Geoinformation for Disaster and Risk Management - ISPRS

Indian Ocean Tsunami Impact on Northwest
Sumatra Coast
The tsunami generated by the great Sumatra
earthquake of 26 December 2004 devastated 200
kilometers of Sumatra coast from Kuede on the north
end of the island to south of Meulaboh on the west
coast. Of the roughly 223,000 lives lost during this
event, 72% of the casualties were caused by the
near-field tsunami that struck northern Sumatra; the
remaining deaths were due to the far-field tsunami
that impacted coasts around much of the Indian
Ocean. Post-tsunami reconnaissance surveys of the
northwest coast of Sumatra indicate tsunami flow
depths of five to 12 meters along the north coast and
seven to 20 meters along the west coast; peak run-up
was as high as 39 meters west of Aceh Province near
Lhoknga.
The image pair below illustrates a small portion of
the Landsat scene which has experienced extensive
destruction along coastlines, river channels, and
estuaries. The large affected area, toward the center
of the scene on the right, shows inland intrusion by
the tsunami of greater than 3 kilometers. Upland
areas, above 15-20 meters, were largely unaffected.
Studying these flow depths and run-up heights show
that the tsunami may have had alternate sources,
such as secondary intraplate faults, contributing to
the tsunami in addition to interpolate slip on the
Sumatra megathrust. Understanding this means that
tsunami warning times for inhabitants are reduced
and there is an increased likelihood of devastation by
inundation.
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Landsat Comparison of Pre/Post
Tsunami Acquisitions for the
Northwest Sumatra Coast