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：由构造力引起的地震，通常称为自然地震，以及由采矿、碳氢化合物生产或流体注入/抽取等人类活动引发的地震。各种大小、深度和震级以及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，人为源（也称为诱发地震）的了解较少，但已得到广泛应用。最近阿尔伯塔省中部和西部发生的地震的频率和规模不断增加，是与废水处理和水力压裂（简称“水力压裂”）作业相关的引人注目的案例研究。 未来几年拟议的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把被动源部署与基于实验室的地震风险分析结合起来。它将通过分析诱发地震的震源特征和起源，利用增加的站密度和覆盖范围，提供与加拿大西部相关的最新、更准确的三维地震速度图。诱导的地震可能会影响对阿尔伯塔省持续经济增长直接至关重要的环境政策和决策，该区域地震阵列的广泛数据库也为解决地壳和地幔地震结构以及构造历史的科学问题提供了难得的机会。北美大陆。 该区域研究部分将得到基于实验室的全球地震数据分析的补充，涉及地壳/地幔界面的深度和强度，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将能够对各种构造状态下的地壳和地幔进行高分辨率快照，拟议的研究将利用高频方法（例如，P'P'前体），并结合全面的技术。波形反演和频谱分解方法，以实现有源源实验典型的分辨率类型。 拟议研究计划的两个组成部分在规模和范围上是互补的，它们共同为加拿大西部地震风险以及古代大陆和最近形成的板块边界区域的历史/动态研究奠定了坚实的基础。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。