Age estimates of coastal terraces in the Andaman and Nicobar Islands and their tectonic implications

Rajendran, Kusala and Rajendran, CP and Earnest, Anil and Prasad, Ravi GV and Dutta, K and Ray, DK and Anu, R (2008) Age estimates of coastal terraces in the Andaman and Nicobar Islands and their tectonic implications. In: Tectonophysics, 455 (1-4). pp. 53-60.

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Abstract

The great Indian Ocean earthquake of December 26, 2004 caused significant vertical changes in its rupture zone. About 800 km of the rupture is along the Andaman and Nicobar Islands, which forms the outer arc ridge of the subduction zone. Coseismic deformation along the exposed land could be observed as uplift/subsidence. Here we analyze the morphological features along the coast of the Andaman and Nicobar Islands,in an effort to reconstruct the past tectonics, taking cues from the coseismic effects. We obtained radiocarbon dates from coastal terraces of the island belt and used them to compute uplift rates, which vary from 1.33 mm $yr^{-1}$ in the Little Andaman to 2.80 mm $yr^{-1}$ in South Andaman and 2.45 mm $yr^{-1}$ in the North Andaman. Our radiocarbon dates converge on \sim 600 yr and \sim 1000 yr old coastal uplifts, which we attribute to the level changes due to two major previous subduction earthquakes in the region.

Item Type:	Journal Article
Publication:	Tectonophysics
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Keywords:	Seismicity and tectonics;Subduction zones;Tsunami;Coastal terrace;Earthquake;Age dating.
Department/Centre:
Date Deposited:	28 Aug 2008 06:55
Last Modified:	19 Sep 2010 04:49
URI:	http://eprints.iisc.ac.in/id/eprint/15680

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