IASPEI - Picture Gallery

IUGG XXIV General Assembly July 2-13, 2007 Perugia, Italy
(S) - IASPEI - International Association of Seismology and Physics of the Earth's
Interior
JSS002 Poster presentation 1821
Tsunami Risk in the Northern Bay of Bengal
Dr. Phil Cummins
Geospatial and Earth Monitoring Division Geoscience Australia IASPEI
This presentation isa synthesis of the results of geologic and geodetic studies of the northern Bay of
Bengal, combined with an analysis of historical accounts of the 1762 Arakan earthquake and a
simulation of the tsunami that may have accompanied it. I show that these are all consistent with active
subduction in the Myanmar subduction zone, and hypothesize that the seismogenic zone associated
with it extends into the Bay of Bengal beneath the Bengal Fan. These results suggest that a very large
and vulnerable population is exposed to a high earthquake and tsunami risk. Other reports that have
characterised this hazard as low may have not considered the possibility that the seismogenic zone
extends offshore, as is suggested by GPS surveys, the active Bengal Fold System, and the historical
accounts of subsidence on the coast of Chittagong during the 1762 Arakan earthquake. Although
the2004 Indian Ocean Tsunami was difficult to foresee, some of the warning factors were there and
should have been recognized by the earth science community. This presentation attempts to draw
attention to similar warning factors in the Bay of Bengal, where the cost in human lives of a large
earthquake and tsunami may be much larger.