2005年尼亚斯-西默卢大地震中巽他逆冲断层的变形与滑动。

Deformation and slip along the Sunda megathrust in the great 2005 Nias-Simeulue earthquake.

作者信息

Briggs Richard W, Sieh Kerry, Meltzner Aron J, Natawidjaja Danny, Galetzka John, Suwargadi Bambang, Hsu Ya-Ju, Simons Mark, Hananto Nugroho, Suprihanto Imam, Prayudi Dudi, Avouac Jean-Philippe, Prawirodirdjo Linette, Bock Yehuda

机构信息

Tectonics Observatory, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.

出版信息

Science. 2006 Mar 31;311(5769):1897-901. doi: 10.1126/science.1122602.

DOI:10.1126/science.1122602

PMID:16574861

Abstract

Seismic rupture produced spectacular tectonic deformation above a 400-kilometer strip of the Sunda megathrust, offshore northern Sumatra, in March 2005. Measurements from coral microatolls and Global Positioning System stations reveal trench-parallel belts of uplift up to 3 meters high on the outer-arc islands above the rupture and a 1-meter-deep subsidence trough farther from the trench. Surface deformation reflects more than 11 meters of fault slip under the islands and a pronounced lessening of slip trenchward. A saddle in megathrust slip separates the northwestern edge of the 2005 rupture from the great 2004 Sumatra-Andaman rupture. The southeastern edge abuts a predominantly aseismic section of the megathrust near the equator.

摘要

2005年3月，地震破裂在苏门答腊岛北部近海的巽他逆冲断层带上产生了壮观的构造变形，该断层带长400公里。对珊瑚微环礁和全球定位系统站点的测量显示，在破裂上方的外弧岛屿上，出现了高达3米的与海沟平行的隆升带，以及离海沟更远的一个深度为1米的沉降槽。地表变形反映出岛屿下方断层滑动超过11米，且向海沟方向的滑动明显减少。逆冲断层滑动的一个鞍部将2005年破裂的西北边缘与2004年苏门答腊 - 安达曼大地震破裂分开。其东南边缘紧邻赤道附近逆冲断层的一个主要无震段。