Tsunami source of the 2004 Sumatra-Andaman earthquake inferred from tide gauge and satellite data
Tsunami source of the 2004 Sumatra-Andaman earthquake inferred from tide gauge and satellite data
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DOI：
10.1785/0120050613
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发表时间：
2007-01-01
影响因子：
3
通讯作者：
Satake, Kenji
中科院分区：
文献类型：
--
作者：
Fujii, Yushiro;Satake, Kenji
2004年苏门答腊-安达曼地震的海啸源是通过验潮仪记录的海啸波形和卫星测高测量捕获的海面高度的联合反演来估计的。这场地震是过去40年来最大的一次，对印度洋周围的国家造成了毁灭性的海啸破坏，但海啸源，特别是其北方端，并没有得到很好的解决。虽然余震和地壳变形从苏门答腊岛西北部延伸到尼科巴群岛和安达曼群岛，但一些地震波分析表明震源长度较短，只有几百公里。我们使用的海啸波形记录在12个验潮站周围的源和三个卫星测量的海面高度：Jason]，TOPEX/Poseidon，和Envisat。我们使用真实的水深测量对海啸传播进行了数值计算;从海图中数字化了66，000多个深度点，并与ETOP 02数据相结合。卫星数据的反演表明，海啸源延伸到安达曼群岛，总长度为1 400公里，但这种模型产生的海啸波形比印度验潮站观测到的要大得多。验潮仪记录的反演和联合反演表明，海啸源约为900公里长。最大的滑动，约13至25米，位于苏门答腊岛附近，第二大滑动，高达7英寸，靠近尼科巴群岛。对于不同的破裂速度和上升时间，滑移分布是相似的，其中1 km/sec的慢速和3 min的上升时间产生最大的方差减少。
Tsunami source of the 2004 Sumatra-Andaman earthquake was estimated from a joint inversion of tsunami waveforms recorded on tide gauges and sea surface heights captured by satellite altimetry measurements. The earthquake, the largest in the past 40 years, caused devastating tsunami damage to countries around the Indian Ocean, but the tsunami source, in particular, its northern end, was not well resolved. Although aftershocks and crustal deformation extended from off northwestern Sumatra Island through the Nicobar Islands to the Andaman Islands, some seismic-wave analyses indicated a shorter source length, several hundred kilometers. We used tsunami waveforms recorded at 12 tide gauge stations around the source and the sea surface heights measured by three satellites: Jason], TOPEX/Poseidon, and Envisat. We numerically computed tsunami propagation using realistic bathymetry; more than 66,000 depth points were digitized from nautical charts and combined with the ETOP02 data. Inversion of satellite data indicates that the tsunami source extended to the Andaman Islands with a total length of 1,400 km, but such a model produces much larger tsunami waveforms than observed at Indian tide gauge stations. Inversion of tide gauge records and the joint inversion indicate that the tsunami source was about 900 kin long. The largest slip, about 13 to 25 m, was located oft Sumatra Island and the second largest slip, up to 7 in, near the Nicobar Islands. The slip distribution is similar for different rupture velocities and rise times, with a slow velocity of 1 km/sec and a rise time of 3 min yielding the largest variance reduction.