The 2016 Mw 7.8 Pedernales, Ecuador, Earthquake: Rapid Response Deployment
Stachnik, Joshua C.
Diego Mercerat, E.
AffiliationUniv Arizona, Dept Geosci
MetadataShow full item record
PublisherSEISMOLOGICAL SOC AMER
CitationAnne Meltzer, Susan Beck, Mario Ruiz, Mariah Hoskins, Lillian Soto‐Cordero, Joshua C. Stachnik, Colton Lynner, Rob Porritt, Daniel Portner, Alexandra Alvarado, Stephen Hernandez, Hugo Yepes, Philippe Charvis, Yvonne Font, Marc Regnier, Hans Agurto‐Detzel, Andreas Rietbrock, Sergio Leon‐Rios, E. Diego Mercerat; The 2016 Mw 7.8 Pedernales, Ecuador, Earthquake: Rapid Response Deployment. Seismological Research Letters ; 90 (3): 1346–1354. doi: https://doi.org/10.1785/0220180364
JournalSEISMOLOGICAL RESEARCH LETTERS
Rights© Seismological Society of America.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractThe April 2016 Pedernales earthquake ruptured a 100 km by 40 km segment of the subduction zone along the coast of Ecuador in an M-w 7.8 megathrust event east of the intersection of the Carnegie ridge with the trench. This portion of the subduction zone has ruptured on decadal time scales in similar size and larger earthquakes, and exhibits a range of slip behaviors, variations in segmentation, and degree of plate coupling along strike. Immediately after the earthquake, an international rapid response effort coordinated by the Instituto Geofisico at the Escuela Politecnica Nacional in Quito deployed 55 seismometers and 10 ocean-bottom seismometers above the rupture zone and adjacent areas to record aftershocks. In this article, we describe the details of the U.S. portion of the rapid response and present an earthquake cata-log from May 2016 to May 2017 produced using data recorded by these stations. Aftershocks focus in distinct clusters within and around the rupture area and match spatial patterns observed in long-term seismicity. For the first two and a half months, aftershocks exhibit a relatively sharp cutoff to the north of the mainshock rupture. In early July, an earthquake swarm occurred similar to 100 km to the northeast of the mainshock in the epicentral region of an M-w 7.8 earthquake in 1958. In December, an increase in seismicity occurred similar to 70 km to the northeast of the mainshock in the epicentral region of the 1906 earthquake. Data from the Pedernales earthquake and aftershock sequence recorded by permanent seismic and geodetic networks in Ecuador and the dense aftershock deployment provide an opportunity to examine the persistence of asperities for large to great earthquakes over multiple seismic cycles, the role of asperities and slow slip in subduction-zone megathrust rupture, and the relationship between locked and creeping parts of the subduction interface.
Note12 month embargo; published online: 6 March 2019
VersionFinal accepted manuscript
SponsorsNational Science Foundation (NSF) Rapid Response Research (RAPID) Program [EAR-1642498]; Portable Array Seismic Studies of the Continental Lithosphere (PASSCAL) facility of the Incorporated Research Institutions for Seismology (IRIS) through the PASSCAL Instrument Center at New Mexico Tech; NSF [EAR-1261681]; Department of Energy National Nuclear Security Administration; Instituto Geofisico at the Escuela Politecnica Nacional (IG-EPN) in Quito Ecuador; L'Institut de Recherche pour le Developpement (IRD) Geoazur at Universite de la Cote d'Azur France; Centre d'etudes et d'expertise sur les risques, l'environnement, la mobilite et l'amenagement (CEREMA) France; Natural Environment Research Council (NERC) in the United Kingdom