Colorado Plateau/Rio Grande Rift/Great Plains Seismic Transect

EAR-0207812 Aster里奥格兰德裂谷地震断面(RISTRA)项目旨在利用一个特殊的数据集来研究美国西南部下面的地壳和地幔，该数据集包括来自德克萨斯州1000公里断面上57个站点的18个月的宽带远震IRIS PASSCAL数据，1999-2001年间记录的NM、AZ和UT。在国家科学基金会最初的资助下，完成了广泛的实地工作，在IRIS数据管理中心对数据进行了处理和存档，进行了初步分析，并向地球科学界和更广泛的社区传播。该项目继续对RISTRA进行分析，以前所未有的分辨率阐明和解释与里奥格兰德裂谷(RGR)、科罗拉多高原(CP)和大平原(GP)相关的结构和过程。主要目的是确定：(1)现今CP高海拔的支持性质；(2)与地表形态和构造有关的地幔过程的深度范围；(3)RGR区域之下地幔与地壳应变之间的联系；(4)法拉隆板块残余和任何可能分离的大陆岩石圈在地幔中的位置。利用接收函数方法进行的不连续面成像与横波分裂、三维地震层析成像、捕虏体和其他地质/地球物理约束的研究相结合，以揭示该地区约800公里深的结构。地震偏移处理技术正在应用，这些技术充分利用了Ristra实验的质量、长度和密集(~18公里)台站间距。弹性2-D和3-D建模工作正在与洛斯阿拉莫斯国家实验室和休斯顿大学合作，纳入美国能源部/SEG下一代建模(NGM)项目。

EAR-0207812 Aster The Rio Grande Rift Seismic Transect (RISTRA) project is designed to study the crust and mantle beneath the southwestern U.S. utilizing an exceptional data set consisting of 18 months of broadband teleseismic IRIS PASSCAL data from 57 sites along a 1000-km transect in TX, NM, AZ, and UT recorded during 1999-2001. Under initial NSF funding extensive fieldwork was completed, data were processed and archived at the IRIS data management center, and preliminary analysis was performed and disseminated to the earth science and broader communities. This project continues the analysis of RISTRA to illuminate and interpret structure and processes associated with the Rio Grande Rift (RGR), Colorado Plateau (CP), and Great Plains (GP) at unprecedented resolution. Principal goals are to determine the: (1) nature the support of the present high elevation of the CP; (2) depth extent of mantle processes associated with surface morphology and tectonics; (3) connection between mantle and crustal strain beneath the RGR region; (4) location in the mantle of remnants of the Farallon plate and any possible detached continental lithosphere. Imaging of discontinuities using receiver function methods is being coupled with studies of shear wave splitting, 3-D seismic tomography, xenolith, and other geological/geophysical constraints to reveal the structure of the region to depths of approximately 800 km. Seismic migration processing techniques that take full advantage of the quality, length, and dense (~18 km) station spacing of the RISTRA experiment are being applied. Elastic 2- and 3-D modeling efforts are being incorporated into the DOE/SEG Next Generation Modeling (NGM) Project in association with Los Alamos National Laboratory and the University of Houston.