Seismological studies of plate tectonic boundaries and rifted margins

板块构造边界和裂谷边缘的地震学研究

• 批准号: RGPIN-2020-05562
• 负责人: Nedimovic, Mladen
• 金额: $ 4.44万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=750949
• 关键词: Seismological; studies; plate; tectonic; boundaries

The proposed research program is focused on plate boundaries and major transition zones in the Earth's solid outer layer, the lithosphere. The plate boundaries under investigation, namely subduction zones, mid-ocean ridges and transform faults, as well as the continent-ocean transitions found at rifted margins and internal to the plates, all form as part of the Earth's plate tectonic cycle. Subduction zones are places where oceanic and continental plates converge, where the thinner but denser oceanic plate sinks under the continental plate to eventually recycle into the Earth's mantle, and where the largest earthquakes on Earth occur. At transform margins, plates slide past one another, producing earthquakes with magnitudes second only to those occurring on subduction thrusts. Mid-ocean ridges are divergent plate tectonic boundaries where new oceanic crust is continuously generated. They make up the most extensive mountain system and the longest chain of volcanoes on Earth. Rifted continental margins form by extension and breakup of the continental lithosphere, a process that creates new ocean basins. The proposed research program will apply state-of-the-art data analysis methods to active and passive source seismic data. The goal is to investigate the targeted subsurface structures at unprecedented resolution in order to test leading scientific hypotheses and answer questions that have the potential to transform our understanding of plate boundaries. The selected study areas are: Cascadia Subduction Zone, Queen Charlotte Fault, Southwest Indian Ridge, and Western Baffin Bay. The study areas and problems to be addressed are chosen based on their suitability for achieving my short- and long-term science goals, the potential for high-impact discoveries, their economic and societal impacts, and interest to a broad group of earth scientists and general public. Earthquakes and the associated tsunamis, as well as volcanic eruptions pose significant hazards to Canadians and our infrastructure. Improved constraints on the geometry and character of seismogenic zones and seismicity in general, an anticipated outcome of the planned research, will lead to more accurate probabilistic seismic hazards maps and improved building codes. These are the primary means used to mitigate earthquake damage. New constraints on the deep structures at rifted margins, which host the largest recently drilled hydrocarbon deposits, will help guide future exploration. All of the projects that comprise the proposed research program are high-profile international collaborations because investigations of structures deep below the seabed, which is one of the Earth's last frontiers, require major resources, both human and technological. This cutting-edge collaborative environment presents an excellent opportunity to train HQP that will one day lead the next generation of researchers to new discoveries.

提出的研究计划集中在地球固体外层岩石圈中的板边界和主要过渡区域上。正在研究的板边界，即俯冲带，中山脊和转换断层，以及在裂谷边缘和板内的大陆 - 海洋转变，都是地球板构造循环的一部分。俯冲带是海洋和大陆板融合的地方，在大陆板下面较薄但更密集的海洋板下沉，最终将其回收到地球地幔中，以及地球上最大的地震发生。在变形边缘，板相互滑动，产生大幅度的地震，仅次于俯冲推力上发生的地震。海脊中脊是板块构造边界，不断产生新的海洋壳。它们构成了地球上最广泛的山系统和最长的火山链。大陆岩石圈的扩展和破裂形成了裂痕的大陆边缘，这一过程创造了新的海洋盆地。拟议的研究计划将将最新的数据分析方法应用于主动和被动的源地震数据。目的是以前所未有的分辨率研究目标的地下结构，以检验主要的科学假设并回答有可能改变我们对板界的理解的问题。选定的研究领域是：卡斯卡迪亚俯冲带，夏洛特皇后断层，西南印度山脊和西巴芬湾。研究领域和问题是根据其适合实现我的短期和长期科学目标，高影响力发现的潜力，其经济和社会影响的潜力以及广泛地球科学家和公众的兴趣的选择。地震和相关的海啸以及火山喷发对加拿大人和我们的基础设施造成了重大危害。对计划研究的预期结果，对地震区和地震性的几何形状和特征的限制将导致更准确的概率地震危害图和改进的建筑法规。这些是减轻地震损害的主要手段。对裂谷边缘的深层结构的新约束，该结构是最近钻孔碳氢化合物沉积物的最大构成，将有助于指导未来的探索。构成拟议的研究计划的所有项目都是备受瞩目的国际合作，因为对海床深处的结构的调查（这是地球最后的前沿之一），需要人类和技术的主要资源。这种尖端的协作环境为培训HQP提供了一个绝佳的机会，有一天将带领下一代研究人员获得新发现。