Collaborative Research: Great Earthquakes, Megathrust Phenomenology and Continental Dynamics in the Southern Andes

合作研究：安第斯山脉南部的大地震、巨型逆冲现象学和大陆动力学

• 批准号: 1118514
• 负责人: Michael Bevis
• 金额: $ 130万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2018-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1118514&HistoricalAwards=false
• 关键词: Collaborative; Research; Great; Earthquakes; Megathrust

The overall goal of the project is to understand the processes that created and now drive evolution of the modern Andes. In order to do that, we must understand the spatial and temporal variability of stresses generated in the upper plate by coupling at the plate interface and by viscous drag of the asthenosphere. Specifically, the project will focus on the 2010 Mw 8.8 Maule earthquake in Chile, the earthquake cycle along the Nazca-South America plate interface, orogenesis of the Andean system, and its relationship to crustal deformation and mantle flow. The project is structured around two main themes:? How does megathrust phenomenology influence or control the architecture, from forearc to backarc, of the Andean orogeny? ? How do geological materials, shallow structure and slab/mantle dynamics influence or control the behavior and evolution of the megathrust? The PI group will use GPS and INSAR to examine post-seismic transients and combine these with co-seismic data. They will combine many sources of GPS data (German - GFZ and US groups) that have been collected from 1993 to present over the entire orogen in an effort to develop a synoptic model. This includes data from 33 cGPS stations installed in Chile with NSF-RAPID funds immediately following the Maule earthquake. The regional extent of new analysis will include the rupture zone from the 1960 Mw 9.5 earthquake, which still shows post-seismic transient deformation. Among the important geodynamic processes that the project will address are (1) time-variable deformation in the aftermath of a great subduction-zone earthquake; (2) improved models of plate interface rheology and their implications for plate boundary earthquake cycles; and (3) interaction between plate boundary and intraplate deformation over time-scales from decadal to geological. In addition to GPS and InSAR observation of surface deformation, the project brings to bear a number of state-of-the-art observational and modeling approaches; earthquake location and source mechanism determination; geological and geochemical constraints on uplift and erosion rates; inversion for geometric and rheological parameters associated with the plate interface; and large-scale geodynamic modeling. The investigator team is highly qualified to take on these activities, and has a strong track record in previous work in the area. They have developed a strong set of collaborations, both in-country and with other international researchers working in the area.

该项目的总体目标是了解创建和现在驱动现代安第斯山脉演变的过程。 为了做到这一点，我们必须了解在板块界面处的耦合和软流圈的粘滞阻力作用下，在上板块中产生的应力的空间和时间变化。 具体而言，该项目将侧重于2010年智利马乌莱8.8级地震、沿纳斯卡-南美洲板块界面沿着的地震周期、安第斯系统的造山作用及其与地壳变形和地幔流动的关系。 该项目围绕两个主要主题展开：？巨型逆冲现象学如何影响或控制安第斯山脉从弧前到弧后的构造？?地质物质、浅部构造和板幔动力学如何影响或控制巨型逆冲断层的行为和演化？PI小组将使用全球定位系统和干涉合成孔径雷达检查地震后的瞬变，并将这些与同震数据联合收割机结合起来。他们将联合收割机结合1993年以来收集的许多GPS数据来源（德国---- GFZ和美国小组），以呈现整个造山带，努力发展一个天气模型。这包括马乌莱地震后立即在智利安装的33个cGPS站的数据。 新分析的区域范围将包括1960年Mw 9.5地震的破裂带，该破裂带仍显示出震后瞬时变形。该项目将研究的重要地球动力学过程包括：（1）俯冲带大地震后的时变变形;（2）改进的板块界面流变模型及其对板块边界地震周期的影响;（3）从十年到地质时间尺度上的板块边界和板内变形之间的相互作用。除了全球定位系统和干涉合成孔径雷达地表变形观测外，该项目还采用了一些最先进的观测和建模方法;地震定位和震源机制确定;地质和地球化学对隆起和侵蚀速率的制约;与板块界面有关的几何和流变参数反演;以及大规模地球动力学建模。调查员小组非常有资格开展这些活动，并在该领域以往的工作中有着良好的记录。他们在国内和与该领域的其他国际研究人员开展了一系列强有力的合作。