Historical database in French Polynesia

1
Historical database in French Polynesia
Emile Okal Northwerstern University Evanston USA
Dominique Reymond CEA/DASE/Laboratoire de
Géophysique, Tahiti, Polynésie Française
2
Method

• Search in
• ITDB database (V. Gusiakov, Tsunami Lab.)
• Catalogues (Soloviev)
• Lab. archives
• Town council archives
• Old news-papers
• Publications
• Harvard CMT (for recent earthquake )
• In situ investigations with interviews of elderly
  people

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Some dates and number

• No report , but probable effects for 1819
  (Central Chile) and 1835 (South Chile), as these
  tsunamis were observed in Hawaii.
• Oldest report in French Polynesia 1837 (South
  Chile)
• Most frequent source-region Chile-Peru (1819,
  1835, 1837,1868, 1877, 1906, 1922, 1960, 1995,
  1996, 2001)
• Highest measured run-up 20 m in Marquesas for
  Aleutian 1946
• Most unknown history Tonga-Kermadec
• Minimal run-up in Polynesia atolls of Tuamotu
  Archipelago.
• First tide-gauge record 1958 (tsunami from
  Kuriles)
• First newspaper in Tahiti 1963

4
The oldest trace from archeological survey in
Hane, Ua Uka, Marquesas
C14 datations with sediments under a layer of
sterile sand, gives 1535lt date lt 1600
Candidates 1562 , oct. 28 (16 m run-up in
Central Chile) 1575 dec 16, Chile 1586 jul 9,
(26 m run-up in Peru) Tsunami in Peru Chile,
NGDC, 1985
JL. Candelot Te Taiko, Ouvrage, Marquises,
CTRP. M. KELLUM-OTINO, Archéologie dune
vallée des Marquises, SEO 26, Musée de lHomme,
Paris, 1971
5
Example Tsunami report from Marquesas 11 nov.
1922
16 nov. 1922
Arrival time 11 nov 7h00
4 meters
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Tahiti, newspaper Les Nouvelles , 29 mars 1964
Alaska
Map of Tahiti, Society Island, French Polynesia
Beware of newspapers Amplitude was gt 1 meter
The East-coast road ( Papenoo) after the tsunami
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Map of dangerous earthquakes in XIX cent.
jun 1896, Sanriku 4.5 m Haw
Aug 1868, 4.5 m Haw
Hawaii Isl.
May 1877, 4 m Marq
Marquesas
Apr 1819, Obs. Haw
1865, Tonga 1 m Marq
Feb 1835, Moderate dmg Haw
Nov 1837, 4 m Marq
undocumented
Marquesas only
Big in Poly. and documented
8
Dangerous earthquakes for Polynesia in XX cent.
Aleutian, 8.7 Mar 1957, 2-4 m Mrq
Kamchatka, 8.3 Nov 1952, 2-4 m feb 1923 undoc.
Aleutian, 8.5 1 avr 1946
Alaska, 9.2 Mar 1964, 2 m Mrq
Mexico, 8.1 Oct. 1995, 1m Mrq
Kuril, 8.2 oct. 1994, 1 m Mrq
Ecuador, Fev. 1996, 2-3 m Mrq
Peru, 7.3 Feb. 1996, 2-3 m Mrq
Peru, 8.4 jun. 2001, 0.9 m Mrq
30 Jul 1995, 8.0, 3-4 m Mrq
Tonga, 8.0 apr 1919, 1 m Haw
Chile, 11 nov 1922, 8.3 4 m Mrq
Chile, Aug 1906, 8.5 3.5 m Haw
May 1960, M 9.5
undocumented
Big in Marq
Big in Poly. and documented
9
Best measured run-ups in French Polynesia 1946
Apr. 1(Aleutian Isl.), post-survey of Emile Okal

• 54 new data points (6 Marquesan Islands, Easter
  Island and Juan Fernandez)
• 31 valleys of 8 Islands
• 48 interviews of witnesses aged (in 2000) 59 to
  89
• And also
• Tahiti, Society Island.
• Tubai , Rurutu Raivavae, Rurutu, Austral
  Islands.

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Hiva Oa et Nuku Hiva measured run-up of tsunami
1 Apr. 1946 (Okal al.) Most of these measures
are now in ITDB/Pac Tsu. Lab.)
Average run-up heights 6.6 /- 2.7 m In rivers
bed add up to 2 m
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Other observations cont.
Pitcairn
12
Field survey in Tahiti for tsunami 1946
3 waves 3 meters Inundation 300 m
Run-up 2 m ?? Inundation 200 m
Map of Tahiti
Faratea 2.5 m 2 houses destroyed
1 m Inundation 100 m
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Measured and reported run-up Apr 1, 1946, in
Tahiti
North-East coast 3 - 6m
Pointe Venus 2.6 m
Lafayette beach 2.65 m
Also, globally the west cost of Tahiti just
observed less than 1 meter (Report from Meteo.)
14
Other observations Austral Islands
Tubuai (Austral Isl.)
Rurutu
Raivavae
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Other observations
NE

• Tuamotu
• less than 1 meter
• Hao atoll 1.90 m (no damages)

VILLAGE
Rockstone , 1.90m height, completely flooded
OCEAN
Leeward Islands Raiatea, Tahaa and Bora Bora
0.50 to 0.75 m
Notice that for 2004 Big tsunami of Sumatra, it
was the same kind of effects for Maldivia about
2 meters (largely greater than the max altitude
of this country) And about 7- 8 meters in
Sri-Lanka at the same distance from the source
16
Tsunami Chile 22 may 1960 the protecting role
of coral reef
2 3 m !
1.5 - 2 m
1 m
1 m
From Vitoussek, BSSA
17
Tsunami of Chile 22 mai 1960 (continued)

• Rapa 1.5 m
• Raivavae 1.8 m
• Rikitea 1 m
• Iles sous le Vent ?
• Tuamotu
• Manihi lt 1 m or unseen
• Rangiroa
• Nihiru
• Taenga
• Takume
• Hikurearu
• Takaroa 1.8m of recession (?)

1 1.5 m
18
Takaroa
Vitoussek (BSSA vol 53, 1963), said The sea
level at the village is closer to the sea than
those of the lagoon
Village
19
The case of Tonga_Kermadec
Undocumented In Polynesia
0.9 m in Hilo (but not sure, arrival seems to
late, Okal et al. 2004 ) Undocumented In
Polynesia
2 meters in rarotonga 1 meter in
Marquesas Okal et al. 2004, found Mw 8.3
Okal, E.A., J. Borrero, et C.E. Synolakis, The
earthquake and tsunami of 1856 November 17
evidence for far-field tsunami hazard from Tonga,
Gephysical Journal International, 157, 164-174,
2004
20
H. Hébert, F. Schindelé, Modélisations des
inondations pour l'aéroport de Tahiti-Faaa, 2005

21
International Tahiti-airport numerical
simulations of flooding with a tsunami generated
by a Mw8.0 magnitude in Tonga
Water thickness 30 to 60 cm on the average, and
very locally 1 m
Flooding at 3h30
Flooding at 4h30
CEA/DASE H.Hebert al.
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Conclusions (1)

• New reports have been found
• Probably Peru 1586 jul 9
• Chile Nov 1922
• Chilean tsunami Nov 1837, May 1877
• Database for Aleutian 1946 completed
• New measures and reports Aleutian 1952,1957, and
  Alaska 1964.
• Incorporation of measures in our database for
• Chilean tsunami Nov 1837, May 1877
• And also complete catalogue of small tsunamis
  recorded has been updated (44
• But, no progress on knowledge on Tonga-Kermadec
  historical earthquakes , except with simulations !

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Conclusion (2)

• Minimum level of source size for transoceanic
  Tsunami 8.7
• Exception Marquesas (as low as 7.3 !)
• Regionalization of risk levels
• Tuamotu , Leeward Isl. (lowest level)
• Tahiti, Austral Isl.
• Marquesas (largest level)
• Confirmation of tsunami warning threshold
• 7.0 for Marquesas for South America region
• 8.7 for trans-Pacific tsunami

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Tsunami amplitude estimation in Papeete
harbourvs Mantle magnitude Mm
Peak-to-peak amplitude in m
Alerte rouge
Pas dalerte pour Tahiti
Warning for Marquesas
Red warning
25
Quelques observations de tsunamisen haut
tsunami du Chili, 30 juillet 1995 (mag. 8.0) à
Hiva Oaen bas Aléoutiennes, 9 mars 1957 1er
avril 1946 (mag. 8.5) à Hawaï
CEA/DASE/LDG_Tahiti
1 Avril 1946 Hilo - Hawaii
9 mars 1957 Oahu - Hawaii
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Ua Pou and Ua Huka measured run-up of tsunami 1
Apr. 1946 (Okal al.)
Ua Pou