印度尼西亚马达大学Cecep Pratama小组取得一项新突破。他们报道了根据GNSS导出的连续应变率推断的印度尼西亚明打威弧前带的应变积累。该项研究成果发表在2024年5月7日出版的《大地测量与地球动力学》上。

研究小组利用连续的全球导航卫星系统(GNSS)观测数据，以大地应变率为主题，识别当前区域地壳形变。主应变率、膨胀率和最大剪切应变率分别约为每年微应变0.13、每年微应变0.2和每年微应变0.1，其不确定度范围为每年微应变0.01-0.04。研究发现，扩张和最大剪切应变率揭示了明打威前弧带走滑复式和逆冲构造的空间覆盖范围。

据介绍，明打威弧前带(MFS)以斜向变形为特征，在正、平行海沟板块辐合带之间形成滑动分割。从2004年到2012年，沿着邻近的巽他海沟发生的大地震留下了一个被称为明打威地震断裂带的大片完整区域。

附：英文原文

Title: Strain accumulation in the Mentawai Forearc Sliver, Indonesia, inferred from continuous GNSS-derived strain rate

Author: Cecep Pratama a

Issue&Volume: 2024/05/07

Abstract: The Mentawai Forearc Sliver (MFS) is characterized by oblique deformation formed as slip partitioned between normal and parallel trench plate convergence. The surge of great earthquakes from 2004 to 2012 along the adjacent Sunda trench left a large unbroken segment known as the Mentawai Seismic Gap. Here, we adopted continuous Global Navigation Satellite System (GNSS) observation data to identify the present regional crustal deformation using geodetic strain rates. The principal strain rate, dilatation rate, and maximum shear strain rate are about 0.13 microstrain/yr, 0.2 microstrain/yr, and 0.1 microstrain/yr, respectively, with the range of its uncertainties between 0.01 and 0.04 microstrain/yr. It is found that dilatation and maximum shear strain rates reveal the spatial coverage of strike-slip duplex and backthrust tectonics along the Mentawai Forearc Sliver.

DOI: 10.1016/j.geog.2024.04.003

Source: https://www.sciencedirect.com/science/article/pii/S1674984724000363