Gabriel Easton

Gabriel Easton
University of Chile · Departamento de Geología

PhD

About

148
Publications
39,476
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Introduction
Geologist, MSc. Geology and PhD in Oceanography. I’m an Earth scientist specialized in Quaternary and Marine Geology, working on paleoseismology and active tectonics, paleoclimate of extreme alluvial episodes, geo-archaeology and geological hazards. I'm mostly interested on environmental processes, sustainable development, Earth and humankind.

Publications

Publications (148)
Article
Full-text available
Early inhabitants along the hyperarid coastal Atacama Desert in northern Chile developed resilience strategies over 12,000 years, allowing these communities to effectively adapt to this extreme environment, including the impact of giant earthquakes and tsunamis. Here, we provide geoarchaeological evidence revealing a major tsunamigenic earthquake t...
Article
Full-text available
In the South-Central Andes, the crustal structures driving the tectonic evolution of the Andean Cordillera remain unresolved. So far, most seismological studies focused on the subduction interface, leaving crustal seismicity and its relationship with crustal deformation and Andean volcanism mostly unconstrained. However, because of their large numb...
Article
On 16 September 2015, the Mw 8.3 Illapel megathrust earthquake broke the subduction contact of the Nazca plate beneath the South American plate, causing unexpectedly high tsunami waves that strongly impacted the coast along the Coquimbo region in central–northern Chile. Here, we report results from a postearthquake and tsunami survey, evidencing a...
Article
The Andes Cordillera of central Chile is one of the most active mountain ranges on the Earth, where tectonics and volcanism strongly imprint its Quaternary landscape evolution, and superficial processes, such as catastrophic mass movements, modulate it. This article addresses the genesis and flow mechanisms of a massive rock avalanche deposit in th...
Article
Full-text available
La Falla San Ramón se ubica a los pies del borde occidental de la cordillera de los Andes, a lo largo del piedemonte andino situado al oriente del valle Santiago. Constituye una fractura o zona de debilidad en la corteza terrestre, capaz de acumular esfuerzo tectónico y deslizar un bloque cortical respecto de otro, generando sismos superficiales. D...
Article
Full-text available
Santiago, territorio y amenaza de la Falla San Ramón. Sobre la importancia de la consideración de las fallas activas para la sostenibilidad de nuestras comunidades. Geohuellas 4, 19-22. https://geologia-ambiental.cl/geohuellas/numero-4/santiago-territorio-y-amenaza-de-la-falla-san-ramon/
Article
Full-text available
A lo largo de las costas del Desierto de Atacama los sitios arqueológicos del Pleistoceno tardío-Holoceno temprano son escasos, ligados, en el norte de Chile, al complejo cultural Huentelauquén. Si bien este desierto costero constituye una de las regiones más áridas de nuestro planeta, la riqueza y vastedad del mar aledaño, junto a condiciones loca...
Article
Full-text available
Santiago ha experimentado en sus últimas décadas un aumento considerable de áreas urbanizadas en el piedemonte de su borde oriente, donde además se localiza la Falla San Ramón (FSR), de modo que se ha vuelto un nuevo escenario de riesgo geológico. Usando incuestionables atractivos sobre el medio natural, la vista panorámica a la ciudad y un ambient...
Article
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The southernmost portion of the Liquiñe-Ofqui fault zone (LOFZ) lies within the proposed slab window which formed due to oblique subduction of the Chile Ridge in Patagonia. Mapping of paleo-surface ruptures, offsets, and lithological separations along the master fault allowed us to constrain geologic slip rates for the first time with dextral rates...
Article
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The aim of this project was to establish past variations in the main oceanographic and climatic features of a transitional semiarid ecosystem on the north-central Chilean coast. We analyzed recent sedimentary records retrieved from two bays, Guanaqueros and Tongoy (30∘ S), for geochemical and biological analyses, including the following: sensitive...
Article
The coastal Atacama Desert is exposed to strong earthquakes and giant tsunamis associated with the subduction of the Nazca plate beneath the South American plate. Nevertheless, historical and geological records of tsunamis and paleotsunamis in this region are scarce. Taltal (25.4 S) is located at the southern edge of the hyperarid Atacama Desert wi...
Article
Extreme precipitation events and multi-annual droughts, especially in arid to semi-arid subtropical regions, are among the most critical El Niño Southern Oscillation (ENSO) and global climate change impacts. Here, we assess the variability of torrential rainfall during the Late Holocene and its projection into the 21st century at the southern edge...
Book
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¿Qué necesita saber una comunidad que ha vivido un desastre socionatural para poder transformarlo en una oportunidad para vivir mejor? El 25 de marzo de 2015 (25M) la fuerza de voluntad de las comunidades de Atacama fue puesta a prueba una vez más cuando severos aluviones, provocados por un evento de intensas lluvias, bajaron por las quebradas afec...
Poster
Full-text available
In Central Chile between 33º and 34º, most of the recorded seismicity is related to the subduction of the Nazca plate (and subsequent intra-slab deformation), under the South American plate. To the east, a much smaller fraction of the regional seismicity (~ 5%) is observed at shallow level (0-30 km) beneath the western flank of the Principal Cordil...
Poster
Full-text available
A escala de tiempo geológico, la posición y los movimientos verticales de la costa son considerados como efectos de primer orden del contacto de placas en zonas de subducción (Wesson et al., 2015). Sin embargo, la relación entre la deformación vertical de corto plazo producida por terremotos y el alzamiento costero de largo plazo en el norte de Chi...
Conference Paper
Full-text available
Se presenta el estudio de la fauna de foraminíferos bentónicos realizado en sedimentos de fondo oceánico holocenos de la Bahía de Guanaqueros, Región de Coquimbo, Chile. En total, se han encontrado individuos de 52 especies distintas, agrupadas en 29 géneros y 4 órdenes. Las especies más representadas son Bolivina seminuda, Nonionella auris, Cancri...
Conference Paper
Full-text available
Flujos de barro e inundaciones gatillados por eventos extremos de lluvia han generado terribles desastres en diversas localidades del Desierto de Atacama. Basados en el análisis de datos meteorológicos y crónicas del siglo XX, el estudio de sedimentos marinos de la Bahía de Tongoy (30°S), y modelos de simulación climática hemos evaluado los factore...
Article
Full-text available
This study aims at establishing past variations of the main oceanographic and climatic features in the Central Chilean coast, using recent sedimentary records of a transitional semi-arid ecosystem susceptible to environmental forcing conditions. Coquimbo (30°S) region is characterized by dry summers and short rainfall periods during winter. The rel...
Article
Over long-term geological scales, the position and vertical movements of the coast are considered to be among the most important effects resulting from first-order plate tectonics interactions in the subduction zones. However, the relationship between short-term vertical deformation driven by earthquakes and long-term coastal uplift in the Andean s...
Article
Full-text available
Santiago, capital city of Chile inhabited by ca. 7 million persons (INE, 2018), is located at the foot of the western flank of the main Andes Cordillera, which is one of the most active mountain chains worldwide. The eastern border of the city, located at the piedmont of the mountain front, experienced an accelerated urbanization in the last four d...
Preprint
Full-text available
West-verging thrusts, synthetic with the Nazca - South America subduction interface, have been recently discovered at the western front of the Andes. At ~33°30’S, the active San Ramón fault stands as the most frontal of these west-verging structures, and represents a major earthquake threat for Santiago, capital city of Chile. Here we elaborate a d...
Poster
Full-text available
In Central Chile, most of the recorded seismicity is linked with the subduction of the Nazca plate and associated intra-slab deformation, under the South American plate. More to the east, a much smaller portion of the regional seismicity (~ 5%) is related to thrusting deformation of the western cordilleran front of the south Central Andes. Although...
Conference Paper
Full-text available
The forearc region of the Central Andes is characterized by active faults. Nevertheless, the submarine cartography and activity of these faults are almost unknown. Here, we report late Pleistocene-Holocene surface deformation and active submarine normal faulting on the continental shelf of the northern Mejillones Peninsula. Trough differential GPS...
Article
Full-text available
In this paper, we present recent data on Early Holocene human occupations from Taltal, in the coast of the Atacama Desert. We focus on evidences of mobility and subsistence economy, discussing the data in terms of a concept of territoriality adapted from cultural geographers working with hunting-gathering societies. We attempt to show that the Huen...
Poster
Full-text available
Mejillones Peninsula, in Northern Chile, presents one of the best-preserved sets of beach-ridges of the Chilean coast. This coastal deposit comprises more than 300 beach-ridges from 20 up to 200 masl. The two last big earthquakes that affected the area resulted in the uplifting of the coast up to ~80 cm [1]. Thus, the study of this beach-ridges seq...
Chapter
The September 16, 2015 Illapel, Chile earthquake triggered a large tsunami, causing both economic losses and fatalities. To study the coastal effects of this earthquake, and to understand how such hazards might be accurately modeled in the future, different finite fault models of the Illapel rupture are used to define the initial condition for tsun...
Article
Full-text available
West-verging thrusts, synthetic with the Nazca - South America subduction interface, have been recently discovered at the western front of the Andes. At ~33°30’S, the active San Ramón fault stands as the most frontal of these west-verging structures, and represents a major earthquake threat for Santiago, capital city of Chile. Here we elaborate a d...
Article
Full-text available
On 16 September 2015, the M w 8.3 Illapel, Chile, earthquake broke a large area of the Coquimbo region of north-central Chile. This area was well surveyed by more than 15 high-rate Global Positioning System ( GPS ) instruments, installed starting in 2004, and by the new national seismological network deployed in Chile. Previous studies had shown th...
Conference Paper
Full-text available
The Mejillones Peninsula – located at the continental active margin of the Central Andes, northern Chile – is a first order geomorphic feature characterized by uplifted Pleistocene marine terraces and beach-ridges. Based on radiocarbon and Optically Stimulated Luminescence results, we dated marine deposits located up to 21 m a.s.l. as 31 – 46 ka, w...
Article
The September 16, 2015 Illapel, Chile earthquake triggered a large tsunami, causing both economic losses and fatalities. To study the coastal effects of this earthquake, and to understand how such hazards might be accurately modeled in the future, different finite fault models of the Illapel rupture are used to define the initial condition for tsun...
Article
Full-text available
The 2015 Mw8.3 Illapel, Chile earthquake is the latest megathrust event on the central segment of that subduction zone. It generated strong ground motions and a large (up to 11m runup) tsunami which prompted the evacuation of more than 1 million people in the first hours following the event. Observations during recent earthquakes suggest that these...
Conference Paper
Full-text available
The Mejillones Peninsula is a first order morphostructural feature located at the active margin of northern Chile, in the Central Andes external forearc, where part of the continental shelf has been uplifted. Conspicuous Pleistocene marine terraces and paleo beach-ridges evidence this uprising. In this geomorphic and tectonic setting it has been di...
Conference Paper
Full-text available
On April 21, 2007 an earthquake of magnitude 6.2 Mw hit the Aysén region in southern Chile. This event corresponds to the largest magnitude earthquake in an earthquake sequence (called the Aysén Seismic Crisis) that began to be felt from January 10 with a small earthquake of magnitude ML <3 and continued until February 2008. This area is characteri...
Conference Paper
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El 21 de abril del año 2007 un sismo de magnitud Mw 6.2 azotó la Región de Aysén en el sur de Chile. Este evento corresponde al sismo de mayor magnitud de una secuencia de terremotos (denominada Crisis Sísmica de Aysén) que comenzaron a sentirse desde el 10 de enero con un pequeño sismo de magnitud ML < 3 y que continúo hasta febrero del 2008. Esta...
Research
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Wepresent reconstructions of late Holocene changes in the source of organicmatter and siliceous export production in the Relocanví Fjord (41°S, 72°W),Northern Chilean Patagonia, based on organic carbon content, δ13Corg, N/ C ratio, diatomassemblages and biogenic silica contents fromthree sediment cores. The age models are based on a combination of...
Article
We present reconstructions of late Holocene changes in the source of organic matter and siliceous export production in the Relocanví Fjord (41°S, 72°W), Northern Chilean Patagonia, based on organic carbon content, δ13Corg, N/C ratio, diatom assemblages and biogenic silica contents from three sediment cores. The age models are based on a combination...
Article
The Atacama region in northern Chile hosts the driest desert on Earth and is the world’s premier iodine production province. The origin of iodine enrichment in Atacama is controversial and fundamentally different processes have been invoked over the years that involve marine, aeolian and more recently deep sedimentary fluid and groundwater sources....
Article
This work presents the results of a regional-scale estimation of low-enthalpy geothermal resources for district heating in the Santiago basin. The purpose of this work is to identify promising areas for the development of this type of renewable energy. The estimation was based on comparison of soil thermal properties and hydrogeological parameters,...
Conference Paper
Full-text available
The Mejillones Peninsula (23ºS) is an anomalous geomorphologic and tectonic feature along the subduction margin of the Central Andes, characterized by Quaternary uplifted littoral ridges, marine terraces and active crustal faults. It lies at the southern edge of the Northern Chile seismic gap, where the last large event Mw~8.8 occurred on 1877. The...
Poster
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The Aysén fjord, 65 km long and east-west oriented, is located at 45.4ºS and 73.2ºW in Chilean Patagonia. It has a maximum water depth of 345 m. It collects the inputs of Aysén, Pescado, Condor and Cuervo rivers, which drain the surrounding Patagonian Andes. The fjord is crossed by the Liquiñe-Ofqui Fault Zone, a seismically active trench parallel...
Article
Full-text available
Estimating the potential for the occurrence of large earthquakes on slow-slip-rate faults in continental interiors, away from plate boundaries, is possible only if the long-term geological record of past events is available. However, our knowledge of strong earthquakes appears to be incomplete for thrust faults flanking large actively growing mount...
Article
Full-text available
Lithic particles in marine laminated sediments provide the opportunity to reconstruct ocean-climate processes like wind dynamics from the sedimentary record. In Mejillones Bay (23º S), located on the hyperarid coast of the Atacama Desert, marine laminated sediments record paleoceanographic variations related to coastal upwelling and regional South...
Article
Full-text available
The crustal-scale west-vergent San Ramón thrust fault system, which lies at the foot of the main Andean Cordillera in central Chile, is a geologically active structure with manifestations of late Quaternary complex surface rupture on fault segments along the eastern border of the city of Santiago. From the comparison of geophysical and geological o...
Conference Paper
Full-text available
The Aysén fjord is a 65 km long, east-west oriented fjord in Chilean Patagonia, located approximately at 45.4ºS and 73.2ºW, with a maximum water depth of 345 m. The fjord receives at present the riverine input of Aysén, Pescado, Condor and Cuervo rivers, which drain the surrounding up to 2000 m high Patagonian Andes. The fjord is crossed by a numbe...
Article
Full-text available
The aim of this study was to determine the size distribution and flux of the mineral fraction collected in marine sediment traps in Mejillones Bay (23 degrees S) using image-based size analysis. In this bay the material settling in the water column is a mixture of biogenic particles and lithic grains. The sediments analyzed correspond to four sampl...
Article
Full-text available
The giant nitrate deposits of the hyperarid Atacama Desert (Chile) are one of the most extraordinary, yet enigmatic, mineral occurrences on Earth. These deposits are complex assemblages of highly soluble nitrates, chlorides, sulfates, perchlorates, iodates, and chromates, and their preservation is the result of prevalent hyperarid climate condition...
Conference Paper
Full-text available
Lithic particles in marine laminated sediments have been widely used for the interpretation and reconstruction of several continental processes. In the Mejillones Bay (23ºS), the marine laminated sediments constitute a high-resolution record at interannual-to-centennial time scales of the paleoceanographic variability in the subtropical Southeast P...
Article
The crustal-scale west-vergent San Ramón thrust fault system at the foot of the main Andean Cordillera in central Chile is a geologically active structure with Quaternary manifestations of complex surface rupture along fault segments in the eastern bor- der of Santiago city. From the comparison of geophysical and geological observations, we assesse...
Chapter
Full-text available
On 21 April 2007 (Mw 6.2) an earthquake triggered more than 500 landslides near the epicenter along the Aysén fjord, Chile. One of the major failures occurred at the Punta Cola Valley involving a volume of 20.9 million cubic meters of rock. The main rockslide was followed by a rock/debris avalanche involving talus and glacio-fluvial deposits in the...
Article
Full-text available
The San Ramón Fault is an active west-vergent thrust fault system located along the eastern border of the city of Santiago, at the foot of the main Andes Cordillera. This is a kilometric crustal-scale structure recently recognized that represents a potential source for geological hazards. In this work, we provide new seismological evidences and str...
Article
Full-text available
On 21 April 2007, an Mw 6.2 earthquake produced an unforeseen chain of events in the Aysén fjord (Chilean Patagonia, 45.5°S). The earthquake triggered hundreds of subaerial landslides along the fjord flanks. Some of the landslides eventually involved a subaqueous component that, in turn, generated a series of displacement waves—tsunami-like waves p...
Article
Full-text available
Site GNL Quintero 1 (GNLQ1), located in Quintero Bay (32 degrees S, Central Chile) constitutes the first evidence of a drowned terrestrial site on the continental West Coast of South America covered by sea-level rise after the Last Glacial Maximum. The site currently lies 650 m offshore and 13 m underwater, covers an area of similar to 64 m(2) and...