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

该项目的总体目标是了解创造和现在推动现代安第斯山脉演变的过程。为了做到这一点，我们必须了解由板块界面耦合和软流层粘性阻力在上板产生的应力的时空变异性。具体而言，该项目将重点关注2010年智利8.8级Maule地震、纳斯卡-南美板块界面地震周期、安第斯系统造山作用及其与地壳变形和地幔流动的关系。该项目围绕两个主题：？大逆冲现象学如何影响或控制安第斯造山运动从弧前到弧后的构造？吗?地质物质、浅层构造和板块/地幔动力学如何影响或控制巨型逆冲构造的行为和演化？PI小组将使用GPS和INSAR来检查震后瞬态，并将这些数据与同震数据结合起来。他们将结合从1993年至今在整个造山带收集的许多GPS数据来源（德国- GFZ和美国小组），努力开发一个天气模型。这包括Maule地震发生后由NSF-RAPID基金在智利安装的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，该破裂带仍然显示震后瞬态变形。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旋回的影响；(3)从年代际到地质的时间尺度上，板块边界与板内变形的相互作用。除了对地表变形的GPS和InSAR观测外，该项目还采用了一些最先进的观测和建模方法；地震定位与震源机制确定；地质和地球化学对隆升和侵蚀速率的制约；与板界面相关的几何和流变参数的反演；以及大规模地球动力学建模。调查小组非常有资格承担这些活动，并且在该领域以前的工作中有着良好的记录。他们在国内以及与在该领域工作的其他国际研究人员开展了一系列强有力的合作。

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.