Collaborative research: Investigating effects of geologic complexity on induced seismicity, using M0-M5.7 seismicity from Prague, Oklahoma

合作研究：利用俄克拉荷马州布拉格的 M0-M5.7 地震活动研究地质复杂性对诱发地震活动的影响

• 批准号: 1649771
• 负责人: Heather Savage
• 金额: $ 20.18万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-01 至 2020-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1649771&HistoricalAwards=false
• 关键词: Collaborative; research; Investigating; effects; geologic

The recent surge in induced seismicity in the Midwestern United States, during which Oklahoma has catapulted past California in seismicity rate, has created controversy, captured the attention of the general public, and influenced policy. As a result, induced seismicity has become a focal point of earthquake science in the United States over the last few years; however, much remains to be learned about the mechanisms of induced seismicity. In this research the well-recorded 2011 Prague, OK earthquake sequence will be used to investigate deformation on a scale not commonly obtainable in seismicity studies (earthquake location with precision ~10 meters). Such well-located earthquakes allow for better understanding of how complex faults fail. Furthermore, laboratory experiments on the rocks from the Prague area will provide information on how strong and stable the faults are, and how pumping fluids into the faults might promote earthquakes.The Prague sequence contains three earthquakes greater than Mw5 and their robust aftershock sequences, as well as the foreshock sequences for two large events. The precision with which the Prague earthquakes can be located allows the failure processes to be considered on a scale comparable to fault structures measured in studies of exhumed faults. In addition, complementary laboratory experiments on lithologies from the Prague area will allow study of the effects of fluid pressure on fault strength and stability. The ultimate goal is to use the Prague dataset to probe the influence of fluid pressure and fault zone complexity on earthquake nucleation, propagation, and arrest. Specifically this work will address the following questions: 1) Do the faults near Prague show precursory activity that could be used to forecast rupture? 2) How does complex fault geometry control rupture? and 3) How do fault strength, strength heterogeneity, and fault stability play a role in induced earthquakes?

最近美国中西部诱发地震活动激增，俄克拉荷马州的地震活动率一跃超过加利福尼亚州，引起了争议，吸引了公众的注意力，并影响了政策。因此，诱发地震活动在过去几年中已成为美国地震科学的焦点。然而，关于诱发地震活动的机制还有很多东西有待了解。 在这项研究中，记录良好的 2011 年俄克拉何马州布拉格地震序列将用于研究地震活动性研究中通常无法获得的尺度变形（地震定位精度约为 10 米）。这种位置良好的地震可以让我们更好地了解复杂断层是如何失效的。 此外，对布拉格地区岩石进行的实验室实验将提供有关断层强度和稳定性的信息，以及将流体泵入断层如何促进地震。布拉格序列包含三场大于 Mw5 的地震及其强烈的余震序列，如以及两次大型事件的前震序列。布拉格地震的定位精度使得可以在与挖掘断层研究中测量的断层结构相当的规模上考虑破坏过程。此外，对布拉格地区岩性的补充实验室实验将有助于研究流体压力对断层强度和稳定性的影响。最终目标是利用布拉格数据集探讨流体压力和断层带复杂性对地震成核、传播和停止的影响。具体来说，这项工作将解决以下问题：1）布拉格附近的断层是否显示出可用于预测破裂的前兆活动？ 2）复杂的断层几何形状如何控制破裂？ 3）断层强度、强度异质性和断层稳定性如何在诱发地震中发挥作用？