Phenomenology of deep slow earthquake family in southwest Japan
Phenomenology of deep slow earthquake family in southwest Japan
复制标题
日本西南部深部慢地震族现象学
DOI：
--
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
K. Obara
中科院分区：
文献类型：
--
作者：
K. Obara
[1]根据日本西南部俯冲板块界面深部慢震的时空特征，研究了它们的现象学特征，包括低频地震、甚低频地震和短期慢滑事件。地震的带状分布被分成几个部分，以间隙为界。震颤发作的重复性取决于发作的强度，而震颤发作的强度由每一发作中检测到的震颤次数来定义。重大地震事件与大量检测到的地震大约每隔6个月重复一次，并伴随着大段的短期慢滑事件。在较小的节段中，震颤次数较少的震颤发作的复发间隔为几个月。它们中的一些偶尔伴随着由小型慢滑事件引起的轻微地面倾斜。即使在同一节段，根据震颤发作的大小，也存在不同的复发间隔。运移模式在开始、终止、方向和速度上差异很大，但每一段的运移方向都有一个总的趋势。在缝隙的两侧，震动从缝隙旁边开始并传播到另一边。假设所有的地震事件都是由慢滑事件引起的，根据检测到的地震次数和每个地震事件的面积来估计等效的力矩和滑移量。从所有地震事件估计的等效滑动历史在每一段中几乎是恒定的。这表明震颤活动是慢滑的良好指标。
[1] The phenomenology of deep slow earthquakes, including low-frequency tremors, very low frequency earthquakes, and short-term slow slip events, on the subducting plate interface in southwest Japan is investigated on the basis of their spatiotemporal characteristics. The belt-like distribution of tremors is divided into segments bounded by gaps. The repetition of tremor episode depends on the magnitude of the episode, which is defined by the number of detected tremors within each episode. Major tremor episodes with a large number of detected tremors recur at an interval of approximately 6 months, accompanying the short-term slow slip events in large segments. In small segments, tremor episodes with small numbers of tremors have recurrence intervals of a few months. Some of them occasionally accompany the slight ground tilting caused by a small-size slow slip event. Even in the same segment, there exist different recurrence intervals according to the magnitude of the tremor episode. The migration pattern varies greatly in initiation, termination, direction, and speed; however, the migration direction has a general tendency for each segment. On both sides of the gap, the tremor starts next to the gap and propagates to the other side. Assuming all tremor episodes are caused by slow slip events, the equivalent moment and slip are estimated from the number of detected tremor counts and the area of each tremor episode. The equivalent slip history estimated from all tremor episodes is almost constant in each segment. This indicates that tremor activity is a good proxy for slow slips.