Great (≥Mw8.0) megathrust earthquakes and the subduction of excess sediment and bathymetrically smooth seafloor
Great (≥Mw8.0) megathrust earthquakes and the subduction of excess sediment and bathymetrically smooth seafloor
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大（≥Mw8.0）巨型逆冲地震以及过量沉积物和测深平滑海底的俯冲
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
E. Geist
中科院分区：
文献类型：
--
作者：
D. Scholl;S. Kirby;R. Huene;H. Ryan;R. Wells;E. Geist
[Ruff (1989)][1] 使用较旧且部分有缺陷的数据表明，进入俯冲带 (SZ) 的厚沉积物平滑并加强了板间耦合的海沟平行分布。据推测，这种情况有利于破裂的延续和高震级（≥Mw8.0）板间逆冲（IPT）地震的产生。使用更大、更准确的沉积物厚度和仪器（1899年至2013年1月）和前仪器时代（1700-1898）IPT（分别为n = 176和12）的汇编，我们测试了≥Mw7.5的IPT地震发生地点与进入SZ的厚（≥1.0 km）和薄（≤1.0 km）沉积部分之间是否存在令人信服的关系。
根据新的汇编，可以得出统计支持的声明（参见摘要和结论），即高震级地震最容易在沉积良好的 SZ 中形成核。例如，尽管厚沉积物海沟的全球长度缩短了 7500 公里，但它们占仪器时代 IPT ≥Mw8.0 的~53%、~75% ≥Mw8.5 和 100% ≥Mw9.1。没有>Mw9.0的巨型逆冲断层在薄沉积物海沟处破裂，而在厚沉积物海沟处发生了三个破裂（1960年智利Mw9.5、1964年阿拉斯加Mw9.2和2004年苏门答腊岛Mw9.2）。
然而，大的 Mw8.0–9.0 IPT 通常 (n = 23) 在薄沉积物沟槽中成核。这些地震与低起伏海底的俯冲有关，俯冲侵蚀的碎片使板块分离的俯冲通道变厚。据推测，低测深起伏和俯冲侵蚀的结合也产生了耦合的平滑海沟平行分布，有利于高震级 IPT 地震的特征性长期破裂。在这些地区，弱沉积层序的俯冲进一步使破裂得以延续。
[1]：#ref-81
Using older and in part flawed data, [Ruff (1989)][1] suggested that thick sediment entering the subduction zone (SZ) smooths and strengthens the trench-parallel distribution of interplate coupling. This circumstance was conjectured to favor rupture continuation and the generation of high-magnitude (≥Mw8.0) interplate thrust (IPT) earthquakes. Using larger and more accurate compilations of sediment thickness and instrumental (1899 to January 2013) and pre-instrumental era (1700–1898) IPTs (n = 176 and 12, respectively), we tested if a compelling relation existed between where IPT earthquakes ≥Mw7.5 occurred and where thick (≥1.0 km) versus thin (≤1.0 km) sedimentary sections entered the SZ.
Based on the new compilations, a statistically supported statement (see Summary and Conclusions) can be made that high-magnitude earthquakes are most prone to nucleate at well-sedimented SZs. For example, despite the 7500 km shorter global length of thick-sediment trenches, they account for ∼53% of instrumental era IPTs ≥Mw8.0, ∼75% ≥Mw8.5, and 100% ≥Mw9.1. No megathrusts >Mw9.0 ruptured at thin-sediment trenches, whereas three occurred at thick-sediment trenches (1960 Chile Mw9.5, 1964 Alaska Mw9.2, and 2004 Sumatra Mw9.2).
However, large Mw8.0–9.0 IPTs commonly (n = 23) nucleated at thin-sediment trenches. These earthquakes are associated with the subduction of low-relief ocean floor and where the debris of subduction erosion thickens the plate-separating subduction channel. The combination of low bathymetric relief and subduction erosion is inferred to also produce a smooth trench-parallel distribution of coupling posited to favor the characteristic lengthy rupturing of high-magnitude IPT earthquakes. In these areas subduction of a weak sedimentary sequence further enables rupture continuation.
[1]: #ref-81
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影响因子：
18.3
作者：
Satish C. Singh;N. Hananto;Maruf Mukti;David P. Robinson;Shamita Das;A. Chauhan;H. Carton;B. Gratacos;Stephan Midnet;Y. Djajadihardja;H. Harjono
通讯作者：
Satish C. Singh;N. Hananto;Maruf Mukti;David P. Robinson;Shamita Das;A. Chauhan;H. Carton;B. Gratacos;Stephan Midnet;Y. Djajadihardja;H. Harjono
影响因子：
18.3
作者：
M. Moreno;C. Haberland;O. Oncken;A. Rietbrock;S. Angiboust;O. Heidbach
通讯作者：
M. Moreno;C. Haberland;O. Oncken;A. Rietbrock;S. Angiboust;O. Heidbach
影响因子：
64.8
作者：
Schurr, Bernd;Asch, Guenter;Vilotte, Jean-Pierre
通讯作者：
Vilotte, Jean-Pierre
莫克兰俯冲带的热结构和巨型逆冲孕震潜力
影响因子：
5.2
作者：
Smith G
通讯作者：
Smith G