 0.1 0.2 0.3 0 "4

29

120 140' 160'

60

0 "5

0.1 02 0.3 D.4 0.5

160' 180' 200' 220' 240' 200' 280' 300'

28 0"0 0.1 02 0.3 0w 0.5


[68]

120' 140' 160' 180 200 220' 240' 260' 280' 300'

60'rji

' 60'

40

2

-2

40

-60'120'

31 0.0

- 60'260' 280' 300'

0.1 0.2 0.3 0.4 0.5 32

60'

-40'

20 140' 160 180' 200' 220' 240' 200' 280' 300

60

40

20

0'

- 20'

-40'

120' 140' 160 180' 200' 220' 240' 260' 280' 300'm

0.60.0 0.1 0.2 Si 0 "4

120" 140 160 180 200 220" 240 260' 280 300'T60

4

20

-2

40

-60'

120' 140' 160' 180' 200' 220' 240 260

33 0.0 0.1 0.2 0.3 0.4

60

40

20

-20'

280' 300'1m

0.5

4

120' 140' 160' 160 200' 220 240 269 280 30

60"

40

60

40'

120' 140 160 180" 200 220' 240' 260 280' 300'

60" " 60'

A

80' -

40'

20'

-20

40'

20'

0'

-40'

- 60'120' 140 160' 180' 200 220' 240' 260' 280' 300'

35 9.0 0 1 3.2 G.3 0.4 0.5

120 140 160 15.0' 200' 220

60'

4

2

-2

-40'

60'

40 200 260 300'

60"

120' 140' 160' 180 200' 220 240 260'

36 0.0 0.1 02 0.3

260!m

0.4 0"5

40'

20'

0

-20

-40'

-60300'

120 140 103 130 23.7 220 Zar 260' 280 300'

00 r 60'

d0

20'

0"

-40'

120' 140' 160 180

37 0.0

40'

20'

_20

-40'

_. -154Y

200' 220. 240' 260' 200' 300'im

0.1 0.2 0.3 0.4 0.538

120 140" 160' 160' 200 220


[69]

39

120' 140 160 180' 200 220 240' 260' 280 300"

BO'

40'

20'

-20

-40'

80'

40'

20

0

-20'

-40'

-80'120' 140' 160' 180 200' 220' 240' 260. 280' 300'

m0.0 0.7 02 0.2. 0.4 0.5

Figure A3 -1: Sources for 9Mw generated tsunami around the Pacific ( Thomas, personal comm. 2007)


[70]

2 MOST scenarios for sources affecting Solomon Islands

(i) Solomons Trench

MOST ( Method of Splitting Tsunami) Model scenarios for 9.0, 8.5 ,8.0 and 7.5 Mw potentialevents on the Solomons Trench are at Figure A3 -3. For events up to 8 Mw most of the energyis contained within the Solomon Islands or focused to SW. Above this magnitude, by virtue ofthe larger rupture area (Figure A3 -2), the energy is also focused to NE.

156` 158' 160°

Historical EarthquakesC 7 2007 Rupture Area ^ -6

Potential TriggeredEarthquakes

Mag 9 EarthquakeVolcanoes

',mermen'IKavrle&l .

100 km I939111

8°

-10

Figure A3 -2: Pink represents area ruptured during 2 April event. Grey the area that would need torupture to produce a Magnitude 9 generated tsunami event. (Cummins 2007)

,...... .,... . .

t..1's

a

. ''I

f

,. ,.. GI...ta

G _ :

+-p-Ç

,

r

.A .

:.,:t`

4

.

11.11..... - .1...."

.. ..

.p

j ~ .O^È

.

..r.,.....-- ....,. .ti.., ...... .,, .....- . ........ . .

--,,,-^,-q

£

.`.

1-s 1

.

--

..

..,.

..

r1}

- ...4. `y...

ÿ

q+dy ¡p'F S. r

,....-

Ir.

` °

'.

.

4

v1-,4-- A . -.

Figure A3 -3: Solomon Islands Trench most significant, with very short warning times (ABoM 2007)


[71]

(ii) New Hebrides Trench

The New Hebrides Trench to the south east of Solomon Islands has travel times of less than 2hours. Figure A3 -4 shows the 8.5 Mw, 8.0 Mw and 7.5 Mw model scenarios for the NewHebrides Trench.

.....n,. . ., >E .,..., .... 3.363, .,.Ifc.e1HUM .,,......,

#Ww . ,.,..., '4 7V

_,S.:p-_ ..

a.`f È% o - ÿ S

ÇjR

. ..

ei' 1

Il

-- y.131 ^ . .felsa.

t\ii , .,.

'- ,g.. r..r1..

.

...e

1 r7rc

°r s n.r .1 n ',d,

PAM a 17 Pa 11215113 141.931E Yy...sxc ..p. 1M i M

.16 - - wy.i y,l.

- ` +...}+.....

J°iii [l"4i. 4

,i rA'. .

i

Figure A3 -4: New Hebrides trench a critical source from SE with limited warning time (ABoM2007)


[72]

(iii) Mariana Trench

Tsunami events from the Mariana Trench to the NW would have longer travel times (4 -6 hours)to the Solomon Islands. Figure A3 -5 shows the 9 Mw and 8.5 Mw model scenarios.

A 1! I fl TS lB 1S ]A lG Y SI il F. NO 15i Na

Figure A3 -5: Mariana Trench a critical source from NW with approximately 4 hours lead time (ABoM2007)


Documents

SOPAC - WordPress.com · [3] TABLE OF CONTENTS ACKNOWLEDGEMENTS 4 ACRONYMS 4 1 INTRODUCTION 5 2 SOURCES OF TSUNAMI HAZARD 6 3 VULNERABILITY /EXPOSURE 8 4 OVERVIEW OF TSUNAMI HAZARD