Tsunami source of the 2011 Tohoku earthquake detected by an ocean-bottom magnetometer
Tsunami source of the 2011 Tohoku earthquake detected by an ocean-bottom magnetometer
复制标题
DOI：
10.1016/j.epsl.2013.09.015
复制
发表时间：
2013-11
影响因子：
5.3
通讯作者：
H. Ichihara;Y. Hamano;K. Baba;T. Kasaya
中科院分区：
文献类型：
--
作者：
H. Ichihara;Y. Hamano;K. Baba;T. Kasaya
通过检查位于日本海沟以东 50 公里处的海底电磁计的记录，确定了 2011 年 3 月 11 日东北地震（M 9.0）产生的海啸感应磁信号。垂直磁场分量的脉冲变化直接指示海啸波高和到达台站的时间。水平磁分量的脉冲变化表明海啸传播方向为东南偏东。这些数据表明，海啸源位于北纬约39.0°的日本海沟沿岸，距主破裂区东北约100公里。观测到的磁力变化和近海海平面数据的联合分析支持了这一震源位置，并表明海啸起源时间比地震起源时间晚约 1 分钟。此外，磁场变化和海平面变化表明源区在沟槽方向上拉长且宽度较窄。
Tsunami-induced magnetic signals resulting from the 11 March 2011 Tohoku earthquake (M 9.0) were identified from an examination of the record of an ocean-bottom electromagnetometer emplaced 50 km east of the Japan Trench. The impulsive variation of the vertical magnetic field component directly indicates the tsunami wave height and arrival time at the station. The impulsive variation of the horizontal magnetic components indicates east–southeast as the tsunami-propagation direction. These data indicate that the tsunami source was located along the Japan Trench at approximately 39.0°N latitude, which is about 100 km northeast from the main rupture area. Joint analysis of the observed magnetic variations and offshore sea-level data supports this source location and indicates that the tsunami origin time was about 1 min after the earthquake origin time. In addition, the magnetic field variation and the sea level change indicate that the source area was elongated in the trench direction and had a narrow width.