Article
Multidisciplinary Sciences
Joaquin Hormazabal, Marcos Moreno, Francisco Ortega-Culaciati, Juan Carlos Baez, Carlos Pena, Christian Sippl, Diego Gonzalez-Vidal, Javier Ruiz, Sabrina Metzger, Shoichi Yoshioka
Summary: This study investigates the spatiotemporal evolution of afterslip, seismicity, and locking following the 2015 Illapel earthquake using six years of continuous GNSS measurements. The results reveal that afterslip is concentrated in two zones surrounding the region of largest coseismic slip. The rapid relocking of the asperity experiencing the largest coseismic slip may explain the regular recurrence time of earthquakes in this region.
SCIENTIFIC REPORTS
(2023)
Article
Geochemistry & Geophysics
Arthur Frankel
Summary: This study analyzed strong-motion recordings of two large earthquakes in Chile to determine the rupture propagation and characteristics of high-frequency ground motions. The analysis revealed the distance and direction of the earthquake rupture, as well as the location and depth of the high-frequency subevents. It also developed a methodology to map the high-frequency source factors on the rupture zone. The results showed that the high-frequency subevents mainly occurred downdip of the peak slip of the earthquakes.
BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA
(2022)
Article
Geosciences, Multidisciplinary
Kai Liu, Jianghui Geng, Yangmao Wen, Francisco Ortega-Culaciati, Diana Comte
Summary: The study investigates the surface deformation and its relationship with aftershocks after the 2015 Illapel earthquake. The results show that the postseismic deformation is mainly concentrated around the hypocenter and gradually distributed to other areas over time. The occurrence of aftershocks may be related to these surface deformations.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Gabriel Easton, Jose Gonzalez-Alfaro, Angelo Villalobos, Gabriel Alvarez, Diego Melgar, Sergio Ruiz, Bernardo Sepulveda, Manuel Escobar, Tomas Leon, Juan Carlos Baez, Tatiana Izquierdo, Maximiliano Forch, Manuel Abad
Summary: On September 16, 2015, the M-w 8.3 Illapel megathrust earthquake caused unexpectedly high tsunami waves in the Coquimbo region, central-northern Chile. The geological response of the coast was complex and varied, influenced by nearby seismic patches. Additionally, evidence of prehistoric tsunamis suggests that these coasts have been exposed to both near and distant tsunamis.
SEISMOLOGICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
J. A. Ruiz, A. Perez, F. Ortega-Culaciati, E. Contreras-Reyes, D. Comte
Summary: The Mw 8.3 Illapel earthquake on September 16, 2015, had a rupture length of over 200 km along strike. Two large aftershocks occurred in close proximity and beyond the northern limit of the Illapel rupture. Kinematic rupture models showed that the first event had an updip propagation from the hypocenter and later a bilateral mode with large slip to the south. The second event relocated southwest and re-ruptured an area already broken by the first event. The spatial slip distribution of both events suggested slip in the usually aseismic upper portion of the megathrust.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2023)
Article
Geochemistry & Geophysics
Haozhe Yang, Rumeng Guo, Jiangcun Zhou, Hongfeng Yang, Heping Sun
Summary: Large earthquakes can cause changes in regional groundwater pressure, resulting in poroelastic rebound and observable surface deformation. By modeling the hydrologic response following the 2015 Illapel earthquake, it was found that fluid flows from the co-seismic high-slip region to the north and south sides, with stronger poroelastic effects in the north. Previous models overestimated the topography on both sides of the rupture zone and underestimated the middle region.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Cedric Twardzik, Mathilde Vergnolle, Anthony Sladen, Louisa L. H. Tsang
Summary: The study used GNSS data and an aftershock catalog to reveal the distinct behaviors of post-seismic slip and aftershocks following the 2015 Illapel earthquake in Chile. Post-seismic slip in the north was predominantly aseismic, while in the south aftershocks were the primary cause of post-seismic slip.
Article
Engineering, Marine
Jessica Rodwell, James H. Williams, Ryan Paulik
Summary: This study investigates the vulnerability of critical infrastructure to tsunamis by developing empirical fragility curves. The research reveals that culverts are the most vulnerable infrastructure component to tsunami damage. Compared to roads or utility poles, culverts, drain inlets, and railways are found to be more susceptible to destruction.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Environmental Studies
Hari Prasad Pandey, Kaushal Gnyawali, Kshitij Dahal, Narayan Prasad Pokhrel, Tek Narayan Maraseni
Summary: The 2015 Gorkha earthquake triggered numerous landslides in Nepal, leading to significant vegetation damage. The government attempted both artificial and self-ecological restoration, but the study found that the latter was more effective in recovering vegetation. Strict protection measures play a crucial role in promoting self-ecological restoration.
Article
Geochemistry & Geophysics
R. Tissandier, J. -M. Nocquet, E. Klein, C. Vigny, J. Ojeda, S. Ruiz
Summary: We used continuous and survey GNSS data to study the spatial and temporal evolution of afterslip following the 2015 Illapel earthquake. Our approach involved solving for incremental daily slip at the subduction interface using nonnegative least squares with spatial and temporal Laplacian regularization constraints. We found that afterslip occurred in specific areas surrounding the coseismic rupture, as well as within the rupture area itself. Our afterslip model showed strong correlations with aftershocks and repeating earthquakes, and we also observed localized afterslip triggered by specific aftershocks. We furthermore discovered enhanced aseismic slip correlated with a seismicity burst, and areas of enhanced afterslip correlated with previous seismic swarms.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Marie Bouih, Isabelle Panet, Dominique Remy, Laurent Longuevergne, Sylvain Bonvalot
Summary: Subduction zones megathrust faults are a major cause of the world's largest earthquakes. However, the role of deeper subduction processes in earthquake generation is poorly understood. In this study, the variations of the Earth's gravity gradients derived from GRACE geoid models are analyzed from 2003 to 2014. The analysis reveals a large-amplitude gravity gradient signal north of the epicentral area in the three months prior to the earthquake. The results suggest that these signals are related to mass redistributions within the solid Earth on the continental side of the subduction zone. The study highlights the importance of monitoring the Earth's time-varying gravity field to better understand the seismic cycle and dynamic processes in subduction zones.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Multidisciplinary Sciences
Benoit Derode, Raul Madariaga, Jaime Campos
Summary: The study analyzed the source mechanism of the Maule earthquake in South America and the seismic activity before and after the main shock. Through a unique seismic comparison method, they identified the seismic activity pattern before the main shock and the changes in seismic rate after the main shock. The study concluded that the earthquake was the result of multiple preparation stages increasing the locking degree at the plate interface and exhibiting irregular seismic activity at different time scales.
SCIENTIFIC REPORTS
(2021)
Article
Geosciences, Multidisciplinary
NicolaAlessandro Pino
Summary: The 28 December 1908 Messina Straits earthquake, one of the worst seismic disasters in history, still lacks a consensus on the causative fault and the assumption of significant subsidence preceding the event. However, a critical analysis of the available data rejects this assumption.
NATURAL HAZARDS AND EARTH SYSTEM SCIENCES
(2022)
Article
Geochemistry & Geophysics
Hideo Aochi, Sergio Ruiz
Summary: By applying kinematic and dynamic modeling to the 2015 Mw8.3 Illapel, Chile, earthquake, we were able to identify two ruptured patches, with a larger main patch in the north and a smaller patch in the south near the hypocenter. Dynamic rupture models showed that the initial rupture of the small hypocentral patch did not trigger the main patch due to a difference in fracture energy, leading to another nucleation event at depth.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geosciences, Multidisciplinary
Mark E. Kincey, Nick J. Rosser, Tom R. Robinson, Alexander L. Densmore, Ram Shrestha, Dammar Singh Pujara, Katie J. Oven, Jack G. Williams, Zuzanna M. Swirad
Summary: Research shows that in the 3.5 years following the 2015 Gorkha earthquake in Nepal, the number and area of landslides remained higher than on the day of the earthquake, with a systematic upslope and northward shift in landslide density. Areas where landslides persisted tended to cluster, while those that returned to pre-earthquake conditions were more dispersed.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2021)