Seismotectonics of the Lesser Antilles Arc

小安的列斯群岛弧的地震构造

• 批准号: 2892607
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2892607
• 关键词: Seismotectonics; Lesser; Antilles; Arc

Background: Subduction zones are the sites of the world's largest earthquakes, sometimes generating devastating tsunamis. The earthquake potential of the Lesser Antilles Arc (LAA) is poorly known, largely because of the challenge of obtaining data along this arc of small islands. Two historic earthquakes are thought to have been classical subduction thrust events, possibly with tsunamigenic potential. However, the extent of megathrust seismic coupling remains debated. The potential risk to large, poorly-protected communities in the Caribbean region is large.Rationale: In a recent large consortium grant, VoiLA, we collected new seismic data, including seabed-installed instruments, in and around the LAA. Data from our experiment has been used to image the subduction zone in unprecedented detail. We have compiled a preliminary catalogue of earthquakes detected during our deployment and developed a new moment tensor method to characterise faulting styles. We have been able to track how regions of more extensively hydrated incoming plate correlate with concentrations of small earthquakes and enhanced volcanic productivity along the arc. The next stage is to undertake an in-depth analysis of the VoiLA data to improve understanding of earthquake potential of the LAA.This project: In this PhD project the VoiLA seismic data will be used together with thermal and mechanical odels of the subduction zone to improve the understanding of the seismic potential and tectonics of the LAA. Machine learning techniques will be used to identify and locate as many events as possible, to characterise the spatial distribution, size-frequency characteristics and where possible styles of events. These results will be combined with existing earthquake catalogues, and then compared with predictions of the thermal structure and subducting plate stresses from models that are tailored based on our detailed imaging of the subduction zone. Given the LAA is an important end-member, where slow-convergence of The student would join the Imperial Plates, Mantle and Core group working on shallow and deep geophysical imaging, surface processes and mantle dynamics.

背景：俯冲带是世界上最大地震的发生地，有时会引发毁灭性的海啸。小安的列斯群岛弧 (LAA) 的地震潜力鲜为人知，主要是因为沿这条小岛弧获取数据存在挑战。历史上的两次地震被认为是经典的俯冲逆冲事件，可能具有引发海啸的潜力。然而，巨型逆冲地震耦合的程度仍然存在争议。加勒比地区保护不善的大型社区面临的潜在风险很大。理由：在最近的大型财团资助项目 VoiLA 中，我们收集了 LAA 及其周边地区的新地震数据，包括海底安装的仪器。我们的实验数据已被用来以前所未有的细节对俯冲带进行成像。我们编制了部署期间检测到的地震的初步目录，并开发了一种新的力矩张量方法来表征断层类型。我们已经能够追踪更广泛水合的传入板块区域如何与小地震集中度和沿弧线火山生产力增强的相关性。下一阶段是对 VoiLA 数据进行深入分析，以提高对 LAA 地震潜力的了解。该项目：在这个博士项目中，VoiLA 地震数据将与俯冲带的热模型和力学模型一起使用，以提高对 LAA 地震潜力和构造的了解。机器学习技术将用于识别和定位尽可能多的事件，以表征事件的空间分布、大小频率特征以及事件的可能风格。这些结果将与现有的地震目录相结合，然后与根据我们对俯冲带的详细成像定制的模型对热结构和俯冲板块应力的预测进行比较。鉴于 LAA 是一个重要的终端成员，学生的缓慢收敛将加入帝国板块、地幔和核心小组，致力于浅层和深层地球物理成像、表面过程和地幔动力学。