Subduction Zone Coupling and Strain Partitioning in the Philippine Plate Boundary Zone

菲律宾板块边界带的俯冲带耦合与应变划分

• 批准号: 1215658
• 负责人: Michael Hamburger
• 金额: $ 9.99万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1215658&HistoricalAwards=false
• 关键词: Subduction; Zone; Coupling; Strain; Partitioning

This pilot research project seeks to examine active tectonic processes in a complex, subduction-dominated plate boundary zone in the Philippines island arc through analysis of the surface deformation field using high-precision GPS measurements. The project takes advantage of a newly available suite of data from a 240-station network of continuous and campaign GPS sites in the Philippine plate boundary zone, collected by the Philippine Institute of Volcanology and Seismology (PHIVOLCS), together with international collaborators. The project builds on a successful research collaboration between Indiana University, PHIVOLCS, and two research institutes in Taiwan. The work will focus on (1) improvement of regional plate motion and intraplate deformation models for the Philippine island arc; (2) evaluation of strain partitioning between subduction-related compression and intra-arc shear deformation in Luzon, including assessment of post-seismic transient effects associated with the large (Mw 7.7) 1990 Luzon earthquake; and (3) assessment of spatially variable subduction zone coupling along the Manila and Philippine trenches and its impact on earthquake potential. This proposal seeks to extend and expand the ongoing studies in Luzon through analysis of existing crustal deformation data, in collaboration with Philippine and Taiwanese counterparts. Tasks include (1) extending kinematic modeling of elastic block interaction to include the entire Philippine archipelago; (2) developing 3-D deforming block models of fault-related deformation at the Philippine Fault and interaction with subduction boundaries; and (3) examining spatially variable coupling along the Manila and Philippine subduction zones through dynamic modeling of subduction-zone creeping and locked segments. The expected models of plate boundary earthquake potential can be used as input for ground-motion and tsunami-generation models.This project has significant societal impacts in the form of improved methods for detecting fault-related deformation and subduction-zone activity in active plate boundary zones. In particular, these observations will provide critical information for assessment of long-term seismic hazards for the Philippines.PHIVOLCS and other Philippine collaborators provides an avenue for technology transfer to colleagues in the developing world. Because of the large population at risk from future earthquakes and related secondary effects, the research conducted as part of this project could have significant impacts in hazard mitigation for the Philippines. The project would provide support for students at Indiana University and ongoing science outreach activities.

这一试点研究项目力求通过使用高精度全球定位系统测量数据分析地表变形场，研究菲律宾岛弧内一个复杂的、俯冲为主的板块边界区的活跃构造过程。该项目利用了菲律宾火山学和地震学研究所与国际合作者一起从菲律宾板块边界区240个连续和活动全球定位系统站点网络收集的一套新的数据。该项目建立在印第安纳州大学PHIVOLCS和台湾两个研究机构之间成功的研究合作基础上。这项工作的重点是：（1）改进菲律宾岛弧的区域板块运动和板内变形模型;（2）评估吕宋岛与俯冲有关的压缩和弧内剪切变形之间的应变分配，包括评估与大规模地震有关的震后瞬态效应;（3）评估菲律宾岛弧的地壳运动和板块内变形。（3）沿沿着马尼拉和菲律宾海沟的空间可变俯冲带耦合及其对地震潜在性的影响的评估。该建议旨在通过与菲律宾和台湾同行合作，分析现有的地壳变形数据，扩展和扩大吕宋岛正在进行的研究。任务包括：（1）将弹性块体相互作用的运动学建模扩展到包括整个菲律宾群岛;（2）开发菲律宾断层处断层相关变形和与俯冲边界相互作用的三维变形块体模型;（3）通过俯冲带蠕动和锁定段的动力学建模，检查沿马尼拉和菲律宾俯冲带沿着的空间可变耦合。板块边界地震潜力的预期模型可用作地面运动和海啸生成模型的输入。该项目具有重大的社会影响，其形式是改进检测活动板块边界区断层相关变形和俯冲带活动的方法。特别是，这些观测将为评估菲律宾的长期地震危险提供重要信息，菲律宾地震研究所和其他菲律宾合作者为向发展中世界的同事转让技术提供了一个途径。由于大量人口面临未来地震和相关次生影响的风险，作为该项目一部分进行的研究可能对菲律宾减灾产生重大影响。该项目将为印第安纳州大学的学生和正在进行的科学推广活动提供支持。