RAPID: Collaborative Research: GPS observations of post-seismic deformation from the 3 Sep 2016, Mw 5.8, Pawnee, Oklahoma

我们建议在波尼地震地区使用GPS技术来测量地震造成的地面缓慢移动，预计在未来1-2年内将在那里发生。这些所谓的？震后？的原因之一？天然地震后的运动是断层周围的流体对地震产生的新的地壳应力场的重新调整。自2009年以来，俄克拉荷马州石油生产废水的注入从5倍增加到10倍，这种增加的注入速度被认为导致该州地震数量同时增加了450%。波尼地震是俄克拉荷马州最大的历史事件，如果证实是诱发的，也是迄今为止世界上最大的诱发地震之一。这项拟议的工作将首次捕捉到与地震活动板块边界无关的地震的震后形变场，例如加州现有的板块边界，如果证实是诱发的，则是人为诱发的地震。对震后信号的分析将有助于理解流体以及流体的注入在天然地震和可能的诱发地震中的作用，并指导制定减轻流体注入造成的地震破坏的策略。我们建议安装8个具有测地纪念性的连续GPS(CGPS)站，在2016年9月3日俄克拉荷马州波尼市5.8级地震的震中地区进行震后形变测量。除了是板内地震，也是俄克拉荷马州历史上最大的地震，这次地震还发生在自2009年初以来地震活动呈指数级增加的地区，我们认为这与注入石油生产废水的速度显著增加有关。这种规模的地震应该在几年的时间内产生可测量的震后形变信号，可以提供有关该事件以及震中地区地壳和断层的性质和状态的重要信息。CGPS测量将补充这次地震的地震和其他地球物理研究，提供地震后地壳变形的数据，特别是地震造成的流体孔洞弹性分量。这些数据将对模拟地壳和断层属性至关重要，可能有助于提高我们对流体在地震过程中的作用的理解，并减少诱发地震造成的地震风险。

We propose to use GPS technology in the area of the Pawnee earthquake to measure slow movements of the ground caused by the earthquake that are expected to occur there during the next 1-2 years. One of the causes of these so-called ?post-seismic? movements after natural earthquakes is the readjustment of fluids around the fault to the new crustal stress field generated by the earthquake. The injection of wastewater in Oklahoma from oil production has increased from 5 to 10 times since 2009, and this increased injection rate is thought to have induced a concurrent 450% increase in the number of earthquakes in this state. The Pawnee earthquake is the largest historical event in Oklahoma and, if confirmed that it is induced, among the largest induced earthquakes to date worldwide. The proposed work will provide the first capture of the postseismic deformation field of an earthquake not associated with a seismically active plate boundary such as the existing in California, and if confirmed that it is induced, a human induced earthquake. Analysis of the post-seismic signal will contribute to understanding the role of fluid, and the injection of fluid, in both natural and possibly induced earthquakes, and guide development of strategies to mitigate damage from earthquakes induced by fluid injection.We propose installing 8 geodetically monumented, Continuous GPS (CGPS) stations to perform post-seismic deformation measurements in the epicentral region of the 3 September 2016, M 5.8, Pawnee, Oklahoma earthquake. In addition to being intraplate, and the largest historical earthquake in Oklahoma, this event also occurred within a region experiencing an exponential increase in seismic activity since the start of 2009 that we think is related to a significant coincident increase in the rate of disposal by injection of wastewater from petroleum production. An earthquake this size should produce a measurable postseismic deformation signal over a period of a few years that can provide important information about the event and the properties and state of the crust and faults in the epicentral region. The CGPS measurements will complement seismic and other geophysical studies of this earthquake by providing data on post-seismic crustal deformation, especially the fluid poroelastic component, caused by the earthquake. Such data will be essential for modeling crustal and fault properties, potentially contribute to improving our understanding the role of fluids in the earthquake process, and reducing seismic hazard from induced earthquakes.