1D-velocity structure and seismotectonics of the Ecuadorian margin inferred from the 2016 Mw7.8 Pedernales aftershock sequence
1D-velocity structure and seismotectonics of the Ecuadorian margin inferred from the 2016 Mw7.8 Pedernales aftershock sequence
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根据 2016 年 Mw7.8 Pedernales 余震序列推断的厄瓜多尔边缘一维速度结构和地震构造
DOI：
10.1016/j.tecto.2019.228165
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发表时间：
2019
期刊：
影响因子：
2.9
通讯作者：
Hoskins, Mariah
中科院分区：
文献类型：
--
作者：
León-Ríos, Sergio;Agurto-Detzel, Hans;Rietbrock, Andreas;Alvarado, Alexandra;Beck, Susan;Charvis, Phillipe;Edwards, Benjamin;Font, Yvonne;Garth, Tom;Hoskins, Mariah
2016年4月16日，一场7.8级地震破坏了厄瓜多尔俯冲带的中央海岸段。地震发生后不久，厄瓜多尔国立理工学院地球物理研究所与几个国际机构一起部署了一个密集的临时地震网络，以便对地震后的余震序列进行准确分类。仪器包括短周期和宽带传感器，沿着海底地震仪。这一部署补充了厄瓜多尔常设地震网络，并记录了主震后一年内不断发展的余震序列。在2016年5月至8月期间手动挑选ML> 3.5的345个事件的子集，提供高度准确的P和S发作时间。从这个目录中，一个高质量的数据集的227个事件，与方位角差距<200°，同时反演，获得最小的一维速度模型的破裂区，沿着与震源位置和台站校正。我们观察到整个研究区域的平均Vp/Vs为1.82，相对较高的Vp/Vs值为1.95和2.18观察到最浅的层下降到7.5公里。在30 ~ 40 km的深度段，由于脱水和蛇纹化作用，相对Vp/Vs比值较高（1.93）。对于重新定位的地震活动性分布，事件群垂直于海沟排列，地壳地震活动也得到证实，沿着靠近海沟轴的地震。我们还计算了区域矩张量来分析主震后不同的地震活动来源。除了与俯冲过程有关的逆冲事件外，还检测到正常和走滑机制。我们认为，存在的俯冲海山来自卡内基海岭作为侵蚀剂，帮助创建一个场景，促进锁定，并允许地震活动延伸到海沟，沿着薄弱区大地震后激活。
On April 16th 2016 a Mw 7.8 earthquake ruptured the central coastal segment of the Ecuadorian subduction zone. Shortly after the earthquake, the Instituto Geofisico de la Escuela Politecnica Nacional of Ecuador, together with several international institutions deployed a dense, temporary seismic network to accurately categorize the post-seismic aftershock sequence. Instrumentation included short-period and broadband sensors, along with Ocean Bottom Seismometers. This deployment complemented the permanent Ecuadorian seismic network and recorded the developing aftershock sequence for a period of one year following the main-shock. A subset of 345 events with ML> 3.5, were manually picked in the period of May to August 2016, providing highly accurate P- and S-onset times. From this catalogue, a high-quality dataset of 227 events, with an azimuthal gap <200°, are simultaneously inverted for, obtaining the minimum 1D velocity model for the rupture region, along with hypocentral locations and station corrections. We observe an average Vp/Vs of 1.82 throughout the study region, with relatively higher Vp/Vs values of 1.95 and 2.18 observed for the shallowest layers down to 7.5 km. The high relative Vp/Vs ratio (1.93) of the deeper section, between 30 km and 40 km, is attributed to dehydration and serpentinization processes. For the relocated seismicity distribution, clusters of events align perpendicular to the trench, and crustal seismicity is also evidenced, along with earthquakes located close to the trench axis. We also compute Regional Moment Tensors to analyze the different sources of seismicity after the mainshock. Aside from thrust events related to the subduction process, normal and strike-slip mechanisms are detected. We suggest that the presence of subducting seamounts coming from the Carnegie Ridge act as erosional agents, helping to create a scenario which promotes locking and allows seismicity to extend up to the trench, along zones of weakness activated after large earthquakes.
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影响因子：
3.3
作者：
E. Sokos;J. Zahradník
通讯作者：
E. Sokos;J. Zahradník
厄瓜多尔中部俯冲带浅层慢滑事件引发强烈界面地震活动
DOI：
--
发表时间：
2013
期刊：
影响因子：
--
作者：
M. Vallée;J. Nocquet;J. Battaglia;Y. Font;M. Segovia;M. Régnier;P. Mothes;P. Jarrín;D. Cisneros;Sandro Vaca;H. Yepes;X. Martin;N. Béthoux;M. Chlieh
通讯作者：
M. Chlieh
影响因子：
2.9
作者：
Lonsdale, P
通讯作者：
Lonsdale, P
影响因子：
--
作者：
R. Collings;D. Lange;A. Rietbrock;F. Tilmann;D. Natawidjaja;B. Suwargadi;Matthew Miller;J. Saul
通讯作者：
R. Collings;D. Lange;A. Rietbrock;F. Tilmann;D. Natawidjaja;B. Suwargadi;Matthew Miller;J. Saul
影响因子：
2.8
作者：
Font, Yvonne;Segovia, Monica;Theunissen, Thomas
通讯作者：
Theunissen, Thomas