Toward Improved Models of Caribbean Plate Motion and Non-Rigidity and the Neotectonics of Jamaica: Continuation of Caribbean Global Positioning System Measurements

将在牙买加、洪都拉斯和西加勒比的圣安德烈斯岛进行全球定位系统测量，主要目标有两个：（1）改进目前加勒比板块运动的初步模型，使之能够检验这个狭窄板块内部的假设变形，（2）与牙买加地震台网主任/地震学家Margaret Grandison合作，继续对牙买加新构造和地震灾害进行较新的研究。为实现第一个目标，将重新启用牙买加南部和洪都拉斯最近安装的全球定位系统纪念碑，以及圣安德烈斯岛的一个关键全球定位系统基准。加勒比板块内部目前只有一个有效的全球定位系统基准，在板块内部西部1 500公里处，全球定位系统覆盖范围的扩大将大大提高加勒比板块角速度的微弱超定精度，并将允许对板块内部的可测量变形进行更严格的测试。为实现第二个目标，将把最近安装的由14个地点组成的牙买加全球定位系统网络内的全球定位系统测量结果与牙买加地震网络的地震结果结合起来，以模拟这个贫穷而人口稠密的国家的地震危险和新构造，该国的两个最大城市金斯顿和蒙特哥湾都建在历史上发生过大地震的断层附近。使用地震约束的断层位置，断层倾角和地震滑动方向，调查人员将使用GPS速度来解决岛上弹性应变积累的位置和大小的界限。_________________________________________________________________________

DeMets 0003550 GPS measurements in Jamaica, Honduras, and San Andres island in the western Caribbean will be undertaken, with two principal goals: (1) To improve the still-rudimentary models of present-day Caribbean plate motions to a level capable of testing for hypothesized deformation within the interior of this narrow plate, and (2) To continue a relatively new study of Jamaican neotectonics and seismic hazard in collaboration with Margaret Grandison, the director/seismologist of the Jamaican Seismographic Network (JSN). Toward the first goal, recently-installed GPS monuments in southern Jamaica and Honduras will be reoccupied, as will a critical GPS benchmarks on San Andres Island. Improved GPS coverage of the Caribbean plate interior, which presently has only one active GPS benchmark in the western 1500 km of the plate interior, will significantly improve the accuracy of the weakly over-determined Caribbean plate angular velocity and will allow more rigorous tests for measurable deformation of the plate interior. Toward the second goal, GPS measurements within a recently installed 14-site Jamaican GPS network will be combined with seismic results from the JSN to model seismic hazard and neotectonics of this poor and densely-populated country, whose two largest cities Kingston and Montego Bay are built near faults that have had large historic earthquakes. Using seismically-constrained fault locations, fault dips, and earthquake slip directions, the investigators will use GPS velocities to solve for bounds on the location and magnitude of elastic strain accumulation on the island. _________________________________________________________________________