Collaborative Research: An Integrated Tectonic Study of the Jamaica Strike-slip Restraining Bend and Gonave Microplate Using GPS, Geomorphologic, Seismic, and Gravity Data

威斯康星大学和得克萨斯大学的一个科学家研究小组正在对加勒比海岛国牙买加进行为期四年的综合地球物理和地质研究，该岛国横跨一个主要的走滑断层，该弯曲是由于加勒比-北美板块在戈纳韦银色板块南北边界之间的分割而形成的。新的大地测量、地貌测量、古地震测量、重力测量和地震测量正在结合起来：(1)测量牙买加附近的加勒比海板块运动，以建立整个岛屿的完整断层滑动预算，以及相对于加勒比海和北美板块的Gonave微板块运动；(2)通过地貌、古地震和目标重力研究的结合，建立牙买加主要活动断层的位置、滑动感觉和长期滑动速率；(3)建立和测试断层滑移率的正演和反演模型，以区分提出的关于错动断层链之间滑动传递的模型，并改进在这个人口稠密和地震多发的国家中的地震危险性评估，使用所有测量的限制；(4)将结果与来自伊斯帕尼奥拉的GPS站点速度相结合，得出一个与所有数据完全一致的Gonave微板块运动模型。该项目应能更好地了解牙买加的地震风险，自1600年以来，牙买加经历了两次破坏性地震，由于地震能量集中和该国南部大部分人口稠密和经济重要的松散冲积层的液化，牙买加仍然容易受到重大地震破坏。这些测量应提供关于各种空间和时间尺度的地震周期的有用信息，包括首都金斯敦附近的芭蕉园断层的千年地震历史和潜力，以及该岛所有地区正在积累的地震间弹性应变的年度预算。这项研究将与牙买加地震网络合作进行，牙买加地震网络负责地震台网运行、地震研究以及地震危险评估和响应。

An integrated, four-year geophysical and geological study of the Caribbean island of Jamaica, which straddles a major strike-slip fault restraining bend that has formed in response to partitioning of Caribbean-North America plate motion between the northern and southern boundaries of the Gonave sliver plate, is being carried out by a research team of scientists from the University of Wisconsin and the University of Texas. New geodetic, geomorphologic, paleoseismic, gravity, and seismic measurements are being combined to: (1) measure Caribbean plate motion near Jamaica to establish the full fault slip budget across the island and Gonave microplate motion relative to the Caribbean and North American plates; (2) establish the locations, slip senses, and long-term slip rates along major active Jamaican faults through a combination of geomorphologic, paleoseismologic, and targeted gravity studies; (3) construct and test forward and inverse models of fault slip rates, to distinguish between proposed models for how slip is transferred between the offset fault strands, and to improve earthquake hazard assessment in this densely populated and earthquake-prone country use constraints from all measurements; (4) combine results with GPS site velocities from Hispaniola to derive a model for Gonave microplate motion that is fully consistent with all the data.This project should provide a better understanding of earthquake hazard in Jamaica, which has experienced two destructive earthquakes since 1600 and continues to be vulnerable to significant earthquake damage due to seismic energy focusing and liquefaction of unconsolidated alluvium in much of the heavily populated and economically important southern half of the country. The measurements should provide useful information about the earthquake cycle over range of spatial and temporal scales, including the millenial-scale seismic history and potential of the Plantain Garden fault near the capital city of Kingston to the year-to-year budget of interseismic elastic strain that is accumulating in all areas of the island. The research will be done in collaboration with the Jamaican Seismological Network, which is responsible for seismological network operation, seismic research, and earthquake hazard assessment and response.