SGER: Coseismic/Postseismic GPS Field Surveys in Response to the 26 December 2004 Mw 9.0 Sumatra Earthquake

我们建议重新测量北苏门答腊、明打威群岛和班达亚齐（Banda Aceh）的约50个大地古迹网，以确定2004年12月26日Mw=9.0苏门答腊地震造成的同震和震后变形。这些新数据将为震源的地震反演提供关键的大地测量约束，约束随后毁灭性海啸的模型，并有助于研究该地区的大地震周期。重新调查这些纪念碑是非常重要的，因为这些是离震中最近的地方（最近的震中在150公里以南）。在这个地区发生的最后一次大地震（8级）是在1833年和1861年。1989-2001年期间，斯克里普斯海洋学研究所（Y. Bock， PI）、伦斯勒理工学院（R. McCaffrey PI）和印度尼西亚国家测绘协调机构（BAKOSURTANAL）在美国国家科学基金会和美国国家航空航天局的资助下对这些大地测量纪念碑进行了调查。在苏门答腊岛和明打威岛上调查了70多个监测站，提供了苏门答腊岛（斜）俯冲带和苏门答腊岛断层的密集覆盖，并对苏门答腊岛断层的几个断面进行了调查，包括受最近灾难影响最严重的班达亚齐地区的一个断面。我们将重点关注2001年在明打威群岛和苏门答腊海岸观测到的26个监测站，以及震中以南明打威群岛的几个监测站，以及班达亚齐的断层带。这项工作将于2005年1月7日开始，由BAKOSURTANAL调查人员进行，他们将评估大地测量纪念碑的状况，执行和分析第一次调查，并为进一步的震后测量奠定基础。与以前nsf资助的苏门答腊研究相关的参考文献：Prawirodirdjo， L.， Y. Bock， R. McCaffrey， J. Genrich， E. Calais， C. Stevens, s.s.o. Puntodewo， C. Subarya， J. Rais， P. Zwick, Fauzi，“苏门答腊俯冲带地震间应变分割的大地测量观测”，地球物理研究通讯，1997,24 （pp. 2601-2604）。mcaffrey， R.， P. Zwick， Y. Bock， L. Prawirodirdjo， J. Genrich， C. W. Stevens， S. S. O. Puntodewo， C. Subarya，“苏门答苏门答岛北部斜板块辐合过程中的应变划分：大地测量学、地震学约束和数值模拟”，地球物理研究，2005,10 （pp. 28,363-28,376）。Prawirodirdjo， L., Y ., Bock, j.f. Genrich, s.s.o. Puntodewo, j.r aiis， C. Subarya, s.s utisna，“基于三角测量和全球定位系统的苏门答腊断层一个世纪的构造变形”，地球物理研究，2005,10 （pp. 28,343-28,361）。Genrich， J.F， Y. Bock， R. McCaffrey， L. Prawirodirdjo， C. W. Stevens， S. S. O. Puntodewo， C. Subarya，“北苏门答腊岛断层系统的滑动分布”，地球物理研究，105,2000（页28,327-28,341）。Bock， Y. L. Prawirodirdjo， J. F. Genrich， C. W. Stevens， R. McCaffrey， C. Subarya, s.s.o. Puntodewo， E. Calais，基于全球定位系统测量的印度尼西亚地壳运动，地球物理学报。学报，108(B8), 2367, doi:10.129/ 2001jb000324,2003。

We propose to resurvey a network of (~50) geodetic monuments in North Sumatra, the Mentawai Islands, and Banda Aceh to determine coseismic and postseismic deformation caused by the 26 December 2004 Mw=9.0 Sumatra earthquake. These new data would provide critical geodetic constraints for the seismographic inversion of the earthquake source, to constrain models of the subsequent devastating tsunamis, and to contribute to the study of the great earthquake cycle in that region. It is very important to resurvey these monuments, since these are the closest available to the earthquake's epicenter (the closest one is 150 km to the south). The last great earthquakes (Mw 8) to occur in this region were in 1833 and 1861. The geodetic monuments have been surveyed in the period 1989-2001 by Scripps Institution of Oceanography (Y. Bock, PI), Rensselaer Polytechnic Institute (R. McCaffrey PI), and the Indonesian National Coordination Agency for Surveying and Mapping (BAKOSURTANAL) with NSF and NASA funding. Over 70 stations were surveyed on Sumatra and the Mentawai islands and provide dense coverage of the Sumatra (oblique) subduction zone and the Sumatra fault, and several transects were surveyed across the Sumatra fault, including one in Banda Aceh, the region most affected by the recent disaster. We will focus on 26 stations observed on the Mentawai Islands and the Sumatran coast in 2001, and several stations just south of the epicenter on the Mentawai islands, as well as the fault transect in Banda Aceh. This effort, to commence on 7 January, 2005 by BAKOSURTANAL survey crews, will assess the condition of the geodetic monuments, perform and analyze the first survey, and set the stage for further postseismic measurements.Relevant references for previous NSF-funded research in Sumatra:Prawirodirdjo, L., Y. Bock, R. McCaffrey, J. Genrich, E. Calais, C. Stevens, S. S. O. Puntodewo, C. Subarya, J. Rais, P. Zwick, and Fauzi, "Geodetic observations of interseismic strain segmentation at the Sumatra subduction zone," Geophysical Research Letters, 24, 1997 (pp. 2601-2604).McCaffrey, R., P. Zwick, Y. Bock, L. Prawirodirdjo, J. Genrich, C. W. Stevens, S. S. O. Puntodewo, and C. Subarya, "Strain partitioning during oblique plate convergence in northern Sumatra: Geodetic and seismologic constraints and numerical modeling," Journal of Geophysical Research, 105, 2000 (pp. 28,363-28,376).Prawirodirdjo, L., Y, Bock, J. F. Genrich, S. S. O. Puntodewo, J. Rais, C. Subarya, and S. Sutisna, "One century of tectonic deformation along the Sumatran fault from triangulation and Global Positioning System surveys, " Journal of Geophysical Research, 105, 2000 (pp. 28,343-28,361).Genrich, J.F., Y. Bock, R. McCaffrey, L. Prawirodirdjo, C. W. Stevens, S. S. O. Puntodewo, and C. Subarya, "Distribution of slip at the northern Sumatran fault system," Journal of Geophysical Research, 105, 2000 (pp. 28,327-28,341).Bock, Y., L. Prawirodirdjo, J. F. Genrich, C. W. Stevens, R. McCaffrey, C. Subarya, S. S. O. Puntodewo, and E. Calais, Crustal Motion in Indonesia from Global Positioning System Measurements, J. Geophys. Res., 108(B8), 2367, doi:10.129/2001JB000324, 2003.