Collaborative Research: RAPID: Using the M6.4-7.1 Ridgecrest, CA Earthquake sequence to test a postseismic stress evolution monitoring system

合作研究：RAPID：使用加利福尼亚州里奇克莱斯特 M6.4-7.1 地震序列测试震后应力演化监测系统

• 批准号: 1944292
• 负责人: Kaj Johnson
• 金额: $ 2.38万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-15 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1944292&HistoricalAwards=false
• 关键词: Collaborative; Research; RAPID; Using; M6.4

The RAPID project responds to the July Ridgecrest earthquakes in Southern California and develops and tests a tool to monitor stress in the Earth and how it changes after large earthquakes. The project takes GPS and satellite radar data and in near real time computes how the Earth's crust and upper mantle are deforming from the mainshocks and aftershock sequences. This project supports two graduate students to work on developing these new tools and testing them in the immediate aftermath of an earthquake. This project could lead to a future real-time aftershock forecasting method.The first major earthquake in southern California in the last 20 years provides an opportunity to test a postseismic stress evolution monitoring system that would operate in near-real time. Coulomb stress changes from the mainshock of an earthquake are routinely computed to examine the potential for triggering earthquakes on nearby faults. It is known that aftershocks within about one fault-length of the rupture can largely be attributed to coseismic stress changes, but at larger distances, stress changes due to deeper postseismic deformation process such as mantle flow are larger than the coseismic stress change. The Ridgecrest earthquake triggered aftershocks greater than 100 km from the mainshock that are not consistent with Coulomb stress changes from the mainshock.The near real time technique developed through this research has potential to be implemented in future real-time aftershock forecasting. An advantage of this approach is that much of the heavy computation required to compute postseismic deformation is pre-computed and stored. The postseismic deformation calculations are relatively inexpensive and suites of models can be easily computed near real time. The Ridgecrest earthquake sequence provides the first opportunity with modern geodetic data to test a stress evolution monitoring system.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

快速项目对南加州的7月Ridgecrest地震做出了反应，并开发并测试了一种监测地球压力以及大地震后其变化的工具。该项目获取GPS和卫星雷达数据，并在几乎实时计算地球的地壳和上地幔如何从主震和余震序列变形。该项目支持两名研究生致力于开发这些新工具，并在地震发生后立即对其进行测试。该项目可能会导致未来的实时余震预测方法。在过去的20年中，南加州的第一次主要地震提供了测试可在近乎现实时期运行的地震后压力演化监测系统的机会。常规计算从地震的主震中发生的库仑应力变化，以检查触发附近断层地震的潜力。众所周知，在破裂的大约一个断层长度内的余震可能在很大程度上归因于coseis震动应力的变化，但是在较大的距离上，由于更深的后震后变形过程（例如地幔流量）所引起的应力变化（例如地幔流量）大于coseismic震动应激的变化。 Ridgecrest地震引发了距离主震动超过100公里的余震，这些余震与库仑应力的变化不一致。通过这项研究开发的近实时技术技术有可能在未来的实时实时余震预测中实施。这种方法的一个优点是，预先计算和存储了计算后震动变形所需的许多重量计算。后视后变形计算相对便宜，模型的套件可以很容易地实时计算。 Ridgecrest地震序列为测试应力演化监测系统提供了第一个机会。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响审查标准，被认为值得通过评估来获得支持。