HR: 1400h
AN: T43B-08 [Abstracts]
TI: A Millenium of Great, and Perhaps Lesser, Earthquakes Recorded by Unusual Landslide and
Tsunami Deposits in Chiloe, South-Central Chile
AU: * Cisternas, M
EM: marco.cisternas@ucv.cl
AF: Universidad Catolica de Valparaiso, Chile, Av. Brasil 2990, Valparaiso, Chile
AU: Lagos, M
EM: mlagoslo@uc.cl
AF: Universidad Catolica de Santiago, Campus San Joaquin s/n, Santiago, Chile
AU: Srinivasalu, S
EM: ponmozhisrini2001@yahoo.com
AF: Department of Geology, Anna University, India, Chennai-600 025, India, India
AB:
A stratigraphic sequence at Cocotue Bay, Chiloe Is., south-central Chile, containing both earthquake-triggered
debris flows and tsunami deposits, yields an earthquake history that likely includes the giant earthquakes and
tsunamis inferred previously from a combination of geology, ecology, and written records in south-central Chile
(AD ~1000, ~1300, 1575 and 1960).
However, the Cocotue sequence also contains evidence for at least four additional earthquakes and tsunamis
that are intermediate in age and perhaps lesser in size. The most recent of the additional earthquakes recorded
at Cocotue probably corresponds to the poorly understood Chilean earthquake and associated trans-Pacific
tsunami of 1837. The tsunami, though small on the Chilean coast, ran as high as 6 m in Hawaii and flooded
fields in Japan. At Cocotue, the 1837 earthquake, like other three earlier events, is probably represented by both
a debris-flow deposit and a tsunami deposit.
To study the sedimentary record of intermediate and lesser events is important because this is the more
probable kind of event to occur in the near future of south-central Chile.
Research funded by Proyecto Fondecyt 1060227
DE: 1817 Extreme events
DE: 3022 Marine sediments: processes and transport
DE: 4217 Coastal processes
DE: 7221 Paleoseismology (8036)
DE: 7240 Subduction zones (1207, 1219, 1240)
SC: Tectonophysics [T]
MN: 2007 Joint Assembly