A 3-D Seismic Investigation of the Sediment-to-Rock Transition and Its Relationship to Nankai Subduction Thrust Seismicity: U.S.-Japan Collaborative Program

该奖项将支持一个地震反射、折射和被动地震活动项目，以研究日本东海岸南开海槽附近海洋地壳的逆冲作用。本实验要研究的主要特征是从海槽（海沟）的地震带到大陆边缘以下至少15公里深处的俯冲逆冲断层，在那里逆冲断层以显著的地震活动为标志。这项研究的目的是研究逆冲构造从地震表现到地震表现的变化过程中物理性质的变化。理解这种从压实和地震滑动到脆性破坏的转变是理解岩石圈消耗和地震动力学的一个主要未知问题。这个南开地震带标志着沿日本边缘的主要破坏性地震的位置。这个项目是一个合作实验。美国科学家将负责获取和解释来自逆冲断层和增生边缘的三维地震反射数据。日本同事将负责部署海底地震仪，用于地震折射和被动地震活动研究。除了从数据中获得基本的科学解释外，该实验对边际计划的发展至关重要，并将为国际海洋钻探计划的未来钻探提供必要的现场位置数据。＊＊＊

9730637 Bangs this award will support a seismic reflection, refraction and passive seismicity program to study underthrusting of oceanic crust along the Nankai Trough off the east coast of Japan. The primary feature to be examined in this experiment is the subduction thrust fault from its aseismic zone in the Trough (trench) to a depth of at least 15 kilometers beneath the continental margin where the thrust is marked by significant seismic activity. The goal of the study is to examine changes in physical properties along the thrust as it changes from aseismic to seismic expression. Understanding this transition from compaction and aseismic slip to brittle failure is a major unknown in understanding lithospheric consumption and earthquake dynamics. This Nankai seismogenic zone marks the location of major destructive earthquakes along the Japanese margin. The project is a collaborative experiment. United State scientists will be responsible for acquiring and interpreting 3-dimensional seismic reflection data from the thrust fault and accreting margin. Japanese colleagues will be responsible for deploying ocean bottom seismometers for seismic refraction and passive seismicity studies. In addition t the basic scientific interpretation to be derived from the data, the experiment is critical to the development of the MARGINS initiative and will provide necessary site location data for future drilling by the international Ocean Drilling Program. ***