ALVARADO , Alexandra

The recent development of a national seismic broadband network in Ecuador enables us to determine a comprehensive catalog of earthquake focal mechanisms at the country-scale. Using a waveform inversion technique accounting for the spatially variable seismic velocity structure across the country, we provide location, depth, focal mechanism and...

Temporary seismic networks installed in urban areas provide a powerful tool for investigating the shal-low geological structure and assess the seismic hazard using seismic interferometry. Quito, the capital of Ecuador, is located in a high seismic zone, placed at 200 km from the Pacific sub-duction zone and surrounded by crustal-faults prone to...

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The Andean margin is one of the most active subduction zone worldwide (e.g., the1960 Mw 9.5 Chile or the Mw 8.8 1906 Ecuador earthquakes). We here proposethat the interseismic coupling along the Andean megathrust relates to spatialvariations along the interface as well as the fore-arc geology and inherited faultzones. For such matter, we...

International audience

International audience

In 1906, an earthquake with a magnitude estimated between M w 8.4 and 8.8 occurred in the subduction zone along the coast of Ecuador and Colombia. This earthquake caused extensive damage on the coast but had a rather small impact on the capital city of Quito, situated 180 km away. At that time, the city of Quito extended over a small area with...

A new view of Ecuador's complex geodynamics has been developed in the course of modeling seismic source zones for probabilistic seismic hazard analysis. This study focuses on two aspects of the plates' interaction at a continental scale: (a) age‐related differences in rheology between Farallon and Nazca plates—marked by the Grijalva rifted...

International audience

Summary In 1906, an earthquake with a magnitude estimated between Mw 8.4 and 8.8 occurred in the subduction zone along the coast of Ecuador and Colombia. This earthquake caused extensive damage on the coast but had a rather small impact on the capital city of Quito, situated 180 km away. At that time, the city of Quito extended over a small...

SUMMARY In 1906, an earthquake with a magnitude estimated between Mw 8.4 and 8.8 occurred in the subduction zone along the coast of Ecuador and Colombia. This earthquake caused extensive damage on the coast but had a rather small impact on the capital city of Quito, situated 180 km away. At that time, the city of Quito extended over a small...

Quito, the capital city of Ecuador hosting ∼2 million inhabitants, lies on the hanging wall of a ∼60-km-long reverse fault offsetting the Inter-Andean Valley in the northern Andes. Such an active fault poses a significant risk, enhanced by the high density of population and overall poor building construction quality. Here, we constrain the...

International audience

The city of Quito (3M inhabitants), capital of Ecuador, is prone to seismic hazard and the associated risk is increasing due to its growing. The city has been damaged several times in the past by earthquakes that occurred on crustal faults around Quito or in the Cordillera (Beauval et al., 2010). As far as we know, the earthquakes that occurred...

Along the Ecuadorian margin, oblique subduction induces deformation of the overriding continental plate. For the last 15 Ma, both exhumation and tectonic history of Ecuador suggest that the northeastward motion of the North Andean Sliver (NAS) was accompanied by an eastward migration of its eastern boundary and successive progressively...

Based on new geological data and analysis of Digital Elevation Model, we update the active fault mapping and determine earthquake geology hints of a section of a major crustal active fault system of continental Ecuador, namely the Pallatanga Fault to its junction with the Cosanga Fault, a part of the continental-scale dextral shear zone between...

Along the Ecuadorian margin, the North Andean Sliver is moving in the northeastward direction due tothe oblique subduction of the Nazca plate. The opening of the gulf of Guayaquil is a consequence of thismotion. Two principal models compete to explain the opening. One proposes an opening achievedessentially with strike slip motion along a...

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The Billecocha plateau (4000 m a.s.l.) lies in the high elevation Ecuadorian Andes volcanic arc. It overhangs by 2000 m above the interandean valley. Both the plateau and surrounding volcanoes are heavily affected by active faulting characterized by straight, sharp and discontinuous scarps within a 6 km wide and 24 km long corridor. Contrasting...

The continuous Global Positioning System (cGPS) network operating in the northern Andes (Ecuador and Colombia) for about a decade has the main objectives of quantifying interseismic coupling along the subduction interface, detecting occurrence of transient aseismic episodic slip, detailing the rupture kinematics of large earthquakes, recording...

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Based on new geological data and the analysis of a 4 m spatial resolution Digital Elevation Model (DEM), we provide a detailed and comprehensive description of section of the Chingual Cosanga Pallatanga Puna Fault System, a major active fault system in Ecuador. This work allows estimating new slip rates and large earthquakes parameters...