SGER: The February 28, 2001 Nisqually Earthquake: Juan de Fuca Slab Break-up, Viscoelastic Response, and Interplay with Crustal Faulting

摘要Meghan Millerfield-0119491 PANGA联合体将在普吉湾安装8个连续运行的GPS站，以快速响应尼斯夸利地震。PANGA的这一增强旨在收集基本数据，以回答适当的科学问题。它也展示了板块边界观测站的能力，以协作的方式掌握震后响应的技术挑战。持续的GPS观测将进一步加深我们对这些科学问题的理解：1. 1939年、1946年和1949年记录的一系列板块变形事件是否是一个典型的序列，我们是否会在1999年的格雷港、2001年的尼斯夸利和一些近期的未来事件中观察到类似的序列？2.变形是如何从一个下行板块通过粘弹性岩石圈下部传播到地表变形的？控制这种复杂情况的流变学是什么？变形是如何传播或消散的？3.这些过程如何揭示地震滑动与地震滑动的平衡？4.板内地震与脆性上地壳变形之间是否存在因果关系？5.在普吉特低地，弧前迁移终止于应变集中区，变形集中与下行板块的断裂及其随之而来的变形有何关系？6.在更深的板块事件及其广泛的变形场与构造岩浆变形之间是否存在可观察到的作用？第A011 9491页

AbstractMeghan MillerEAR-0119491The PANGA consortium will install 8 continuously operating GPS stations in Puget Sound in a rapid response deployment to the Nisqually earthquake. This enhancement of PANGA is aimed at gathering basic data to answer opportune scientific questions. It also provides a demonstration of the ability of the Plate Boundary Observatory community to master the technical challenges of a post-earthquake response in a collaborative manner.The continuous GPS observations will further our understanding of these scientific issues:1. Is the series of slab deformation events recorded in 1939,1946 and 1949 a typical sequence, and will we observe a similar sequence in the 1999 Grays Harbor, 2001 Nisqually, and some near term future event(s)?2. How is deformation propagated from a down going slab through a viscoelastic lower lithosphere, to surface deformation? What are the rheologies that govern this complex scenario and how is deformation propagated or dissipated? 3. How do these processes reveal the budget of seismic vs. aseismic slip? 4. Is there a causal relationship between intra-slab earthquakes and deformation in the brittle upper crust?5. How does the concentration of deformation across the Puget Lowlands, where fore-arc migration ends in a zone of concentrated strain, relate to arching of the down-going slab and its consequent deformation?6. Is there an observable role between deeper, slab events with their broad deformation field, and teconomagmatic deformation?Page A011 9491