NNSFGEO-NERC: Collaboration: The Role OF Asperities and Slow Slip in Subduction Zone Rupture and Aftershock Sequences: Insights from the 16 April 2016 Pedernales Ecuador Earthquake

NNSFGEO-NERC：合作：凹凸带和慢滑移在俯冲带破裂和余震序列中的作用：2016 年 4 月 16 日厄瓜多尔佩德纳莱斯地震的见解

• 批准号: 1723042
• 负责人: Anne Meltzer
• 金额: $ 24.49万
• 依托单位: Lehigh University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1723042&HistoricalAwards=false
• 关键词: NNSFGEO; NERC; Collaboration; Role; Asperities

The large faults that separate oceanic plates from continental plates in subduction zones generate the largest earthquakes and giant tsunami. Examples include earthquakes with magnitude 9.0 and larger in Chile in 1960, Alaska in 1964, Indonesia in 2004, and Japan in 2011. These giant earthquakes have significant economic and social impact causing loss of life and livelihoods, damage to buildings and infrastructure, disruption of business, and changes in communities that can take years for recovery. Modern instrumentation provides scientists the opportunity to study these faults and the earthquakes they generate in new ways. In April 2016, the Pedernales Earthquake ruptured the subduction zone along the coast of Ecuador in a large Mw 7.8 earthquake. An international rapid response effort deployed a seismic array to record aftershocks following this large earthquake that expanded long term observations of the national seismic and geodetic network in Ecuador. Analysis of these data provide an opportunity to link variations in structure and seismic properties along the subduction zone to the distribution of slip behaviors observed before, during, and after the earthquake. The broader impacts of this research have the potential to benefit society through improved hazard assessment and mitigation strategies for subduction zone earthquakes.A spectrum of fault slip behaviors (earthquakes, non-volcanic tremor, slow slip events, low-frequency earthquakes and very low-frequency earthquakes has been observed in a number of subduction zones globally. While a general framework has developed characterizing the variation in slip behaviors in the dip direction along the plate interface, a direct link between seismic properties and slip behavior and the relationship between slow-slip events and megathrust earthquakes has yet to be established. In April 2016, the Pedernales Earthquake ruptured an approximately 130 km long, 100 km wide segment of the subduction zone along the coast of Ecuador in a large Mw 7.8 megathrust event. Immediately after the earthquake a coordinated international rapid response effort deployed a seismic array (on land and offshore using ocean bottom seismometers, OBS) above the rupture zone and adjacent fault segments where large earthquakes occur on decadal time scales and slow slip events have been observed. The dense on land array combined with offshore OBS instruments provides an exceptional dataset to study the earthquake and aftershock sequence. The seismic array is complemented by rapid response geodetic efforts and long term observations from permanent national seismic and geodetic networks in Ecuador. The researchers will use subduction of the Nazca Plate beneath Ecuador and the Pedernales Earthquake and aftershock sequence to link along strike variations in structure and seismic properties to the distribution of slip behaviors observed (pre-, co- and post-seismic) to determine the relationship between slow slip and megathrust rupture. The integrated analyses from a variety of broadband seismic techniques will be used to examine the persistence of asperities for large to great earthquakes over multiple seismic cycles, the role of asperities in promoting or inhibiting rupture propagation, and the relationship between locked and creeping parts of the subduction interface. Broader impacts of this research will contribute to improved risk assessment from subduction zone earthquakes. In addition we are partnering with Build Change, a non-profit NGO, to develop materials to educate local communities on earthquake hazards and construction techniques to improve resiliency. This project supports academic research infrastructure in seismology and computation, and professional development and training for early career scientists. Results from this research will be integrated into STEM education at both the graduate and undergraduate level.This project is cofunded by the Office of International Science and Engineering.

The large faults that separate oceanic plates from continental plates in subduction zones generate the largest earthquakes and giant tsunami.例子包括1960年智利的地震9.0和更大的地震，1964年的阿拉斯加，2004年的印度尼西亚和2011年的日本。这些巨大的地震具有重大的经济和社会影响，导致生命和生计丧失，建筑物和基础设施的损害，对业务的破坏，商业的破坏以及可以带来多年恢复社区的变化。现代仪器为科学家提供了研究这些断层和以新方式产生的地震的机会。 2016年4月，Pedernales地震破裂了厄瓜多尔海岸的俯冲带，在大型MW 7.8地震中破裂。一项国际快速的反应努力部署了地震阵列，以记录这场大地震后的余震，扩大了厄瓜多尔国家地震和大地测量网络的长期观察。对这些数据的分析提供了一个机会，可以将俯冲带的结构和地震特性的变化与地震之前，期间和之后观察到的滑移行为的分布联系起来。这项研究的更广泛的影响通过改善俯冲带的危险评估和缓解策略来使社会受益。断层行为的频谱（地震，非vollcanic震颤，慢速倾斜事件，较低的频率事件，低频频率地震和极低的频率地震在多种多样的范围内都构成了一般的zones框架，这是一般范围内的范围。沿板界面的浸入方向，地震特性与滑动行为之间的直接联系，慢滑圈事件与大型地震之间的关系尚未在2016年4月建立。在破裂区和相邻的断层段上方部署了一个地震阵列（使用海底地震米在陆地和近海上），在这些断层区域和相邻的断层段中已经观察到大地震发生在十年时间尺度上，并且已经观察到慢速滑移事件。陆地阵列上的密集与海上观察器仪器相结合，提供了一个出色的数据集来研究地震和余震序列。地震阵列与厄瓜多尔永久性的民族地震和大地测量网络的快速响应作用和长期观察相辅相成。研究人员将使用厄瓜多尔和佩德纳尔地震和余震序列的纳斯卡板的俯冲来沿结构和地震特性的打击变化与观察到的滑移行为的分布（前，共同和后震动）的分布联系，以确定慢速滑移和巨型肌肉破裂之间的关系。来自各种宽带地震技术的综合分析将用于检查大地震至巨大地震在多个地震周期上的持久性，阳离子在促进或抑制破裂传播中的作用以及俯冲界面的锁定部分和蠕动的部分之间的关​​系。这项研究的更广泛的影响将有助于改善俯冲带地震的风险评估。此外，我们还与非营利性非政府组织的Build Change合作，开发材料，以教育当地社区有关地震危害和建筑技术以提高弹性。该项目支持地震学和计算中的学术研究基础设施，以及早期职业科学家的专业发展和培训。 这项研究的结果将纳入研究生和本科级别的STEM教育中。该项目由国际科学与工程办公室进行。

项目成果

The 2016 Mw 7.8 Pedernales, Ecuador, Earthquake: Rapid Response Deployment

2016 年厄瓜多尔 7.8 级佩德纳莱斯地震：快速响应部署

• DOI: 10.1785/0220180364
• 发表时间: 2019
• 期刊: Seismological Research Letters
• 影响因子: 3.3
• 作者: Meltzer, Anne;Beck, Susan;Ruiz, Mario;Hoskins, Mariah;Soto‐Cordero, Lillian;Stachnik, Joshua C.;Lynner, Colton;Porritt, Rob;Portner, Daniel;Alvarado, Alexandra
• 通讯作者: Alvarado, Alexandra

1D-velocity structure and seismotectonics of the Ecuadorian margin inferred from the 2016 Mw7.8 Pedernales aftershock sequence

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
• 发表时间: 2019
• 期刊: Tectonophysics
• 影响因子: 2.9
• 作者: León-Ríos, Sergio;Agurto-Detzel, Hans;Rietbrock, Andreas;Alvarado, Alexandra;Beck, Susan;Charvis, Phillipe;Edwards, Benjamin;Font, Yvonne;Garth, Tom;Hoskins, Mariah
• 通讯作者: Hoskins, Mariah

3D Local Earthquake Tomography of the Ecuadorian Margin in the Source Area of the 2016 Mw 7.8 Pedernales Earthquake

2016 年 Mw 7.8 佩德纳莱斯地震震源区厄瓜多尔边缘的 3D 局部地震层析成像

• DOI: 10.1029/2020jb020701
• 发表时间: 2021
• 期刊: Journal of Geophysical Research: Solid Earth
• 作者: León‐Ríos, Sergio;Bie, Lidong;Agurto‐Detzel, Hans;Rietbrock, Andreas;Galve, Audrey;Alvarado, Alexandra;Beck, Susan;Charvis, Philippe;Font, Yvonne;Hidalgo, Silvana
• 通讯作者: Hidalgo, Silvana

Structure of the Ecuadorian forearc from the joint inversion of receiver functions and ambient noise surface waves

接收器函数和环境噪声表面波联合反演的厄瓜多尔前弧结构

• DOI: 10.1093/gji/ggaa237
• 发表时间: 2020
• 期刊: Geophysical Journal International
• 影响因子: 2.8
• 作者: Koch, Clinton D;Lynner, Colton;Delph, Jonathan;Beck, Susan L;Meltzer, Anne;Font, Yvonne;Soto-Cordero, Lillian;Hoskins, Mariah;Stachnik, Josh C;Ruiz, Mario
• 通讯作者: Ruiz, Mario

Structural Control on Megathrust Rupture and Slip Behavior: Insights From the 2016 Mw 7.8 Pedernales Ecuador Earthquake

• DOI: 10.1029/2019jb018001
• 发表时间: 2020-02
• 期刊: Journal of Geophysical Research: Solid Earth
• 作者: L. Soto‐Cordero;A. Meltzer;E. Bergman;M. Hoskins;J. Stachnik;H. Agurto‐Detzel;A. Alvarado;S. Beck;P. Charvis;Y. Font;G. Hayes;S. Hernández;C. Lynner;S. León‐Ríos;J. Nocquet;M. Régnier;A. Rietbrock;F. Rolandone;M. Ruiz