Geodesy and Gravity/Tectonophysics
Uplift and subsidence associated with the great Aceh-Andaman earthquake of 2004
Article first published online: 15 FEB 2006
Copyright 2006 by the American Geophysical Union.
Journal of Geophysical Research: Solid Earth (1978–2012)
Volume 111, Issue B2, February 2006
How to Cite
2006), Uplift and subsidence associated with the great Aceh-Andaman earthquake of 2004, J. Geophys. Res., 111, B02407, doi:10.1029/2005JB003891., , , , , , and (
- Issue published online: 15 FEB 2006
- Article first published online: 15 FEB 2006
- Manuscript Accepted: 22 NOV 2005
- Manuscript Revised: 5 OCT 2005
- Manuscript Received: 20 JUN 2005
- satellite imagery;
- coral reef;
 Rupture of the Sunda megathrust on 26 December 2004 produced broad regions of uplift and subsidence. We define the pivot line separating these regions as a first step in defining the lateral extent and the downdip limit of rupture during that great Mw ≈ 9.2 earthquake. In the region of the Andaman and Nicobar islands we rely exclusively on the interpretation of satellite imagery and a tidal model. At the southern limit of the great rupture we rely principally on field measurements of emerged coral microatolls. Uplift extends from the middle of Simeulue Island, Sumatra, at ∼2.5°N, to Preparis Island, Myanmar (Burma), at ∼14.9°N. Thus the rupture is ∼1600 km long. The distance from the pivot line to the trench varies appreciably. The northern and western Andaman Islands rose, whereas the southern and eastern portion of the islands subsided. The Nicobar Islands and the west coast of Aceh province, Sumatra, subsided. Tilt at the southern end of the rupture is steep; the distance from 1.5 m of uplift to the pivot line is just 60 km. Our method of using satellite imagery to recognize changes in elevation relative to sea surface height and of using a tidal model to place quantitative bounds on coseismic uplift or subsidence is a novel approach that can be adapted to other forms of remote sensing and can be applied to other subduction zones in tropical regions.