Patricia Pedraza

• seismologist at Servicio Geológico Colombiano

El Servicio Geológico Colombiano presenta los tensores de momento sísmico y mecanismos focales calculados para sismos localizados en el territorio nacional y regiones fronterizas desde 2014 hasta 2021. Estas soluciones se obtuvieron usando diferentes métodos basados en inversión de formas de onda (SWIFT, SCMTV, Fase W e ISOLA) y polaridades de prim...

The boundary between the Northern Andean block and the South American plate is a first‐order tectonic structure in Colombia with historically M > 7 earthquakes. However, details about individual sections of the system remain unknown. We illuminate the seismotectonic of the Algeciras fault by investigating an earthquake sequence that started on 24 D...

The recycling of water into the Earth’s mantle via hydrated oceanic lithosphere is believed to have an important role in subduction zone seismicity at intermediate depths. Hydration of oceanic lithosphere has been shown to drive double planes of intermediate-depth, Wadati-Benioff zone seismicity at subduction zones. However, observations from trenc...

A large earthquake (Mw 7.7) occurred on 16 April 2016 within the source region of the 1906 earthquake in the Ecuador-Colombia subduction zone. The 1906 event has been interpreted as a megathrust earthquake (Mw 8.8) that ruptured the source regions of smaller earthquakes in 1942, 1958, and 1979 in this subduction. Our seismic analysis indicated that...

Bogotá, a megacity with almost 8 million inhabitants is prone to a significant earthquake hazard due to nearby active faults as well as subduction megathrust earthquakes. The city has been severely affected by many historical earthquakes in the last 500 years, reaching MM intensities of 8 or more in Bogotá. The city is also located at a large lacus...

Abstract: We studied the earthquake source parameters of the Mw 5.9 earthquake which struck the center of Colombia on May 24, 2008. We used seismic waveforms and geodetic measurements (InSAR) to determine the location, focal mechanism, and coseismic surface displacements. We determined the focal mechanism of the main event using teleseismic P wave...

We use seismic waves for a magnitude 6.3 intermediate-depth (160 km) earthquake in the Bucaramanga Nest, Colombia, to infer a complex rupture process with two distinct stages, characterized by different rupture velocities possibly controlled by the evolution of strength on the fault. Our integrated data processing permitted to precisely characteriz...

The Servita fault is a thrust located in the center of Colombia and whose main scarp is at 5 km west of Villavicencio (500.000 inhabitants). According to geophysics data as gravity, magnetic, and seismic, this fault was confirmed how a large cortical structure in the Colombian Eastern Cordillera. The Servita fault possibly was originated like a sut...

On May 24th, 2008, 19:20 UTC a 5.7 earthquake struck the center of Colombia. The Geological Survey of Colombia (SGC) put the earthquake epicenter in the SE of the capital Bogotá at a depth less than 30km. The earthquake affected 5 municipalities in the department of Cundinamarca: Quetame, Fosca, Guayabetal, Fómeque, Bogotá and El Calvario in Meta....

[1] Intermediate-depth earthquakes occur at depths where temperatures and pressures exceed those at which brittle failure is expected. There are two leading candidates for the physical mechanism behind these earthquakes: dehydration embrittlement and self-localizing thermal shear runaway. A complete energy budget for a range of earthquake sizes can...

Field data, aerial photography, and satellite imaging have allowed the identification of active tectonic features in Servita fault which is a thrust whose scarp is located 5km west of Villavicencio in the center of Colombia. This fault is thrusting Devonian rocks over Early Cretaceous rocks. This is one of the main faults of the Eastern Frontal Fau...

A geometric model for the subduction of the Nazca plate beneath the South American plate in southwestern of Colombia is proposed based on the relocation of hypocenters of local and distant earthquakes. By means of the simultaneous inversion of teleseismic P and SH body waves, the depths of the 15 events with Mw ≥ 5.8 were constrained, and the hypoc...