Collaborative Research: Rio Grande Rift II - Kinematics and Dynamics of Continental Deformation in Low Strain-Rate Environments

合作研究：Rio Grande Rift II - 低应变率环境下大陆变形的运动学和动力学

• 批准号: 1053596
• 负责人: Anne Sheehan
• 金额: $ 19.77万
• 依托单位: University of Colorado at Boulder
• 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: 2011-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1053596&HistoricalAwards=false
• 关键词: Collaborative; Research; Rio; Grande; Rift

The Rio Grande Rift Global Positioning System (GPS) network consists of 25 GPS monuments installed throughout Colorado and New Mexico in 2006 and 2007. Initial results combined with other continuous GPS data suggest that the deformation pattern across the Rio Grande Rift and adjacent physiographic provinces is broadly distributed and is not focused on the surficial expression of the rift. Given that this is a low strain-rate environment, long observing times are needed, and the Rio Grande Rift GPS network is being transferred to UNAVCO for longer-term observations. In addition to estimating uniform site velocities with the Rio Grande Rift GPS data, strain components and rigid-body rotations are being determined to better characterize the nature of the distributed deformation. The vertical component of deformation is being assessed, which the longer time-series are beginning to be able to resolve. USArray Transportable Array seismic data are being used to study seismicity and earthquake source parameters along the Rio Grande Rift and in surrounding regions. Improved earthquake locations will be determined using regional velocity models and advanced location algorithms. Full waveform moment tensor inversion is being used to determine earthquake source parameters. Special care is going into determining hypocenter depth, stress drop, and earthquake slip vectors. Project broader impacts include education and involvement of two graduate students, participation by faculty in SAGE (Summer of Applied Geophysical Experience), assessment of a GPS in-class exercise for introductory geology courses, and conversion of 5 GPS monuments to permanent stations for the broad geodetic community.

格兰德河裂谷全球定位系统（GPS）网络由2006年和2007年在整个科罗拉多和新墨西哥州安装的25个GPS纪念碑组成。初步结果结合其他连续GPS数据表明，变形模式横跨格兰德河裂谷和邻近的地文省广泛分布，并不集中在裂谷的地表表达。鉴于这是一个低应变率的环境，需要长时间的观测，格兰德河裂谷全球定位系统网络正在移交给联刚特派团进行长期观测。除了用格兰德河裂谷GPS数据估计统一的场地速度外，还确定了应变分量和刚体旋转，以更好地描述分布变形的性质。正在评估变形的垂直部分，较长的时间序列开始能够解决这个问题。USArray移动式阵列地震数据正被用于研究沿着格兰德河裂谷和周围地区的地震活动和震源参数。将使用区域速度模型和先进的定位算法来确定更好的地震位置。全波形矩张量反演正被用于确定震源参数。要特别注意确定震源深度、应力降和地震滑动矢量。项目的更广泛影响包括两名研究生的教育和参与，教师参加SAGE（应用地球物理经验之夏），评估地质学入门课程的GPS课堂练习，以及将5个GPS纪念碑转换为广泛的大地测量界的永久站。