High‐resolution analysis of the gravest seismic normal modes after the 2004 Mw = 9 Sumatra earthquake using superconducting gravimeter data
High‐resolution analysis of the gravest seismic normal modes after the 2004 Mw = 9 Sumatra earthquake using superconducting gravimeter data
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DOI：
10.1029/2005gl023128
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发表时间：
2005-07
影响因子：
5.2
通讯作者：
S. Rosat;Tadahiro Sato;Y. Imanishi;J. Hinderer;Yoshiaki Tamura;Herbert McQueen;M. Ohashi
中科院分区：
文献类型：
--
作者：
S. Rosat;Tadahiro Sato;Y. Imanishi;J. Hinderer;Yoshiaki Tamura;Herbert McQueen;M. Ohashi
2004年12月26日发生的苏门答腊-安达曼MW > 9地震强烈激发了低频地震模式，这是改善最严重地震模式的频率和阻尼测量的独特机会。需要精确估计低于1 mHz的地震模式的频率分裂，以改进地球的一维密度模型。从这次事件中，2S 1是第一次观察到没有任何叠加的SG（超导重力仪）和地震记录。我们在这里报告了对从11个地点获得的SG数据的分析。SG记录的光谱清楚地表明，在个别台站，0 S2分裂成5个完全分辨的单线态，0 S3分裂成7个单线态。目前的结果表明，SG为低频地震模式的精确分析提供了高质量的数据。
The Mw > 9 Sumatra‐Andaman earthquake on December 26, 2004 has strongly excited the low‐frequency seismic modes and is a unique opportunity to improve the frequency and damping measurements of the gravest seismic modes. The precise estimation of the frequency splitting of the seismic modes below 1 mHz is needed to improve 1D‐density models of the Earth. From this event, 2S1 is observed for the first time without any stacking on both SG (Superconducting Gravimeter) and seismic records. We report here analyses of SG data obtained from 11 sites. The spectra of SG records clearly show the splitting of 0S2 into 5 completely resolved singlets and the splitting of 0S3 into 7 singlets at individual stations. The present results demonstrate that SGs provide high quality data for a precise analysis of the low‐frequency seismic modes.