Collaborative Research: A GPS Study of Caribbean Plate Kinematics and Distributed Deformation Between the Caribbeanand North American Plates

9806464 Mandarin项目是NSF资助的一项长期工作的延续，该工作旨在测量加勒比板块的现今运动，并确定刚性板块运动沿伊斯帕尼奥拉岛和波多黎各附近的加勒比-北美板块边界沿着的适应方式。 这些目标包括：（1）利用从横跨加勒比板块的地点获得的全球定位系统速度建立加勒比板块运动学模型，并利用同样的速度检验加勒比板块的非刚性;（2）确定加勒比-北美运动如何被分离伊斯帕尼奥拉岛和波多黎各附近两个板块的断层分割，最终，通过模拟弹性应变和从速度场提取块体旋转来提取关于该板块边界的动力学的信息;（3）确定了伊斯帕尼奥拉岛北方Septentrional断层的滑动速率和弹性应变积累水平，尽管地质证据表明在过去的几千年里发生了重大滑动，但700多年来没有经历过大地震。 在1986年、1994年和1995年建立了一个跨越加勒比-北美板块边界的全球定位系统网络，为确定应能解决这些问题的场地位移奠定了基础，现在已经过去了足够的时间，因此在重新定位网络内发生了额外的可测量的位移（范围从10-100毫米）。 拟议的工作将包括重新占用现有场地以及网络的密集化和适度扩大。

9806464MannThis project is a continuation of a long-term NSF-sponsed effort to measure the present-day motion of the Caribbean plate and to determine the manner in which rigid plate motion is accommodated along the Caribbean-North America plate boundary near Hispaniola and Puerto Rico. The objectives include: (1) Construction of a Caribbean plate kinematic model using GPS-derived velocities from sites that span the Caribbean plate and to use the same velocities to test for non-rigidity of the Caribbean plate; (2) determination of how Caribbean-North America motion is partitioned by the faults that separate the two plates in the vicinity of Hispaniola and Puerto Rico, and ultimately, to extract information about the dynamics of this plate boundary by modeling elastic strain and extracting block rotations from the velocity field; (3) determination of the slip rate and level of elastic strain accumulation along the Septentrional fault in northern Hispaniola, which has not experienced a major earthquake in more than 700 years despite geologic evidence for significant slip over the past several thousand years. Occupations in 1986, 1994, and 1995 of a GPS network spanning the Caribbean-North America plate boundary have set the stage for determinations of site displacements that should resolve these questions, and sufficient time has now elapsed so that additional measurable (ranging from 10-100 millimeters) displacements have occurred within the exisiting network. The proposed work will include a reoccupation of the existing sites as well as densification and modest expansion of the network.