A Test of the Existence of the Eurasian - North American Plate Boundary on Sakhalin Island

库页岛欧亚-北美板块边界是否存在的检验

• 批准号: 0738629
• 负责人: Mikhail Kogan
• 金额: $ 2.81万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-01-15 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0738629&HistoricalAwards=false
• 关键词: Test; Existence; Eurasian; North; American

The configuration and motion of one of the largest lithospheric plates, North American, is very poorly understood in the large region of eastern Asia, where a wedge-like extremity of the North American plate is jammed between two larger plates, the Eurasian and Pacific plates. The main goal of this project is to determine if the North American and Eurasian plates converge on Sakhalin Island making 1000-km long plate boundary. The research relies on GPS surveys performed on Sakhalin between 1999 and 2006. Data from these surveys allow investigation of the strain accumulation on the island in terms of the viscoelastic crustal deformation at different stages of the earthquake cycle and, hence, to make a significant step forward in understanding the dynamics of the convergent plate boundary where subduction does not occur. The strain accumulation on Sakhalin Island is modeled at different stages of the earthquake cycle in order to determine if the velocity field is compatible with the Eurasia-North America relative motion or not. Discrepancies between GPS horizontal velocity vectors, earthquake slip vectors, and directions of relative plate motions in the southern Kuril Arc are being use in order to test whether the southern Kuril arc moves as predicted by the underthrusting of the Pacific plate beneath the North American plate or if there is a separate south Kuril sliver. The advantage of observations on Sakhalin is that the effect of the Pacific plate subduction on this island is small and can be reliably accounted for. Another advantage is that the system of faults on Sakhalin has been carefully mapped by geologic methods following the disastrous magnitude 7.0 (Mw) May 27, 1995 earthquake on northern Sakhalin.Unraveling and exploring the geometry, kinematics, and dynamics of interaction of such major plate as North America with adjacent plates in east Asia is an important problem in solid earth sciences. This problem has been debated for decades without much progress. This project is aimed at understanding the tectonics of the region neighboring one of the most densely populated countries, Japan. Sakhalin recently developed into the major supplier of oil and natural gas for eastern Asia. The oil and liquid natural gas pipelines run along the main Sakhalin fault, which is active seismically. Large disastrous earthquakes that killed thousands of people occurred on Sakhalin in the history and quite recently. This project will contribute to understanding the earthquake hazards in this part of the world.

最大的岩石圈板块之一北美板块的构造和运动在东亚广大地区人们知之甚少，北美板块的楔状末端被卡在两个较大的板块——欧亚板块和太平洋板块之间。该项目的主要目标是确定北美板块和欧亚板块是否在库页岛交汇，形成1000公里长的板块边界。该研究依赖于 1999 年至 2006 年间在萨哈林岛进行的 GPS 调查。这些调查数据可以根据地震周期不同阶段的粘弹性地壳变形来调查岛上的应变积累，从而在了解不发生俯冲的汇聚板块边界的动力学方面迈出重要一步。在地震周期的不同阶段对萨哈林岛的应变累积进行建模，以确定速度场是否与欧亚大陆-北美相对运动兼容。正在利用 GPS 水平速度矢量、地震滑移矢量和南千岛弧相对板块运动方向之间的差异来测试南千岛弧是否按照北美板块下方太平洋板块的俯冲所预测的那样移动，或者是否存在单独的南千岛条。对萨哈林岛进行观测的优点是太平洋板块俯冲对该岛的影响很小并且可以可靠地解释。另一个优点是，在1995年5月27日萨哈林岛北部发生7.0级（Mw）灾难性地震后，萨哈林岛的断层系统已通过地质方法仔细绘制。解开和探索北美等主要板块与东亚相邻板块相互作用的几何、运动学和动力学是固体地球科学中的一个重要问题。这个问题已经争论了几十年，但没有取得太大进展。该项目旨在了解人口最稠密的国家之一日本周边地区的构造。萨哈林岛最近发展成为东亚石油和天然气的主要供应地。石油和液化天然气管道沿着地震活跃的萨哈林岛主断层延伸。萨哈林岛历史上和最近都曾发生过导致数千人死亡的灾难性大地震。该项目将有助于了解世界这一地区的地震危害。