Seismicity along the Magallanes-Fagnano fault system
Author
dc.contributor.author
Ammirati, Jean-Baptiste
Author
dc.contributor.author
Flores, M. Constanza
Author
dc.contributor.author
Ruiz Tapia, Sergio
Admission date
dc.date.accessioned
2021-01-18T21:46:35Z
Available date
dc.date.available
2021-01-18T21:46:35Z
Publication date
dc.date.issued
2020
Cita de ítem
dc.identifier.citation
Journal of South American Earth Sciences 103 (2020) 102799
es_ES
Identifier
dc.identifier.other
10.1016/j.jsames.2020.102799
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/178268
Abstract
dc.description.abstract
The Magallanes-Fagnano fault (at similar to 51-56 degrees S) is a continental NW-SE transform fault zone that marks the boundary between the South American Plate (north) and the Scotia Plate (South). In 1949, two crustal seismic events of estimated magnitude M > 7 were located in this area using teleseismic records. Although, this region is scarcely populated, such shallow seismicity could represent a considerable threat to the remote urban centers in this sector. The characterization of the local seismicity always lacked good quality records and permanent instrumentation. In the recent past years, permanent seismic stations (CSN and INPRES-CTBTO) were deployed in the Tierra del Fuego Island and Southern Patagonia, providing with continuous time, broadband records of waveform data. In order to obtain better insights about the local seismicity associated with the Magallanes-Fagnano fault, we jointly inverted teleseismic receiver functions with Rayleigh-wave dispersion data to build a calibrated velocity model for the study region. In parallel, we analyzed the continuous waveforms to automatically detect local earthquakes and locate them using our regional velocity model. Our results show: 1) Shallow seismic events distributed along the Magallanes-Fagnano fault. 2) Diffuse seismicity characterizing the South American crust, north of 53 degrees S. Our observations suggest two mechanisms of crustal deformation. In the Tierra del Fuego Island the seismicity is mostly associated with the Magallanes-Fagnano fault system. In the Southern Patagonia, along the Patagonian Andes the seismicity would be mostly due to isostatic rebound following the retreat of the Patagonian Ice sheet.
es_ES
Patrocinador
dc.description.sponsorship
Universidad de Chile through the Programa Riesgo Sfsmico - Actividades de Interes Nacional (AIN)
Agencia Nacional de Investigacion y Desarollo of Chile (ANID) through the Fondo de desarollo Cientffico y tecnico program (FONDECYT)
3200633