An integrated study of induced earthquakes and crust-mantle seismic structure

诱发地震与壳幔地震结构综合研究

• 批准号: RGPIN-2016-06713
• 负责人: Gu, Yu
• 金额: $ 1.75万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=616474
• 关键词: integrated; study; induced; earthquakes; crust

Earthquakes can be categorized into two main groups: ones that occur as a result of tectonic forces, often referred to as natural earthquakes, and ones that are triggered by human activities such as mining, hydrocarbon production or fluid injection/withdrawal. Natural earthquakes come in all sizes, depths and magnitudes, and the seismic waves associated with them have been widely utilized to infer the structure of the Earth’s interior. On the other hand, anthropogenic sources, also known as induced earthquakes, are less well understood but are being reported at increasing frequencies and sizes. Recent earthquakes in central and western Alberta are compelling case studies in connection with wastewater disposal and hydraulic fracturing (for short, ‘fracking’) operations. The proposed research program in the upcoming years will target both seismic risks in the Western Canada Sedimentary Basin (WCSB) and structures at different spatial scales. The regional component of the proposed program will combine passive-source deployments with laboratory-based analyses of seismic risk and structure. It will take advantage of increased station density and coverage by analyzing the source characteristics and origins of induced earthquakes. It also aims to provide an updated, more accurate map of three-dimensional seismic velocity beneath western Canada. Expected research outcomes pertaining to induced earthquakes may directly impact the environmental policies and decisions vital for the sustained economic growth in the province of Alberta. The extensive database from this regional seismic array also presents a rare opportunity to address scientific issues regarding the crust and mantle seismic structure and the tectonic history of the North American continent. This regional research component will be complemented by a laboratory-based, global analysis of earthquake data. Seismological observations pertaining to the depths and strengths of crust/mantle interfaces provide a crucial link between mineral physics, seismology and thermal/compositional conditions. The availability of broadband data and array-based imaging methods will enable high-resolution snapshots of the crust and mantle beneath various tectonic regimes. The proposed research will utilize high frequency methods (e.g., P'P' precursors), in combination with full waveform inversion and spectral decompositional approaches, to achieve the type of resolution typical of active-source experiments. The two components of the proposed research program are complementary in scale and scope. Together, they form a solid foundation for long-term studies of seismic risks in western Canada and the history/dynamics of both ancient landmasses and more recently formed plate boundary zones. The proposed program will be an integral part of the training of existing graduate students and other highly qualified personnel.

地震可分为两大类：一种是由于构造力而发生的地震，通常称为自然地震，另一种是由人类活动引发的地震，如采矿、碳氢化合物生产或流体注入/抽取。天然地震有各种大小、深度和震级，与之相关的地震波已被广泛用于推断地球内部的结构。另一方面，人为来源，也被称为诱发地震，不太清楚，但报告的频率和规模越来越大。最近在阿尔伯塔中部和西部发生的地震是与废水处理和水力压裂（简称“压裂”）作业有关的引人注目的案例研究。 未来几年的拟议研究计划将针对加拿大西部沉积盆地（WCSB）的地震风险和不同空间尺度的结构。拟议计划的区域部分将联合收割机被动源部署与基于实验室的地震风险和结构分析相结合。它将通过分析诱发地震的震源特征和起源，利用增加的台站密度和覆盖范围。它还旨在提供一个更新的，更准确的三维地震速度在加拿大西部的地图。与诱发地震有关的预期研究成果可能直接影响环境政策和决策，这些政策和决策对阿尔伯塔省的持续经济增长至关重要。这一区域地震阵列的广泛数据库也为解决有关地壳和地幔地震结构以及北美大陆构造史的科学问题提供了难得的机会。 这一区域研究组成部分将得到以实验室为基础的全球地震数据分析的补充。有关地壳/地幔界面深度和强度的地震观测提供了矿物物理学、地震学和热/成分条件之间的重要联系。宽带数据和基于阵列的成像方法的可用性将使各种构造体制下的地壳和地幔的高分辨率快照成为可能。拟议的研究将利用高频方法（例如，P 'P'前兆），结合全波形反演和频谱分解方法，以实现典型的主动源实验的分辨率类型。 拟议研究计划的两个组成部分在规模和范围上是互补的。它们共同构成了加拿大西部地震风险长期研究的坚实基础，以及古代陆块和最近形成的板块边界区的历史/动力学。拟议的计划将成为现有研究生和其他高素质人才培训的一个组成部分。