Collaborative Research: Mapping the Rivera Subduction Zone

合作研究：绘制里维拉俯冲带地图

• 批准号: 0335802
• 负责人: James Ni
• 金额: $ 19.57万
• 依托单位: New Mexico State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-15 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0335802&HistoricalAwards=false
• 关键词: Collaborative; Research; Mapping; Rivera; Subduction

The investigators plan to deploy fifty broadband seismic instruments throughout the Jalisco and Colima provinces in Mexico. This region of Mexico is being underthrust by the Rivera microplate and has witnessed the largest earthquake in Mexican history. The subduction of the Rivera plate has also resulted in the overriding plate, the Jalisco block, separating from the rest of Mexico along two perpendicular grabens. The Jalisco block is also volcanically active with the Colima volcano unusually close to the trench. This region is a type example of the processes that can occur when a ridge meets a subduction zone. The tectonics of the region has been postulated to be due to the interaction of the Rivera plate and the overriding Jalisco block but little geophysical data exist to truly understand the subsurface interactions. In this project researchers will image the geometry of the Rivera plate at depth including a search for tears with the adjacent Cocos plate or evidence of breaking up of the Rivera plate at depth, both of which have been postulated. In this work tomographic imaging tools as well as receiver function analysis will be employed. Careful mapping of the slab surface as well as the locations and mechanisms of earthquakes in the region will provide constraints on the region of coupling between the Jalisco and Rivera plates. This will provide useful information for the ongoing GPS projects funded by NSF in this region that will ultimately help with hazard analysis. The investigators will also attempt to image the mantle wedge to better understand the volcanism in the region. Using shear wave splitting we hope to understand mantle flow beneath the Jalisco block. This study should have broader impact in understanding the evolution of plate boundaries when ridges interact with subduction zones. This has occurred in the geologically recent past off the coast of California and northern Mexico. This research includes a substantial international collaboration with Mexican colleagues from several institutions.This project is co-sponsored by the Americas Program in the Office Of International Science And Engineering.--

调查人员计划在整个哈利斯科州和墨西哥的科利马省部署五十个宽带地震仪器。墨西哥这个地区正在被里维拉（Rivera）微板岩镇定，目睹了墨西哥历史上最大的地震。 Rivera板的俯冲也导致了覆盖板，即哈利斯科街区，沿着两个垂直抓地力与墨西哥其他地区分开。哈利斯科州的街区也具有火山活跃，而科里玛火山异常接近沟渠。该区域是当山脊遇到俯冲带时可能发生的过程的一个示例。该地区的构造学是由于Rivera板块的相互作用和覆盖的Jalisco块造成的，但几乎没有地球物理数据实际上可以理解地下相互作用。在这个项目中，研究人员将在深度上对Rivera板的几何形状进行想象，包括在相邻的可可板中寻找眼泪或在深度分解Rivera板的证据，这两种板都已假设。在此工作中，将采用层析成像成像工具以及接收器功能分析。仔细地映射平板表面以及该地区地震的位置和机制将对哈利斯科州和里维拉板之间的耦合区域提供约束。这将为NSF在该地区资助的正在进行的GPS项目提供有用的信息，最终将有助于进行危害分析。调查人员还将尝试对地幔楔进行成像，以更好地了解该地区的火山。使用剪切波拆分，我们希望了解哈利斯科街区下方的地幔流。当脊与俯冲带相互作用时，这项研究应在理解板边界的演变方面具有更大的影响。这发生在加利福尼亚和北部墨西哥沿海地区的地质近代。这项研究包括与来自多个机构的墨西哥同事进行的实质性国际合作。该项目是由美洲计划在国际科学与工程办公室共同赞助的。