Small Grants for Exploratory Research: Collaborative Project: Rapid Response to the November 14, 2001 Kunlun Fault Earthquake

EAR-0209434/EAR-0209892Shen Cheng-Kang/Freymueller 美国阿拉斯加大学、加州大学洛杉矶分校和中国地震局的科学家正在对2001年11月14日西藏昆仑断层7.9级地震进行快速响应。这次地震提供了一个独特的机会来测量在现有大地测量网络内发生的 M~8 地震的震后变形，该网络的相对速度已知约为 1 毫米/年。中国地震局在地震发生一周后在破裂附近建立了三个连续记录的 GPS 站点，并在距该地震约 150 公里的地方建立了第四个 GPS 站点。此外，2001年12月，对青藏公路沿线的17个现有和新的GPS站点进行了勘察。第二次野外活动是将GPS网络从青藏公路向西延伸，在近场地表破裂两侧的断层上增加新的站点。这项调查正在对 11 月至 12 月调查的所有地点进行重复测量，提供初步的震后结果。这些测量将有助于更好地了解异常厚的藏北地壳的流变结构以及如此大的事件引发的震后过程。

EAR-0209434/EAR-0209892Shen Zheng-Kang/FreymuellerScientist from the University of Alaska, University of California Los Angeles, and the China Seismological Bureau are carrying out a a rapid response to the November 14, 2001 Mw~7.9 Kunlun fault earthquake in Tibet. This earthquake provides a unique opportunity to measure the postseismic deformation of an M~8 earthquake that occurred within a pre-existing geodetic network in which relative site velocities are known to about 1 mm/yr., Three continuously recording GPS sites near the rupture and a fourth about 150 km away were established one week after the event by the China Seismological Bureau. Also, 17 existing and new GPS sites along the Qinghai-Tibet highway were surveyed in December, 2001. A second field campaign is extending GPS network westward from the Qinghai-Tibet highway, adding new sites along the fault on either side of surface rupture in the near field. This survey is repeating measurements at all of the sites surveyed in November-December, providing the initial postseismic results. These measurements will lead to a better understanding of the rheological structure of the exceptionally thick northern Tibetan crust as well as the postseismic processes triggered by such a large event.