Abstract:
At 00:58:53 UTC on 26 December 2004, a magnitude 9.0 earthquake occurred off
the west coast of Sumatra, Indonesia. This was the fourth largest earthquake in
the world since 1900 and the largest in over 40 years. It was caused by the
release of stresses in the Earth that are built up as the Indian tectonic plate
descends into the mantle beneath the Burma plate. It is estimated that the sea
floor
... was displaced several meters due to the quake, resulting in large ocean
waves, called "tsunamis" from the Japanese for "harbor waves." The tsunami
moved rapidly across the deep ocean, with speeds estimated around 640 km/hr.
When the waves reach shallow water near land, they slow considerably, but their
size increases dramatically and they strike with catastrophic force. With human
casualities exceeding 150,000, this event is one of the deadliest natural
disasters in modern history, causing devastation along the shores of Indonesia,
Sri Lanka, India, Thailand, and other countries.
The initial tsunami waves reached the eastern Indian coast around 3:35 UTC,
based on tide gauge measurements made at the port city of Vishakapatnam. The
Multi-angle Imaging SpectroRadiometer (MISR) aboard NASA's Terra satellite
passed over the eastern Indian coast between 5:10 to 5:20 UTC, when the tide
gauge indicated the arrival of another series of waves. Because MISR's nine
cameras imaged the coast over a time span of about 7 minutes, and because the
the waves are unusually large, MISR was able to capture unique time-lapse
imagery of the breaking waves. The still image shows four frames from the
instrument's backward-viewing cameras spanning a period of about 2.5 minutes.
This scene is located along the shores of Andhra Pradesh, near the mouth of the
Godavari River, and covers an area of 42 kilometers x 37 kilometers. The arrows
show the progression of the southwestern edges of the breakers.
An animated GIF is available at
http://eosweb.larc.nasa.gov/HPDOCS/misr/misr_html/tsunami_india.html
The Multi-angle Imaging SpectroRadiometer observes the daylit Earth
continuously and every 9 days views the entire globe between 82 degrees north
and 82 degrees south latitude. These data products were generated from a
portion of the imagery acquired during Terra orbit 26720 and utilize data from
within blocks 77 and 78 within World Reference System-2 path 142 (see Related
URL below for specific data files).
MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena,
CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is
managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division
of the California Institute of Technology. 
