Collaborative Research: Continuation Of A GPS and Seismic Study of the Subduction Earthquake Cycle: Jalisco, Mexico

合作研究：继续进行俯冲地震周期的 GPS 和地震研究：墨西哥哈利斯科州

• 批准号: 0510395
• 负责人: Joann Stock
• 金额: $ 19.74万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0510395&HistoricalAwards=false
• 关键词: Collaborative; Research; Continuation; GPS; Seismic

Funds for a four-year, third and final phase of a GPS-based study of theColima-Jalisco region of western Mexico are requested. Since early 1995,two large magnitude earthquakes (M=8.0 and M=7.6) have ruptured the MiddleAmerica subduction interface directly offshore from a 30-station GPS network,most recently in January of 2003. These earthquakes have afforded an exceptionalopportunity to study the coseismic and postseismic effects of largesubduction earthquakes, including the gradual decay of postseismic faultafterslip and viscoelastic flow and re-emergence of interseismic elasticstrain accumulation. Studying these earthquakes and their after effectshave numerous intellectual merits, outlined below. Specific goals forthe proposed project are as follows: (1) Continue annual measurements of theregional velocity field to characterize spatial variations in viscoelasticflow and afterslip triggered by the Mw=8.0 Oct. 9, 1995 Colima-Jalisco andM_w=7.6, 1.22.2003 Tecoman earthquakes, (2) Construct a six-station continuousGPS network to better characterize the temporal evolution of these viscoelasticand afterslip responses and better separate them from the underlying linearelastic strain accumulation. Continuous measurements will enable determine ofwhether the Cocos/Rivera subduction interfaces accommodate downdip transientaseismic slip events similar to those recently described for Cascadia, Japan,and southern Mexico. (3) Complete modeling of the coseismic and post-seismiceffects of the 2003 Tecoman earthquake using existing and new observations,including a joint inversion of the geodetic and seismic constraints,collaborative analysis of local seismic data for aftershock relocations, andsensitivity analysis for our assumed elastic constants, layer thickness,and subduction interface geometry. (4) Employ measured variations inthe direction and magnitude of interseismic strain accumulation toboth estimate the degree of locking along the Rivera and Cocos platesubduction interfaces and relate onshore strain accumulation tothe oceanic plate motion. (5) Determine how the 1995 Colima-Jalisco earthquakeand subsequent processes altered stress levels in the adjacent Tecoman earthquakerupture zone. (6) Extract information about upper plate deformation associatedwith the continental rifts in our field area from GPS, seismic, and ShuttleRadar Topographic Mission data. As has been the case in previous stages ofthis project, the present phase of the project will have numerous broader impacts.Three Mexican scientists will participate as official collaborators: Osvaldo Sanchezof UNAM, Bertha Marquez of the Universidad de Guadalajara, and Gabriel Reyes ofthe University of Colima, as well as Mexican undergraduate and graduate studentsfrom three universities. In addition, support is requested for a UW graduate studentto continue his finite element modeling of the geodetic data for his dissertation,a Caltech graduate student who will work with Gabriel Reyes on local seismic data,and two REU undergraduates who will work under Stock's guidance. Data from the newcontinuous sites will constitute a useful legacy for other investigators, particularlyfor detecting and characterizing transient signals related to aseismic slip alongthe subduction interface.

要求对西墨西哥州西部 - 贾利斯科地区的基于GPS的研究的四年，第三阶段也是最后一个阶段的资金。 Since early 1995,two large magnitude earthquakes (M=8.0 and M=7.6) have ruptured the MiddleAmerica subduction interface directly offshore from a 30-station GPS network,most recently in January of 2003. These earthquakes have afforded an exceptionalopportunity to study the coseismic and postseismic effects of largesubduction earthquakes, including the gradual decay of postseismic faultafterslip and viscoelastic flow并重新出现了经济势弹性弹性的积累。研究这些地震及其后效应阳性的众多智力优点，以下概述。 Specific goals forthe proposed project are as follows: (1) Continue annual measurements of theregional velocity field to characterize spatial variations in viscoelasticflow and afterslip triggered by the Mw=8.0 Oct. 9, 1995 Colima-Jalisco andM_w=7.6, 1.22.2003 Tecoman earthquakes, (2) Construct a six-station continuousGPS network to better characterize the temporal evolution of these粘弹性和后层后反应，并更好地将它们与潜在线性弹性应变的积累分开。连续测量将确定可可/里维拉俯冲界面是否可容纳与最近描述的卡斯卡迪亚，日本和墨西哥南部所描述的下降瞬态酶震动事件。 （3）使用现有和新的观察结果的2003年Tecoman地震的Coseismisic和seismiceCefects的完整建模，包括对测量和地震约束的联合反转，对余（余（后弹）重新固定的地方地震数据的共同分析，以及我们假定的弹性常量，厚度厚度，厚度，层次和sabdriction和sak decultion和sepry gelilect和sab decultion和secretions，以及对我们的敏感性分析。 （4）采用了经过大小写应变积累的方向和幅度的测量变化，预越估计沿里维拉（Rivera）和可可板板块的锁定程度，并将陆上应变堆积物与海洋板板运动相关联。 （5）确定1995年的Colima-Jalisco地震后续过程如何改变邻近的Tecoman地震爆发区的应力水平。 （6）提取有关上板变形的信息，与GPS，地震和Shuttleradar地形任务数据相关的大陆裂痕与我们的田间区域中的大陆裂谷有关。 As has been the case in previous stages ofthis project, the present phase of the project will have numerous broader impacts.Three Mexican scientists will participate as official collaborators: Osvaldo Sanchezof UNAM, Bertha Marquez of the Universidad de Guadalajara, and Gabriel Reyes ofthe University of Colima, as well as Mexican undergraduate and graduate studentsfrom three universities.此外，向UW研究生提供了支持，以继续他的论文大地测量数据的有限元模型，加州理工学院的研究生将与加布里埃尔·雷耶斯（Gabriel Reyes）一起在当地的地震数据上工作，两名将在库存指导下工作的REU本科生。来自新连续站点的数据将构成其他研究人员的有用遗产，特别是检测和表征与俯冲界面沿俯冲界面相关的瞬态信号。