Assessment of Geohazards and Geodynamics by Integrated Gravimetric and Geodetic Methods

通过综合重力和大地测量方法评估地质灾害和地球动力学

• 批准号: RGPIN-2019-07190
• 负责人: Kim, JeongWoo
• 金额: $ 2.26万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=739349
• 关键词: Assessment; Geohazards; Geodynamics; Integrated; Gravimetric

Micro gravimetric monitoring with superconducting gravity meter is effective for estimating small subsurface mass change and redistribution caused by geohazards such as earthquakes, volcanism, and migration and leakage of injected CO2 into geological reservoirs. The gravity signals acquired at the Earth's surface, however, include the effects of surface displacement related to subsurface deformation, and hence, the gravity effect from surface deformation must be accurately estimated and separated from the measured gravity at the surface. This became possible by integrated geodetic techniques such as Interferometric Synthetic Aperture Radar (InSAR) and Global Navigation Satellite System (GNSS) network. In order to monitor, model, and assess geohazards and geodynamics by integrated gravimetric and geodetic methods (Fig. 1), I propose to deploy iGrav superconducting (SG), A-10 absolute (AG), and CG-5 spring gravimeters (RG) to three sites in western and northwestern Canada: 1) the Cascadia subduction zone (CSZ) in BC for earthquake monitoring, 2) the Kluane Lake Research Station (KLRS) in Yukon for induced seismicity and volcanic activity, and 3) the Field Research Station (FRS) geological CO2 storage in Brooks, AB for injected plume monitoring. iGrav SG is the key instrument which will be supported by A-10 and FG-5 AGs and CG-5 RG. Time-varying 2D and 3D gravity monitoring and subsurface modelling will be conducted by integrated SG-AG-RG. Surface displacement will be estimated and modelled by InSAR measurements and GNSS network data. A joint inversion modelling of gravity and ground deformation will be also conducted to derive a subsurface mass redistribution model. These novel methodologies have been developed by the applicant and proven effective in journal publications and patents. Gravity meters will be calibrated at the university Lab and deployed at three sites in turn for data acquisition, depending on the site's data quality and hazard events recorded in the gravity signals. This is a comprehensive gravimetric and geodetic research for a better understanding of the seismic geohazards and securing carbon storage. It also integrates the most advanced satellite radar remote sensing and geodetic technologies that can be readily applied elsewhere in Canada and around the world. This research will provide novel insight into the near-true behavior of tectonic activity through a more realistic geodynamic model. Future geohazards will cost human lives and cause property damage. If the detection of precursors of an earthquake is possible, it can be used for public safety and policy making. It is anticipated that the results from this study will provide new information about the density and mass balance variations, fluid flow and permeability measures, and pressure changes in the CO2 reservoirs, which will subsequently be integrated with the findings of other techniques, such as seismic monitoring, for better interpretation of CO2 storage changes.

利用超导重力仪进行微重力监测，可以有效地估算地震、火山活动、CO2向地质储层的运移和渗漏等地质灾害引起的地下物质的微小变化和再分布。然而，在地球表面获取的重力信号包括与地下变形相关的表面位移的影响，因此，必须准确地估计来自表面变形的重力影响，并将其与在表面测量的重力分离。这是通过综合大地测量技术，如干涉合成孔径雷达（干涉合成孔径雷达）和全球导航卫星系统（GNSS）网络实现的。为了通过综合重力和大地测量方法监测、建模和评估地质灾害和地球动力学，（图1），我建议在加拿大西部和西北部的三个地点部署iGrav超导（SG）、A-10绝对（AG）和CG-5弹簧重力仪（RG）：1）不列颠哥伦比亚省的卡斯卡迪亚俯冲带（CSZ）用于地震监测，2）育空地区的克卢恩湖研究站（KLRS）用于诱发地震和火山活动，和3）位于AB的布鲁克斯的现场研究站（FRS）地质CO2储存，用于注入羽流监测。 iGrav SG是A-10和FG-5 AG以及CG-5 RG支持的关键仪器。时变2D和3D重力监测和地下建模将通过集成SG-AG-RG进行。将通过干涉合成孔径雷达测量和全球导航卫星系统网络数据对地表位移进行估计和建模。还将进行重力和地面变形的联合反演建模，以得出地下质量再分布模型。这些新颖的方法已经由申请人开发，并且在期刊出版物和专利中被证明是有效的。重力仪将在大学实验室进行校准，并依次部署在三个地点进行数据采集，这取决于该地点的数据质量和重力信号中记录的灾害事件。这是一项全面的重力和大地测量研究，旨在更好地了解地震地质灾害和确保碳储存。它还集成了最先进的卫星雷达遥感和大地测量技术，可随时应用于加拿大其他地方和世界各地。这项研究将通过一个更真实的地球动力学模型提供新的见解，接近真实的行为的构造活动。未来的地质灾害将造成人员伤亡和财产损失。如果地震前兆的检测是可能的，它可以用于公共安全和政策制定。预计这项研究的结果将提供有关密度和质量平衡变化、流体流动和渗透率测量以及CO2储层压力变化的新信息，这些信息随后将与地震监测等其他技术的结果相结合，以便更好地解释CO2储存变化。