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.

在东亚的大片地区，人们对最大的岩石圈板块之一北美板块的构造和运动知之甚少，北美板块的楔状末端夹在欧亚板块和太平洋板块这两个更大的板块之间。该项目的主要目标是确定北美板块和欧亚板块是否会聚在库页岛形成1000公里长的板块边界。这项研究依赖于1999年至2006年间在库页岛进行的GPS调查。这些调查的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，因此，在理解没有发生俯冲的收敛板块边界的动力学方面迈出了重要的一步。为了确定库页岛的速度场是否与欧亚-北美的相对运动相适应，对库页岛地震周期不同阶段的应变积累进行了模拟。GPS水平速度矢量、地震滑动矢量和南千岛岛弧相对板块运动方向之间的差异被用来检验南千岛岛弧的运动是否如太平洋板块在北美板块下方的逆冲所预测的那样，或者是否存在一个单独的南千岛岛弧。在库页岛观测的优点是太平洋板块俯冲对该岛的影响很小，可以可靠地解释。另一个优点是，1995年5月27日库页岛北部发生7.0级（Mw）灾难性地震后，通过地质方法对库页岛的断层系统进行了仔细的测绘。揭示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。这个问题已经讨论了几十年，但没有多大进展。该项目旨在了解邻近人口最稠密的国家之一日本的地区构造。库页岛最近发展成为东亚石油和天然气的主要供应国。石油和液化天然气管道沿着地震活跃的库页岛主断层运行。在历史上和最近，库页岛发生了造成数千人死亡的灾难性大地震。这个项目将有助于了解这个地区的地震灾害。