Seeber L, Armbruster JG
Lamont-Doherty Earth Observatory, Palisades, New York 10964, USA.
Nature. 2000 Sep 7;407(6800):69-72. doi: 10.1038/35024055.
Aftershocks occurring on faults in the far-field of a large earthquake rupture can generally be accounted for by changes in static stress on these faults caused by the rupture. This implies that faults interact, and that the timing of an earthquake can be affected by previous nearby ruptures. Here we explore the potential of small earthquakes to act as 'beacons' for the mechanical state of the crust. We investigate the static-stress changes resulting from the 1992 Landers earthquake in southern California which occurred in an area of high seismic activity stemming from many faults. We first gauge the response of the regional seismicity to the Landers event with a new technique, and then apply the same method to the inverse problem of determining the slip distribution on the main rupture from the seismicity. Assuming justifiable parameters, we derive credible matches to slip profiles obtained directly from the Landers mainshock. Our results provide a way to monitor mechanical conditions in the upper crust, and to investigate processes leading to fault failure.
大地震破裂远场断层上发生的余震通常可由破裂引起的这些断层上的静态应力变化来解释。这意味着断层之间存在相互作用，且地震的发生时间会受到先前附近破裂的影响。在此，我们探讨小地震作为地壳力学状态“灯塔”的潜力。我们研究了1992年发生在南加州的兰德斯地震所引发的静态应力变化，该地区因众多断层而地震活动频繁。我们首先用一种新技术评估区域地震活动对兰德斯地震的响应，然后将相同方法应用于从地震活动确定主破裂面上滑动分布的反问题。假设参数合理，我们得出了与直接从兰德斯主震获得的滑动剖面的可靠匹配结果。我们的结果提供了一种监测上地壳力学状况以及研究导致断层破裂过程的方法。
