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Models of tsunami waves at the Institute of Ocean Sciences
Josef Cherniawsky and Isaac Fine
Ocean Science Division, Fisheries & Oceans Canada, Sidney, BC
Port Alberni, March 27, 2014
Acknowledgements:
Richard Thomson Alexander Rabinovich
Kelin Wang Kim Conway Vasily Titov Jing Yang Li
Brian Bornhold Maxim Krassovski Fred Stephenson
Bill Crawford Pete Wills
Denny Sinnott … and others!
Our tsunami web site:
http://www.pac.dfo-mpo.gc.ca/science/oceans/tsunamis/index-eng.htm
… or just search for “DFO tsunami research”
An outline … o Introduction
o Models of submarine landslide tsunamis (4 min)
o A model of a Cascadia earthquake tsunami (4 min)
o Tsunami wave amplification in Alberni Inlet (4 min)
o A model of the 2012 Haida Gwaii tsunami (4 min)
o Questions
Examples of models of landslide generated tsunamis in Canada - some references -
Fine, I.V., Rabinovich, A.B., Thomson, R.E. and E.A. Kulikov. 2003. Numerical Modeling of Tsunami Generation by Submarine and Subaerial Landslides. In: Ahmet C. et al. [Eds.]. NATO Science Series, Underwater Ground Failures On Tsunami Generation, Modeling, Risk and Mitigation. Kluwer. 69-88.
Fine, I. V., A.B. Rabinovich, B. D. Bornhold, R.E. Thomson and E.A. Kulikov. 2005. The Grand Banks landslide-generated tsunami of November 18, 1929: Preliminary analysis and numerical modeling. Marine Geology. 215: 45-57.
Fine, I.V., Rabinovich, A.B., Thomson, R.E., and Kulikov, E.A., 2003. Numerical modeling of tsunami generation by submarine and subaerial landslides, in: Submarine Landslides and Tsunamis, edited by Yalciner, A.C., Pelinovsky, E.N., Synolakis, C.E., and Okal, E., NATO Adv. Series, Kluwer Acad. Publ., Dorderecht, pp 69–88. Rabinovich, A.B., Thomson, R.E., Bornhold, B.B., Fine, I.V. and E.A. Kulikov. 2003. Numerical modelling of tsunamis generated by hypothetical landslides in the Strait of Georgia, British Columbia. Pure appl. Geophys. 160: 1273-1313.
Thomson, R., Fine, I., Krassovski, M., Cherniawsky, J., Conway, K. and Wills, P., 2012. Numerical simulation of tsunamis generated by submarine slope failures in Douglas Channel, British Columbia. DFO Can. Sci. Advis. Sec. Res. Doc. 2012/115. v + 38p.
Hypothetical failure of the Fraser River delta front
Landslide-generated tsunami: sediments in Strait of Georgia
Rabinovich et al. 2003 Fine et al. 2003
Submarine Slide Tsunami
Time to cross the strait ~7 min
Richmond
Modeled wave heights for the case of a “Case 1” slide: area = 7.3 km2 volume = 0.75 km3
Waves up to 18 m high hit Galiano and Main Islands; less than 5 m on the mainland side.
Historic landslides
IOS models of earthquake generated tsunamis (some references)
Cherniawsky, J.Y., Titov, V.V., Wang, K. and J.-Y. Li. 2007. Numerical simulations of tsunami waves and currents for southern Vancouver Island from a Cascadia megathrust earthquake. Pure and Applied Geophysics. 164:465-492.
Cherniawsky, J.Y., 2007. Preliminary results from a project “Tsunami Modelling with Inundation: Sooke Harbour and Sooke Basin”. Unpublished Report for the Municipality of Sooke (can be requested from the author).
Fine, I., J.Y. Cherniawsky, A.B. Rabinovich and F. Stephenson. 2009. Numerical Modeling and Observations of Tsunami Waves in Alberni Inlet and Barkley Sound, British Columbia. Pure and Applied Geophysics. 165:1019-2044.
Titov, V.V. and Synolakis, C.E. (1997), Extreme inundation flows during the Hokkaido–Nansei–Oki tsunami, Geophys. Res. Lett. 24(11), 1315–1318. [nested-grid MOST model]
grid size ~ 900 m
An example of nested model grids grid size ~ 300 m
grid size ~ 50 m
Alberni Inlet
Some plausible sea-bottom uplift scenarios for a CSZ earthquake
Scenario A (Satake et al., JGR 2003; Wang et al., JGR 2003). Scenario B (Wang and He, BSSA 2008).
A B
Initial bottom deformation and wave propagation on a coarse
(900 m) grid
Scenario A
(Wang et al. 2003)
Cherniawsky et al. 2007
Scenario A without run-up (from CTWL2007) Scenario B with run-up
Maximum heights: Comparison of the two earthquake scenarios
Esquimalt and Victoria Harbours
Victoria Inner Harbour
Esquimalt Harbour
Victoria Esquimalt
Maximum wave height for 12 hour duration
4.2 m
Esquimalt
Victoria
Sea level time series at various sites
Time (min)
Time (min)
Site 5
Site 1
Maximum water speed Esquimalt Harbour Victoria Harbour
Outer Coast: Ucluelet Inlet and vicinity
Sea level time series at various sites
Itatsoo Bay
Ucluelet Inlet
Maximum water height Maximum water speed
1964 Great Alaska Earthquake tsunami waves travel times
(from NOAA web site)
Vancouver Island
Port Alberni tide gauge March 28-29, 1964
4 m
PST
1.7 hr
2.0 hr
Port Alberni tide gauge
Admittance functions for Bamfield and Port Alberni (relative to Tofino)
from power spectra of background sea-level oscillations
125.6W 125.4W 125.2W 125.0W 124.8W
48.8N
49.0N
49.2N
C1
C2C3
C5C4
Bamfield
Alberni
Spectral response method Numerical model details: Linear “flux” model (similar to a linear version of TUNAMI by Imamura) grid size: 40x40 m (1213x1223 grids) time step: 0.43 sec duration: 240 hours open boundary conditions: radiation + prescribed waves (from AR spectral function) Results processed using standard spectral analysis
0
2
4
6
8
10
12
14
16
Ampl
itude
Bamfield - Port Alberni response function
0 1 2 3Frequency (cph)
0100200
300400500600700
800900
Pha
se(d
egre
e)
DataModel
100 min 44 min
(from cross-spectra between Alberni and Bamfield)
The Haida Gwaii earth(sea)quake (from James et al. Eos 2013)
USGS finite fault model (G. Hayes 2012)
n NEIC hypocenter (Lon.=-132.1 deg.; Lat.=52.7 deg.). n Mw= 7.46e+27 dyne.cm n Nodal plane (strike=323.0 deg., dip=25.0 deg.). n Nx (along-strike)=18; dx=14 km n Ny (downdip)=10; dy=9 km n Oblique trust faulting
Correcting the USGS source position using inverse travel times to the 4 nearest DARTs
Isochrones: black – for tsunami arrival times (first rise ± 1 min); red – for 1st tsunami maximum Shadow zone: grey area
Source function (smoothed): thick yellow line – 10 cm contour; thick red – 100 cm contour (Fine et al. 2013a,b)
1000 m
Original Shifted
Initial surface deformation with its maximum on QCT (USGS/IOS source)
Nested grid tsunami model using the MOST3 code
Maximum sea level on a medium grid (~130 m grid size)
8.4 m
Tasu Sound
Gowgaia Bay
A revised uplift model based on GPS data (from Kelin Wang)
Hayes – Wang – Fine (HWF) Lay et al. – Wang – Fine (LWF)
Two possible initial deformation scenarios
(the last “seabed to sea surface” transformation was done as in Fine and Kulikov 2011)
from HWF source (coarse grid)
Maximum tsunami waves (HWF)
Seaquake/Davidson Inlet
Model bathymetry
Maximum tsunami wave and maximum speed (HWF)
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