2011年日本东北地区近海大地震板块边界滑动带的地质构造和物质组成

• 作 者: F M Chester C Rowe K Ujiie J Kirkpatrick C Regalla F Remitti J C Moore V Toy M Wolfson-Schwehr S Bose J Kameda J J Mori E E Brodsky N Eguchi S Toczko 343和343T 勘查队科技人员 王林
• 机 构: Center for Tectonophysics,Department of Geology and Geophysics,Texas A&M University,College Station,
• 出 处: 国际地震动态
• 发表日期: 2015年08期
• 关键词: 板块边界 滑动带 海洋钻探 俯冲带 随钻测井 日本东北 反射解释 俯冲板块 粘土层 粘土含量

俯冲带大地震的机理受到板块边界断层的摩擦性质、地质构造和物质组成的影响。通过利用综合海洋钻探计划(Integrated Ocean Drilling Program,IODP)343和343T勘探结果,我们观测到2011年日本东北地区近海地震和海啸的较浅断层的地质构造和物质组成。随钻测井和岩心采样观测结果表明,在该钻探点,单个的主要板块边界断层与日本东北地区近海地震破裂的大型滑动相吻合,且与附近几乎所有累积的板内运动相一致。深海粘土有限厚度(小于5m)的局部形变被认为是浅层地震断层的特征,表明深海粘土可能在区域尺度上控制着海啸地震。

The mechanism of the subduction zone large earthquake is affected by the frictional properties, geological structure and material composition of the plate boundary faults. Using the 343 and 343T exploration results of the Integrated Ocean Drilling Program (IODP), we observed the geological structure and material composition of the shallower fault of the 2011 offshore northeastern Japan earthquake and tsunami. LWD and core sampling observations show that at this drilling site a single major plate boundary fault coincides with a large slip of the offshore seismic break in northeastern Japan and is consistent with nearly all accumulated intraplate motion in the vicinity. The localized deformation of deep sea clay with a finite thickness (less than 5 m) is considered as a feature of shallow seismic faults, suggesting that deep-sea clays may control tsunami earthquakes on a regional scale.