Article
Multidisciplinary Sciences
Luis Astudillo-Sotomayor, Julius Jara-Munoz, Daniel Melnick, Joaquin Cortes-Aranda, Andres Tassara, Manfred R. Strecker
Summary: In the Liquirie-Ofqui Fault System in Southern Chile, a single fault segment has exhibited a rapid slip rate over the past millennia, indicating strain localization on the fault at millennial time scales but not sustained over longer time scales.
SCIENTIFIC REPORTS
(2021)
Article
Geosciences, Multidisciplinary
Paul Leon Goellner, Jan Oliver Eisermann, Catalina Balbis, Ivan A. Petrinovic, Ulrich Riller
Summary: The Southern Andes, traditionally considered as a classic example of kinematic partitioning of oblique plate convergence, is now challenged by recent studies that reveal more discontinuities and complexities in deformation structures.
INTERNATIONAL JOURNAL OF EARTH SCIENCES
(2021)
Article
Multidisciplinary Sciences
Gregory P. De Pascale, Melanie Froude, Ivanna Penna, Reginald L. Hermanns, Sergio A. Sepulveda, Daniel Moncada, Mario Persico, Gabriel Easton, Angelo Villalobos, Francisco Gutierrez
Summary: Research findings reveal that the geologic slip rates of the Liquine-Ofqui fault zone (LOFZ) are 11.6-24.6 mm/year (Quaternary) and 3.6-18.9 mm/year (Late-Cenozoic), and the distinct geochemistry of the Volcan Mate Grande (VMG) provides evidence for the slab window.
SCIENTIFIC REPORTS
(2021)
Article
Geology
Paulo Quezada, Francisco Herve, Mauricio Calderon, Mark Fanning, Robert Pankhurst, Estanislao Godoy, Octavio Urbina, Rodrigo Suarez
Summary: Undated low-grade metamorphic rocks in the Puerto Cisnes-Queulat area of Chile have been found to contain detrital zircons of mid-Oligocene age, with similar age and provenance as a paraconglomerate bed of the La Junta Formation to the north. Miocene plutonic rocks intruded these metasedimentary rocks, generating a contact metamorphic aureole and suggesting a regional pattern of earliest Neogene metamorphism and rapid exhumation in this segment of the Patagonian Andes.
Article
Geology
Rodrigo J. J. Suarez, Miguel E. E. Ramos, Christian Sue, Matias Ghiglione, Vanesa Barberon, Paulo Quezada, Sandrine Roy
Summary: Based on a compilation of strain/stress tensors and evidence of syntectonic strata, combined with a seismotectonic appraisal, typical features of faulting in the Patagonian Andes are assessed. The prevalence of strike-slip faulting challenges the classic proposal for alternating extensional and contractional deformation phases in the Andean orogen. Strain partitioning and non-partitioned contexts are suggested as explanations for the Cenozoic patterns of deformation in the North and South Patagonian Andes respectively.
INTERNATIONAL GEOLOGY REVIEW
(2023)
Article
Geosciences, Multidisciplinary
Jia Cheng, Xiwei Xu, Junjie Ren, Shimin Zhang, Xiyan Wu
Summary: The study analyzed the multi-segment rupturing characteristics of the Xiaojiang fault on the southeastern Tibetan Plateau, finding that historical rupture event models influence future seismic simulations, and determined the probability of multi-segment rupturing based on new geological mapping results.
JOURNAL OF ASIAN EARTH SCIENCES
(2021)
Article
Geochemistry & Geophysics
A. L. Stevens Goddard, J. C. Fosdick, M. Calderon, M. C. Ghiglione, R. A. VanderLeest, B. W. Romans
Summary: Thermochronologic data from zircon fission track and (U-Th)/He analysis in the southern Patagonian Andes reveal new patterns of Paleogene rock cooling and help reconstruct deformational and erosional events. The Path Family Approach is utilized to filter plausible thermal solutions based on structural and tectonic context. The results suggest a period of out-of-sequence deformation in the western domain and contemporaneous exhumation beyond the basin margins in the central domain, providing new insights into the tectonic evolution of the orogen.
Editorial Material
Geosciences, Multidisciplinary
Andrea Argnani
Summary: Dual-source modeling is essential for simulating the 1908 Messina tsunami event and should be based on geological constraints. In addition to the contribution of submarine landslides, it is also worth considering the potential tsunamigenic impact of secondary faults.
Article
Geosciences, Multidisciplinary
V. M. Montenegro, S. Spagnotto, D. Legrand, A. T. Caselli
Summary: The Caviahue caldera in South Chile is associated with both tectonic activity from the Liquine-Ofqui Fault System and volcanic activity. Studies have shown seismic clusters in the region with strike-slip faults from tectonic origin and normal faults from volcanic origin, particularly in the area near the active Copahue volcano.
BULLETIN OF VOLCANOLOGY
(2021)
Article
Geochemistry & Geophysics
J. T. Watt, M. L. McGann, R. K. Takesue, T. D. Lorenson
Summary: Distinguishing between seismic and aseismic fault slip in the geologic record is crucial for estimating the seismic potential of faults and the likelihood of multi-fault ruptures. This study integrated various methods to characterize vertical deformation and slip behavior within an extensional fault bend, providing important insights into seismic activity and the potential for multi-fault rupture.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geosciences, Multidisciplinary
Paraskevi Nomikou, Dimitris Evangelidis, Dimitrios Papanikolaou, Danai Lampridou, Dimitris Litsas, Yannis Tsaparas, Ilias Koliopanos
Summary: The study conducted a detailed analysis of the seafloor topography formed after the 2020 earthquake, revealing the presence of numerous landslides and canyons near Samos Island, indicating differences between the active tectonics characteristics and past tectonic features.
Article
Engineering, Geological
Mohammad Hassan Baziar, Mir Mahdi Rashedi
Summary: This research presents the pros and cons of two previous mitigation methods and proposes a novel method to reduce the foundation rotation caused by fault rupture. The results show that the new method is more effective in reducing foundation rotation, especially under unknown fault conditions.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2022)
Article
Geosciences, Multidisciplinary
Violeta Veliz-Borel, Vasiliki Mouslopoulou, Andrew Nicol, John Begg, Onno Oncken
Summary: This study focuses on the upper-plate normal faults along the forearc of the Hellenic Subduction System (HSS) in Greece. Detailed field-mapping and analysis of high-resolution Digital Elevation Models (DEMs) were used to study active normal faults on Kythira and Antikythira islands. The results show that these faults have different lengths and scarp heights, accommodating trench-orthogonal extension during the Quaternary. Rate variability between different time intervals and across the entire fault network suggests earthquake clustering may occur over relatively short timescales.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Environmental Sciences
Aitaro Kato, Shin'ichi Sakai, Satoshi Matsumoto, Yoshihisa Iio
Summary: Research indicates that young faults exhibit complex evolutionary characteristics, and fine structural complexities may impact seismic activity within fault zones. High-spatial-resolution images and a micro-earthquake catalog reveal the development of conjugate faults and earthquake cluster migration.
COMMUNICATIONS EARTH & ENVIRONMENT
(2021)
Article
Geochemistry & Geophysics
Luis Astudillo-Sotomayor, Joaquin Cortes-Aranda, Daniel Melnick, Julius Jara-Munoz, Catalina Cabello, Laura Perucca, Andres Tassara, Jose Vicente Perez-Pena, Pablo Leon-Ibanez
Summary: The seismic threat of intra-arc faults in the Southern Chile Subduction Zone should be considered due to their potential to produce moderate-to-large shallow earthquakes, causing severe damage to surrounding areas.
Article
Geochemistry & Geophysics
Cesar Pasten, Felipe Campos, Felipe Ochoa-Cornejo, Sergio Ruiz, Galo Valdebenito, David Alvarado, Felipe Leyton, Ricardo Moffat
Summary: The 1960 Valdivia earthquake in Chile was the largest recorded earthquake in modern times, with a rupture length close to 1000 km. Analysis of the city's geology and geophysical exploration results help explain the observed structural damage patterns caused by the earthquake. Soil characteristics and building types in Valdivia play a significant role in determining the extent of earthquake damage.
SEISMOLOGICAL RESEARCH LETTERS
(2021)
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
Geochemistry & Geophysics
E. Klein, B. Potin, F. Pasten-Araya, R. Tissandier, K. Azua, Z. Duputel, C. Herrera, L. Rivera, J. M. Nocquet, J. C. Baez, D. Zigone, R. Madariaga, J. P. Ampuero, S. Ruiz, C. Vigny
Summary: An earthquake sequence, including a mainshock of magnitude M-w = 6.9 followed by a M-w = 6.4 aftershock, occurred in the Atacama region of Chile in September 2020. Dynamic inversions show that the two largest earthquakes are located on the subduction interface. High rate GPS data allowed for the determination of instantaneous coseismic displacements and inference of coseismic slip models.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geosciences, Multidisciplinary
P. Poli, L. Cabrera, M. C. Flores, J. C. Baez, J. B. Ammirati, J. Vasquez, S. Ruiz
Summary: This study investigates a large and long-lived earthquake swarm occurring in the Bransfield Basin, a back-arc rift south of the South Shetland Islands, Antarctica. By analyzing the seismicity and geodetic deformation, the study suggests a volcanic origin for the earthquake swarm and reveals the involvement of transient deformation episodes at the ridge axial volcanic structure in the extensional processes.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
F. Pasten-Araya, B. Potin, K. Azua, M. Saez, F. Aden-Antoniow, S. Ruiz, L. Cabrera, J. P. Ampuero, J. M. Nocquet, L. Rivera, Z. Duputel
Summary: The along-dip influence of the Copiapo ridge subduction in the Atacama region, North-Central Chile was studied by analyzing a new seismicity catalog and obtaining a 3-D tomographic model. Four distinct segments were identified along the dip, with variations in velocity models indicating the presence of fluids coinciding with aseismic slip zones. These differences in seismogenic behavior are believed to be generated by the subduction of heterogeneous seamounts associated with the Copiapo ridge.
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
Geochemistry & Geophysics
Jean-Baptiste Ammirati, Antonio Villasenor, Sebastien Chevrot, Gabriel Easton, Maximilien Lehujeur, Sergio Ruiz, Maria Constanza Flores
Summary: In this study, a deep-learning approach is used to improve the detection of small-magnitude earthquakes in the South-Central Andes. The refined seismicity catalog aids in refining tomographic models and revealing a more detailed architecture of the Chilean forearc. The double-difference relocations of seismic events suggest a large-scale, west-dipping structure beneath the West Andean Thrust, contributing to crustal deformation and uplift over the past 20 million years.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Carlos Herrera, John F. Cassidy, Jan Dettmer, Efrain Rivera, Sergio Ruiz, Hannes Vasyura-Bathke
Summary: On September 10, 2008, a M-w 5.7 earthquake occurred in the Central Valley of northern Chile near the town of Pica. The earthquake had a high stress-drop and generated unusually high ground accelerations. The source properties indicate reverse-oblique fault motion on a plane dipping to the northeast, consistent with the dominant style of faulting in the region. Despite the lower occurrence rate of crustal events compared to interplate and inslab events, similar or larger magnitude crustal events have occurred approximately once every three years in northern Chile, posing a significant hazard to nearby populations or critical infrastructure.
SEISMOLOGICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
Thore F. F. Sager, Morelia Urlaub, Pauline Kaminski, Cord Papenberg, Galderic Lastras, Miquel Canals, Christian Berndt
Summary: Submarine landslides can cause destruction to seafloor infrastructures and trigger devastating tsunamis. This study re-analyzes a relatively small landslide near the Balearic Islands using high-resolution 3D reflection seismic data, providing detailed images of the landslide structure. The study reveals that the landslide is composed of source areas, translational domains, and deposition areas, with the rapid deposition deforming the underlying sediments. Additionally, the study suggests that the landslide evolved in two failure stages over tens of thousands of years.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geochemistry & Geophysics
Carlos Herrera, Francisco Pasten-Araya, Leoncio Cabrera, Bertrand Potin, Efrain Rivera, Sergio Ruiz, Raul Madariaga, Eduardo Contreras-Reyes
Summary: This study investigates the 2020 Calama earthquake sequence and compares it with other significant earthquakes in the area. The results show that the Calama main shock has similar stress drop and dynamic rupture parameters as the nearby Michilla and Jujuy earthquakes. The Calama sequence occurred in the upper lithospheric mantle with lower aftershock productivity and a less hydrated environment.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geosciences, Multidisciplinary
Javier Ojeda, Catalina Morales-Yanez, Gabriel Ducret, Sergio Ruiz, Raphael Grandin, Marie-Pierre Doin, Christophe Vigny, Jean-Mathieu Nocquet
Summary: The 2006 Copiapo swarm in Chile was characterized by several earthquakes and slow slip events. Seismological and geodetic analyses revealed that this swarm was driven by the subduction of the Copiapo Ridge seamounts, leading to complex interactions between seismic and aseismic processes at the plate interface and the overriding plate.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2023)
Article
Geochemistry & Geophysics
E. Klein, C. Vigny, Z. Duputel, D. Zigone, L. Rivera, S. Ruiz, B. Potin
Summary: Using survey GPS measurements, the first deep slow slip event (SSE) was detected in Chile in 2014-2016.5. Similar events had occurred twice before in 2006 and 2010, suggesting a 5-year repeat time. In anticipation of the next event expected for 2020, the existing continuous GNSS network in the region was densified with 5 new stations in early 2019. The SSE occurred in 2020 as expected, but was perturbed by the 2020 Atacama seismic sequence.
PHYSICS OF THE EARTH AND PLANETARY INTERIORS
(2023)
Article
Engineering, Geological
Jose Bustos, Cesar Pasten, Diego Pavez, Miguel Acevedo, Sergio Ruiz, Rodrigo Astroza
Summary: Results from multiple methods were combined to develop representative cross-sections of the Santiago Basin in Chile, providing information on geological features and wave velocities. Simulations of seismic responses revealed amplification of ground motions along basin edges and in softer deposits, indicating the importance of surface wave generation. The study also found that 2D effects were negligible in stiff gravel deposits and that 1D simulations could not accurately capture edge effects in fine-grained soils.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2023)
Article
Geosciences, Multidisciplinary
Christian Flores, Javier Ojeda, Cristian Otarola, Sebastian Arriola, Sergio Ruiz
Summary: Large intraplate intermediate-depth (IID) earthquakes in Chile are highly destructive to structures and have occurred throughout the country. While small and moderate IID earthquakes have been reported below Santiago in recent years, the possibility of large-magnitude events cannot be ruled out. This study investigates the strong ground motion generated by large-magnitude earthquakes below the Santiago metropolitan region, highlighting the importance of reproducing high-frequency time histories to reassess the seismic hazard.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2023)
Article
Geochemistry & Geophysics
Javier Ojeda, Sergio Ruiz
Summary: The first case of COVID-19 in Chile was confirmed on March 3, 2020, leading to mobility restrictions imposed by the Ministry of Health. Research shows strong similarities between anthropogenic seismic noise and human mobility indicators in major cities of Chile, reflecting the impact of public policies on urban mobility.