Coseismic velocity change associated with the 2011 Van earthquake (M7.1): Crustal response to a major event
Coseismic velocity change associated with the 2011 Van earthquake (M7.1): Crustal response to a major event
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DOI：
10.1002/2014gl060624
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发表时间：
2014-07-16
影响因子：
5.2
通讯作者：
Kartal, Recai
中科院分区：
文献类型：
--
作者：
Acarel, Digdem;Bulut, Fatih;Kartal, Recai
监测同震速度变化是一项重大挑战，因为必须使用重复的活动源或天然源在震前、同震和震后阶段对地壳进行统一采样。在这里，我们使用环境噪声研究 2011 年凡/土耳其地震的地壳响应，这提供了最佳的时间分辨率。对最近五个宽带站的 6 个月时间段内的综合记录进行了分析，确定了主要冲击。我们观察到，在 0.05-0.3 Hz 频率范围内，主震附近的同震速度下降了 0.76%。速度降在靠近震源处最大，并随着距离的增加而系统地减小。我们还发现同震速度降低与破裂面上同震滑移量之间存在相关性。观察到的速度下降显示了脆性地壳对大地震的剧烈反应。
Monitoring coseismic velocity changes is a major challenge, since the Earth crust has to be uniformly sampled at preseismic, coseismic, and postseismic stages using repeating active or natural sources. Here we investigate the crustal response to the 2011 Van/Turkey earthquake using ambient noise, which provides the best possible temporal resolution. Combined recordings from the nearest five broadband stations are analyzed for a time period of 6 months framing themain shock. We observe a coseismic velocity decrease of up to 0.76% in the vicinity of the main shock in the frequency range of 0.05-0.3 Hz. The velocity drop is largest at close proximity to the earthquake hypocenter and decreases systematically with distance. We also find a correlation between coseismic velocity decrease and the amount of coseismic slip on the rupture plane. The observed velocity drop shows the drastic response of the brittle crust in response to a major earthquake.