Crustal Deformation and Seismic History Associated with the 2004 Indian Ocean Earthquake: A Perspective from the Andaman–Nicobar Islands
IR@C-MMACS: CSIR-Centre for Mathematical Modelling and Computer Simulation, Bangalore
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Title |
Crustal Deformation and Seismic History Associated with the
2004 Indian Ocean Earthquake: A Perspective from the
Andaman–Nicobar Islands
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Creator |
Earnest, Anil
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Subject |
Global Positioning System
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Description |
The Indian Ocean earthquake of 26 December 2004 led to significant
ground deformation in the Andaman and Nicobar region, accounting for _800 km
of the rupture. Part of this article deals with coseismic changes along these islands,
observable from coastal morphology, biological indicators, and Global Positioning
System (GPS) data. Our studies indicate that the islands south of 10_ N latitude
coseismically subsided by 1–1.5 m, both on their eastern and western margins,
whereas those to the north showed a mixed response. The western margin of the
Middle Andaman emerged by _1 m, and the eastern margin submerged by the same
amount. In the North Andaman, both western and eastern margins emerged by _1m.
We also assess the pattern of long-term deformation (uplift/subsidence) and attempt
to reconstruct earthquake/tsunami history, with the available data. Geological evidence
for past submergence includes dead mangrove vegetation dating to 740 _
100 yr B.P., near Port Blair and peat layers at 2–4 m and 10–15 m depths observed
in core samples from nearby locations. Preliminary paleoseismological/tsunami evidence
from the Andaman and Nicobar region and from the east coast of India, suggest
at least one predecessor for the 2004 earthquake 900–1000 years ago. The history of
earthquakes, although incomplete at this stage, seems to imply that the 2004-type
earthquakes are infrequent and follow variable intervals.
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Publisher |
Bulletin of the Seismological Society of America
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Date |
2007-01
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Type |
Article
PeerReviewed |
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Format |
application/pdf
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Identifier |
http://cir.cmmacs.ernet.in/141/1/Bssa_2007.pdf
Earnest, Anil (2007) Crustal Deformation and Seismic History Associated with the 2004 Indian Ocean Earthquake: A Perspective from the Andaman–Nicobar Islands. Bulletin of the Seismological Society of America, 97 (1A). S174-S191. ISSN 0037-1106 |
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Relation |
http://www.bssaonline.org
http://cir.cmmacs.ernet.in/141/ |
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