Report: Indian Ocean region vulnerable to massive tsunamis
COLOMBO: Sri Lanka and much of the Indian Ocean region
are vulnerable to as large or even larger tsunamis than the 2004 magnitude 9.2
Sumatra earthquake, a new study has warned.
The study on the frequency of past giant earthquakes
in the Indian Ocean region shows that Sri Lanka, and much of the Indian Ocean,
is affected by large tsunamis at highly variable intervals, from a few hundred
to more than one thousand years.
The findings suggest that the accumulation of stress
in the region could generate even larger tsunamis than the one that resulted
from the 2004 magnitude-9.2 Sumatra earthquake.
Researchers from the University of Miami (UM)
Rosenstiel School of Marine and Atmospheric Science and the University of
Peradeniya in Sri Lanka collected and analysed 22 sediment cores from Karagan
Lagoon, Hambantota in southeastern Sri Lanka, to expand the historical record
of giant earthquakes along the Sumatra-Andaman subduction zone, where the
India-Australian plate and Eurasian plate meet.
Using sand deposited in the lagoon during the 2004
Indian Ocean tsunami and seven older paleo-tsunami deposits as proxies for
large earthquakes in the region, the scientists reconstructed the timeline for
mega-earthquakes along the Indian Ocean's plate boundary from Myanmar to
Indonesia, assuming that the tsunamis were all generated by large earthquakes.
Survivors of the 2009 tsunami paying floral tributes
on a sand sculpture of a tsunami victim at Marina beach in Chennai. (File
“In Sri Lanka, coastal lagoons were inundated by this
tsunami and others that occurred over thousands of years,” said Gregor Eberli,
professor of Marine Geosciences and director of UM's CSL — Centre for Carbonate
“These lagoons are ideal repositories for tsunami sand
layers because after deposition, the tsunami sands were sealed with mud,” said
The December 26, 2004 magnitude-9.2 Sumatra earthquake
resulted in a transoceanic tsunami, with wave heights up to 100 feet in some
places, which impacted much of the Indian Ocean region, researchers said.
The resulting tsunami killed over 200,000 people in
fourteen countries, including India, and inundated coastal communities. (PTI)