Three‐Dimensional Modeling of Spontaneous and Triggered Slow‐Slip Events at the Hikurangi Subduction Zone, New Zealand
Three‐Dimensional Modeling of Spontaneous and Triggered Slow‐Slip Events at the Hikurangi Subduction Zone, New Zealand
复制标题
新西兰希库朗伊俯冲带自发和触发慢滑事件的三维建模
DOI：
10.1029/2019jb018190
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
T. Matsuzawa
中科院分区：
文献类型：
--
作者：
B. Shibazaki;L. Wallace;Y. Kaneko;I. Hamling;Y. Ito;T. Matsuzawa
在新西兰希库兰吉南部边缘，长期(持续1年)、深部(25公里)的慢滑事件(SSE)大约每隔5年发生一次。相比之下，沿Hikurangi北部和中部边缘，短期和浅(<；10公里)SSE(持续2至3周)每隔1至2年发生一次。然而，目前还不清楚是什么控制了上交所行为的这些差异。在这项研究中，我们使用板块边界的三维模型来模拟整个Hikurangi俯冲带上的SSE，该模型结合了速率和状态摩擦定律以及截止速度对演化的影响。总体而言，我们的模型能够在Hikurangi边缘复制SSE行为的沿走向和深度变化。我们的模型还表明，在地震间隔期的后半段，随着孕震带深部滑动速度的增加，深部、长期SSE的滑动速度也会增加。通过在上证所地区施加Kaikōura地震引起的静态应力变化，我们还再现了地震后深层、长期SSE的触发模式。我们的结果进一步表明，通过静态应力传递触发SSE的倾向取决于扰动的幅度和相对于SSE循环的时间。总体而言，与浅层短期事件(~1兆帕)相比，自发性和触发式SSE对深层、长期事件(~5兆帕)需要更大的有效应力值。如此低的有效应力可以用这些SSE源区存在的高孔隙流体压力来解释。
At the southern Hikurangi margin, New Zealand, long‐term (duration of >1 year), deep (>25 km) slow‐slip events (SSEs) occur at intervals of approximately 5 years. In contrast, along the northern and central Hikurangi margin, short‐term and shallow (<10 km) SSEs (2‐ to 3‐week duration) occur at 1‐ to 2‐year intervals. However, it is not clear what controls these differences in SSE behavior. In this study, we simulate SSEs along the entire Hikurangi subduction zone using a 3‐D model of the plate boundary incorporating a rate‐and‐state friction law with a cutoff velocity to the evolution effect. Overall, our models are able to replicate the along‐strike and depth‐dependent variations in SSE behavior at the Hikurangi margin. Our models also show that the slip velocities of the deep, long‐term SSEs increase when the slip velocities at the deeper extension of the seismogenic zone increase during the latter half of the interseismic period. By imposing static stress changes induced by the Kaikōura earthquake in the SSE regions, we also reproduce patterns of triggering of deep, long‐term SSEs that followed the earthquake. Our results further suggest that the propensity for SSE triggering via static stress transfer depends on the amplitude of perturbation and the timing with respect to the SSE cycle. Overall, both spontaneous and triggered SSEs require larger values of effective stress for deep, long‐term events (~5 MPa) compared to the shallow, short‐term events (~1 MPa). Such low effective stresses can be explained by the existence of high pore fluid pressure in these SSE source regions.
影响因子：
18.3
作者：
Wallace, Laura M.;Kaneko, Yoshihiro;Fry, Bill
通讯作者：
Fry, Bill
影响因子：
13.6
作者：
Ikari MJ;Kopf AJ
通讯作者：
Kopf AJ