HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (21) Citing Articles via Google Scholar Google Scholar Articles by Zachariasen, J. Articles by Hantoro, W. S. Search for Related Content GeoRef GeoRef Citation

Modern Vertical Deformation above the Sumatran Subduction Zone: Paleogeodetic Insights from Coral Microatolls

Seismological Laboratory
California Institute of Technology
Pasadena, California, 91125
(J. Z., K. S.)

Institute for Geophysics
University of Texas at Austin
4412 Spicewood Springs Rd., Bldg. 600
Austin, Texas 78759-8500
(F. W. T.)

Puslitbang Geoteknologi
Lembaga Ilmu Pengetahuan Indonesia
Bandung, Indonesia
(W. S. S.)

Coral microatolls from the coast and outer-arc islands of Western Sumatra retain a stratigraphic and morphologic record of relative sea-level change, which is due in large part to vertical tectonic deformation above the Sumatran subduction zone. Low water levels, whose fluctuations produce measurable changes in coral morphology, limit the upward growth of the microatolls. Annual rings, derived from seasonal variations in coral density, serve as an internal chronometer of coral growth. The microatolls act as natural long-term tide gauges, recording sea-level variations on time scales of decades. Field observations and stratigraphic analysis of seven microatolls, five from the outer-arc islands and two from the mainland coast, indicate that the Mentawai Islands have been submerging at rates of 4–10 mm/yr over the last four or five decades, while the mainland has remained relatively stable. The presence of fossil microatolls up to several thousand years old in the intertidal zone indicates that little permanent vertical deformation has occurred over that time. Thus, most of the strain accumulated in the past few decades represents interseismic deformation that is recovered during earthquakes. Elastic dislocation models using these submergence data suggest that elastic strain is being accumulated in the interseismic period and that the subduction zone in this region is fully coupled.

This article has been cited by other articles:

				C. P. Rajendran, K. Rajendran, R. Anu, A. Earnest, T. Machado, P. M. Mohan, and J. Freymueller 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, January 1, 2007; 97(1A): S174 - S191. [Abstract] [Full Text] [PDF]

				A. O. Konca, V. Hjorleifsdottir, T.-R. A. Song, J.-P. Avouac, D. V. Helmberger, C. Ji, K. Sieh, R. Briggs, and A. Meltzner Rupture Kinematics of the 2005 Mw 8.6 Nias-Simeulue Earthquake from the Joint Inversion of Seismic and Geodetic Data Bulletin of the Seismological Society of America, January 1, 2007; 97(1A): S307 - S322. [Abstract] [Full Text] [PDF]

				R. W. Briggs, K. Sieh, A. J. Meltzner, D. Natawidjaja, J. Galetzka, B. Suwargadi, Y.-j. Hsu, M. Simons, N. Hananto, I. Suprihanto, et al. Deformation and slip along the Sunda megathrust in the great 2005 Nias-Simeulue earthquake. Science, March 31, 2006; 311(5769): 1897 - 1901. [Abstract] [Full Text] [PDF]

				A Comparative Study of the Sumatran Subduction-Zone Earthquakes of 1935 and 1984 Bulletin of the Seismological Society of America, June 1, 2002; 92(5): 1721 - 1736.