Bathymetric survey of the submarine platformsaround the island of Vaté (Vanuatu)

Cruise RN IRD Alis NEOTECT

Benwd PEll..El1EAGuyCASIOQl

Julen PERRIERJearHllchel BORÉ

~====:_lS:':'''':'''::_:'''''''-.-'''-$ ,-"e-ne-,--:==;

RAPPORTS OE MISSIONS

SCIENCES DE LA TERRE

GEOLOGIE GEOPHYSIQUE

N° 41

2000

Bathymetric survey of the submarine platformsaround the island of Vate (Vanuatu)

Cruise RN IRD Alis NEOTECT

Benwd PEll..El1EAGuyCASIOQl

Julen PERRlEflJearHllchel BORE

~====:_lS:':'''':'''::_:'''''''-.-'''-$ ,-"e-ne-.--:==;

RAPPORTS OE MISSIONS

SCIENCES DE LA TERRE

GEOlOGIE GEOPHYSICUE

N° 41

2000

RAPPORTS DE MISSIONS

SCIENCES DE LA TERRE

GEOLOGIE GEOPHYSIQUE

W 41

2000

Bathymetric survey of the submarine platforms a.roundtile island of Vate (Vanuatu)

Cruise RN IRD Alis NEOTECT

• Bernard PELLETIER• Guy CABIOCH• Julien PERRIER

.. Jean-Michel BORE

• Centre IRD de Noumea, Nouvelle-Caledonie•• Antenne IRD de Port-Vlla, Vanuatu

== ..~ ......_-== ..~-.. -.. ....Institut de recherchepour le developpement

© IRD, Nouméa, 2000

/Pelletier, B./Cabioch, G./Perrier, J./Boré, J.-M.

Bathymetric survey of the submarine platforms around the island of Vaté (Vanuatu)Cruise RN IRD Alis NEOTECT

Nouméa: IRD. Février 2000. 40 p.Missions; Sei. Terre; Géol-Géophys. 41

CAMPAGNE OCEANOGRAPHIQUE; PALEOENVIRONNEMENT ; NIVEAU MARIN; RELIEF SOUS

MARIN; BATHYMETRIE; RECIF CORALLIEN; HOLOCENE / VANUATU; EFATE

Imprimé par la service de ReprographieCentre IRD de Nouméa

Février 2000

Bathymetrie survey of the submarine platforms around the islandof Vaté (Vanuatu)

Cruise R1V IRD Alis NEüTECT

Bernard Pelletier*, Guy Cabioch*, Julien Perrier* & Jean-Michel Boré**

* Centre IRD de Nouméa, Nouvelle-Calédonie** Antenne IRD de Port-Vila, Vanuatu

1 - Objectives

The cruise "Neotect" on the RJV IRD Alis was scheduled from 25 May to 3 June 1999to survey the shallowest areas, at a depth ranging from 0 ta 200 m, around the island of Vaté inthe south of the archipelago. The specifie objective of this cruise is to detect, in the bathymetryrecords, the paleo-sea level markers, i.e. submarine platforms or ancient reef flats, or ancientmarine notches, of the last 125 000 years (125 ka) (see sea level curve of the last 125 ka inBloom et al., 1974) especially the one belonging to the last glacial maximum (LGM) dated of 20ka (Bard et al., 1990) and corresponding to a low sea level stand at -120 m by comparison withthe modem sea level). If visible, the 20 000 years-old coral reef will constitute a key for thestudy of the uplif motions, between the 125 000 years-old and the Holocene coral reefs knownon land (Neef and Veeh, 1977, Jouannic et al., 1982, Lecolle et al., 1990).

This cruise was devoted to bathymetric measurements along lines orthogonal to the coastfrom 0 to 200 m. No soundings was done at night due ta the very shallow depths of thesurveyed areas. Sorne dredging was done depending on the results of bathymetry.

II - Technical informations

- NEOTECT Cruise, Efaté (Vanuatu), Resaerch Vessel IRD Alis, Capt Raymond PRONER.

- Scientific Team : Bernard Pelletier & Guy Cabioch (IRD Scientists, Nouméa), Julien Perrier(IRD technician, Nouméa) and Jean-Michel Boré (IRD technician, Port-Vila).

- Scientific survey : bathymetric survey and dredgings.

- IRD Research Unit 6.

III - Equipment

The bathymetric survey was realized using a FURUNO FCV echo sounder (frequency rangingfrom 28 kHz to 88 kHz) and a GPS MAGNAVOX giving the navigation. The ASCII data werestored in real time on a PC computer.

IV • Schedule of the cruise (see figure "schedule of the NEüTECT cruise" in "annexes")

25 May: departure: Nouméa

25-26 May: transit to Port-Vila

27 May: transit to Tukutuk Point and Devil Point

28 May : Tukutuk Point and transit to Port-Havannah

29 May: North-Moso and West-Moso

30 May : North N'Guna and East N'Guna

31 May: East and south coast of Vaté, Pango Point and arrivaI at Port-Vila

1 June: Devil Point

1-3 June: transit to Nouméa

3 June: arrivaI

V • Study areas &dredging operations

VI - 1 - Port-Vila to Devil Point and Tukutuk Point (see figures in "annexes")

TR 1 (from Port-Vila bay to Devil Point and Tukutuk Point) :from 17°45.1135, 168°10.455E to 17°41.0255, 168°10.313E

VI - 2 - Tukutuk Point (see figures in "annexes")

Box 1 (Tukutuk Point) : from 17°43.0115, 168°09.683E to 17°42.7895,168°08.897E

Dredging:D 1 (120 / 90 m)D 2 (130 / 150 m)D 3 (120 / 80 m)

TR 2 (from Tukutuk Point to Port-Havannah) : from 17°41.8165,168°08.897E to 17°36.2715. 168°14.584E

VI - 3 - Noth Moso and West Moso (see figures in "annexes")

TR 3 (from Port-Havannah to North Moso) : from 17°36.2495,168°14.578E to 17°32.0195, 168°12.948E

Box 2 (North Moso) : from 17°30.0075, 168°16.570E to 17°29.7225,168°16.476E

Box 3 (West Moso) : from 17°30.5945, 168°14.313E to 17°30.4175,168°13.957E

2

Dredging:D 4 (157 / 100 m)D 5 (123 / 90 m)D 6 (120 / 90 m)D 7 (117 / 90 m)

TR 4 (from West Moso to Port-Havannah) from 17°31.483S,168° 13.042E to 17°36. 162S, 168° 14.570E

VI - 4 - North N'Guna and East N'Guna (see figures in "annexes")

TR 5 (from Port-Havannah to North N'Guna) : from 17°36.162S,168° 14.570E to 17°25.002S, 168° 17.754E

Box 4 (North N'Guna) : from 17°25.002S, 168° 17.754E to 17°24.204S,168° 19.244E

Dredging:D 8 (125 / 102 m)D9(150/107m)

VI - 5 - Emao (see figures in "annexes")

TR 6 (from N'Guna to Emao) : from 17°24.204S, 168°19.244E to17°28.634S, 168°28.001E

Box 5 (West Emao) : from 17°28.634S, 168°28.001E to 1r28.926S,168°25.654E

Dredging:D 10 (125 / 102 m)D Il (150/ 107 m)

Box 6 (Mangea Reefs to North Emao)168°25.654E to 17°29.089S, 168°28.055E

from 17°28.926S,

VI - 6 - East and South coast of Efaté (see figures in "annexes")

TR 7 (from North Emao to Manuro Point): from 1r33.262S,168°3ü.436E to 17°42.514S. 168°36.420E

Box 7 (Manuro Point): from 17°42.512S, 168°36.24 lE to 1r43.260S,168°38.337E

TR 8 (from Manuro Point to Meslep Point) : from 1r43.260S,168°38.337E to 17°48.590S, 168°33.353E

TR 9 (vicinity of the Meslep Point) : from 17°48.590S, 168°33.353Eto 17°49.7üOS, 168°34.284E

TR 10 (from Meslep Point to Narpow Point) : from 1r49.700S,168°34.284E to 17°49.990S, 168°23.351E

TR 11 (vicinity of Narpow Point) : from 17°49.990S, 168°23.351E to17°51.448S, 168°23.282E

3

TR 12 (from Narpow Point to Pango Point) from 17°51.448S,168°23.282E to 1r46.845S, 168° 13.473E

VI . 7 - Pango Point (see figures in "annexes")

Box 8 (Pango Point) : from 17°46.845S, 168° 13.473E to 17°46.609S,168° 14.500E

TR 13 (from Pango Point to Port-Vila bay) : from lr46.609S,168°14.500E to 17°44.312S, 168°18.482E

VI . 8 - Devil Point (see figures in "annexes")

Box 9: from 17°44.252S, 168°18.504E to 17°45.082S, 168°1O.754E

Acknowledgments

We wish to thank the Vanuatu government and the "Service des Mines" for permits towork around Vaté and for their assistance. We would like also thank Michel Lardy (IRD,Port-Vila) for assistance in the cruise preparation and the crew of the RJV !RD Alis and itscaptain R. Proner

References

Bard E., Hamelin B., Fairbanks R.G. & Zindler A.(1990) Calibration of the 14C timescaleover the past 30,000 years using mass spectrometric U=Th ages from Barbados carals.Nature, 345 : 405-410.

Bloom AL, Broecker WS, Chappell JMA, Matthews RK, Mesolella KJ (1974) Quaternary sea­level fluctuations on a tectonic coast: new Th230 / U234 dates from the Huon Peninsula,New Guinea. Quatemary Research, 4: 185-205.

Jouannic c., Taylor F.W. & Bloom A.L. (1982) Sur la surrection et la défOlmation d'un arcjeune : l'arc des Nouvelles-Hébrides. In : Equipe de Géologie et de Géophysique:Contribution a l'étude géodynamique du Sud-Ouest Pacifique. Trav. Doc. ORSTOM, 147: 223-246.

Lecolle J., Bokilo J.E. & Bernat M. (1990) Soulèvement et tectonique de l'île d'Effaté(Vanuatu) arc insulaire des Nouvelles-Hébrides, au cours du Quaternaire récent. Datationsde terrasses soulevées par la méthode UlTh. Marine Ce%gy, 94 : 251-270.

Neef G. & Veeh H.H. (1977) Uranium series ages and late Quaternary uplift in the NewHebrides. Nature, 269 : 682-683.

4

ANNEXES

Schedule of the NEÛTECT crUIse

NEOTECT, R/V Alis, 1999

..

-17 0 30 1

1680

10'

1680

10' 1680

20 1

1680

30 1

1680

30'

1680 40 1

-17 0 30'

-170

401

_17 0 501

1680 40 1

Profiles of Tukutuk Point

Tukutuku Point, 1/25000, 5m

-170

43'

1680

09'-17 0 44'~__~~~~====- c::::========~_17 0 44'

1680

08'

-17" 43'

Profiles of North Moso

North Moso, 1/25000, 5m

-1T 29 1

---17" 29 1

· ..

Profils 1 ta 4 - North Maso

Cf} 0-17.495

Latitude

ID~ 20+-'

..................

Q) 40

.,

-17.500

E 60

.......

o Cf}

c... ....

20 ~

80

, .. ...

ID

3 2-

-

+-'

~ 100

-- 40 Q)

::J

60 E

Q) 120

1-....

-g 140

80 CQ)

o 160~

100 !oo.....

'+-

120 ::J

e 180

Q)

0... 200

140 "'0C

160 0

-17.495

'+-180 0

Latitude

!oo.....

-17.500200 0...

Profiles of West Moso

West Maso, 1/25000, 5m

1680

13'

-17 0 31'

Profils - West MasoCI)

Longitude(

ID 168.210 168.215 168.220 168.225 168.230 168.235 (~ 0 o l

CD 20 ...... ... ....... ... ... .f+.. c ~ i, .:5 L 4 20 ~E 40 40 1

60 ............................................•..•...... 60C 80 80ID 100 100~ 120 120:::J 140 140 .ID 160 160 ~

"'C 180 180 l

C 200 4 200 1

E 220 c- s 3 l 220 ~d-o 240 240 l~

168.220 168.225 168.230 168.235:

0... 168.210 168.215 (

Longitude

Profiles of North N'Guna

North Nguna, 1/25000, 5m

1680

19'

&

-170

24' -"1 T 24'

-1 T 25' L-. r:::===========.J_.-l -1 7 0 25'168

0

19'

Profiles of West Emao

_17 0 29'

_17 0 30'

West Emao, 1/25000, 5m

1680

26'

_17 0 29'

1680

26'

Profils 1 and 3 - West Emao

-17.475Latitude

-17.480 -17.485 -17.490o 0

20 ~~-~ 2040· .. -- . .. 40

Cf) 60 --------------.---------. -- --- ----------------- .. - ----------- - -............ . ----------------- - . . ------- --- - .. 60 Cf)(1.) 80 . - - -- --- . .. -- -.3 _____..1: 80 (1.)!...... _----00----- !......+J 100 100 +J(1.) 120-- . 120 (1.)E 140 -.,. ----- 140 E160------.-.-.... ..--- --- - - - - - -- -- -- 160

C C(1.) 180··.... 180 (1.)

200 .. . . 200!...... ...-!......$ ~~g . ..•..~........ .•••.••.••.•• ...•.. .. ~~g $

"'0 260 . 260 "'CC 280 280 Co 300 - -~ . . --- -- __ o. - ••• 300 0

*""' 320 320 *""'e 340 340 e0.. ~~g ~~. ..... ~~g 0..

400 ~ .~ . 400420 420

-17.475 -1 7.480 -17.485

Latitude-17.490

Profiles of South Emao

-17" 32'

-17" 3D'

-17" 31'

-17" 29'

168 0 29'1680

28'

. -'?i

~~t

i zn n-17" 33'168 0 3D'168

0

27'

, nil'.

/ /\., ,,: ~ \

/i :\ \~\./ ()

---~,{ \~. /i "'\'! .", \. ', .>'--... ""', / "-

~' ~~~~.,

...~,.

----x-

168 0 26'-17" 33 1

1680

25'

-17" 32'

-17" 3D'

-170

291

-17"31'

Profils 1 and 2 - South EmaoCf) Latitude Cf)

Q) -17.520 -17.525 -17.530 -17.535 -17.540 Q)~ ~

+-' 0 - O+-'Q) 20 20 Q)

E 40 -1.. 40 Ec 60 i 60 CQ) 80 ----'-'--"- ~. __. 80 Q)

100 100~ 120 120 ~:J 140 140 :J~ 160 160 {gC 180 180 Co2001, 4 200 0

'+- 220 220 '+-o 0~ -17.520 -17.525 -17.530 -17.535 -17.540 ~

Q. Latitude Q.

Profiles along East and South Vaté

Southeast Efate profiles

-170

45 1

-170

50 1

T/\n"'s,r(A 2.)

1680

25'

1680

25'

1680

30 1

1680

3D'

1680

35 1

1680

35'

East Efate - Manuro PointCf) Longitude Cf)

~ 168.605 168.610 168.615 168.620 168.625 168.630 168.635 ~....... 0 0 +-'

Q) 20 20 Q)

E 40 40 Ec 60 60 CQ) 80 80 Q)~ 100 ·v w. __ •• 100 ~::J 120 ....~.._-~-- 120 ::JQ.) 140 140 Q)'0 160 ~- ~ .._ , 160 "'0C 180 _.- ~.. 180 C0200 ~ 2000of- 220 220 *-e 168.605 168.610 168.615 168.620 168.625 168.630 168.635 eCL Longitude 0...

Cf)

a ~........,<JL)

50 Ec

100 <JL)

SE Efate, Meslep Point ta Manuro PointLongitude

168.60, 1l , ,

Cf) 168.55 "<JL) l ' ,'"- a........,<JL)

E 50

'"-C ~(1) 100 150 (1)

~ ~~ 150 200 C(1) 0~ -C 200 250 2o ~'+-

o 250 168.60~ .~ 168.55 Longitude

Southeast Efate - Meslep PointCf) Latitude Cf)

~ -17.810 -17.815 -17.820 -17.825 -17.830 ~~ 0 1 1 1 0 ~Q) 20 - f- 20 Q)E 40 - f- 40 Ec 60 - ----..... f- 60 CQ) 80 - --. . f- 80

100 - ------..-..... f- 100 Q)~ - ......- "'-::J 120 - .........~ f- 120 :::JQ) 140 - . ~_ 'f- 140 Q)"0 160 - ~__ f- 160 "0C 180 - --....._.-..., f- 180 Co 200 - ........"'--. f- 200 0o 220 1 1 1 220 0"'- -17.810 -17.815 -17.820 -17.825 -17.830 "'-

a.. Latitude 0..

..

South Efate, Narpow Point to Meslep Point

enLongitude

Cf)168.40 168.45 168.50 168.55Q) a ~!.... a+-' +-'Q) Q)

E 50 50 Ec cQ) 100 100 Q)

!.... !....

:::J 150 150 ::JID. Q)

"0 "'0C 200 200 C0 0*- *-o 250 250 0!.... !....

a... 168.40 168.45 168.50 168.55 a...Longitude

South Efate - Narpow PointCf) Latitude Cf)

~ -17.835 -17.840 -17.845 -17.850 -,17.855 ~of-' 0 0 -+-J

Q) 20 20 Q)

E 40 40 Ec 60 ~ 60 CQ) 80 ~~ 80 Q)~ 100 ..,.,....... 100 !o-

:::J 120 '--.._"......... 120 ::JQ) 140 '---..~ 140 Q)"'C 160 160 "0C 180 180 Co 200 200 0+- 220 220 '+-o 0!o- -17.835 -17.840 -17.845 -17.850 -17.855 !0-

n.. Latitude 0...

South Efate, Pango Point to Narpow PointCf) Longitude Cf)

Q) 168.25 168.30 168.35 Q)~ 50 50 ~Q) 100 100 Q)

E 150 150 EC 200 200 CQ) 250 250 Q)~ ~

~ 300 300 ~

Q) 350 350 Q)

"0 400 400 "0C Co 450 450 0

15 500 500 150= 168.25 168.30 168.35 0=Longitude

Profiles of Pango Point

·Pango Point, 1/25000, 5m

1680

14 1 1680

15'

-17°4T -17°4T

_17 0 48\~__============-_-=========~_170

48 1

1680

14' 1680

15'

- . ,. "' "1["

•

Profils - Pango PointLongitude

168.225 168.230 168.235 168.240 168.245 168.2500 0

20 2040 4060 60

Cf) 80 ... ..... . 80 Cf)

Q) 100 100 Q)~ ~

......., 120 120 .......,ID 140 ..r 140 Q)

E 160 160 EC 180 ...... .... .. 180 CQ) 200 ................ 200 Q)~ 220 1.- 220 ~

::::J 240 240 -ID 260 260 ::::J

"'C 280 280 ~C 300 300 Co 320 ..... -... 320 0

'+- 340 - ............ 340 '+-e360 360 ea.. 380 .. " ....... ....." .. - ... ". ....... 380 a..

400 ....... - .............. 400420 420440 440460 460

168.225 168.230 168.235 168.240 168.245 168.250

Longitude

1

Profiles of Devil Point

5000 5m-1 Point 1/2 ,DevI ,

170

46' 1680 10'

•

1680

11'046'-17

, -

Profils - devil Point'tJQS+ ~s+

Longitudeen en168.160 168.165 168.170 168.175 168.180 168.185 168.190Q)

0 o ~~

+-' 20 -...... 20 +-'Q) 40 Q)E 40 .....

60 60 Ec 80 0 80 CQ) 100 100 Q)~ 120 120 ~

::J 140 ....... ..••.• ·.H···· 140 ::JQ) 160 160 Q)o 180 "........ 180 "'0C 200 2- 200 Co 220 220 0o240

0240 '0... . .....•..• ....

~ ~

1- 168.160 168.165 168.170 168.175 168.180 168.185 168.190 0..Longitude

, .,..-

" 1· •

Profil 5 Devil PointenID~ sJ Latitude tJoJR ~

ID -17.760 -17.755 0 EE 0 ··s ~g C20 ~ . IDc 40 ..... 60(J) - .• ' 80 ...60 ~... 80 100 ID~ 100 120 "'0ID 120 .. 140 C"'0 .C 140 .Eo ·17.760 -17.755 eë Latitude D...~

0...

Centre IRD de NouméaB.P, AS Nouméa Cédex, 98848. Nouvelle-Calédonie© IRD2000

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