Localización de hipocentros y determinación de su magnitud en Tierra del Fuego y zonas aledañas
Keywords:
Tierra del Fuego, Magallanes-Fagnano transform system, earthquake locations, magnitude mb, seismicityAbstract
New hypocentre locations of earthquakes with low to medium magnitude have been calculated in order to study Tierra del Fuego seismicity. The region has a complex tectonic setting: the island is crossed by a transforming fault named Magallanes-Fagnano which divides Tierra del Fuego in two continental blocks. This fault system constitutes the major continental segment of the South America-Scotia plate’s border. The island has an important seismological history which includes an event of magnitude 7.8 occurred on December 1949.
Reports of earthquakes occurred in 1929, 1930, 1944, 1949 and 1970 are known by a study of historical seismicity. In this paper hypocentre locations and error analysis have been carried out. Records at five seismological stations have been analyzed during January-December 2007. More than 180 events have been
identified and some of them were compared to events of NEIC (National Earthquake Information Center) and ISC (International Seismological Centre). Magnitude determinations have been calculated with first arrival amplitude. The majority of earthquakes have magnitude mb between 2 and 4 degrees. With respect to hypocentral depths, more than 50% of located earthquakes have their depths in the first 10 km. The seismicity map obtained shows that beyond rather dispersed seismicity related to the Magallanes-Fagnano fault, a concentration of epicentres is found in the Darwin Cordillera area and in the Scotia plate surrounding, displaying evidence of a correlation with the geotectonic area of study
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References
Adaros Cárcamo R. E. 2003. Sismicidad y Tectónica del extremo sur de Chile. Tesis Magíster, Universidad de Chile: 82p.
Barker P.F., J. Burrell, 1977. The opening of the Drake Passage. Marine Geology 25: 15-34.
Dalziel I.W.D., 1989. Tectonic of the Scotia Arc, Antartica. Field Trip Guidebook T180, 206pp.
De Wit M. J. 1977. The evolution of the Scotia Arc as a key of the reconstruction of southern Gondwanaland. Tectonophysics 37 (1-39): 53-82.
Del Cogliano D., R. Perdomo y J. Hormaechea, 2000. Desplazamiento entre placas tectónicas en Tierra del Fuego. Actas de la XX Reunión Científica de la AAGG, Mendoza (En CD).
Febrer, J., M. Plascencia y N. Sabbione 2000. Local and Regional Seismicity from Ushuaia Broadband Station Observations (Tierra del Fuego). Terra Antartica. Vol 8 (2), 35-40.
Fuenzalida R.H., 1972. Geological Correlation Between the Patagonian Andes and the Antartic Peninsula and Some Tectonic Implications. Master Thesis, Standford University, 75p.
Grunow A., D. V. Kent y I. W. D. Dalziel, 1991. New paleomagnetic data from Thurston Island: implications fot the tectonics of West Antartica and Weddell Sea opening. J. Geophys. Res. 96, 17935-17954.
Grunow A.W., I.W.D Dalziel, T. M. Harrison y M. T. Heizleir, 1992. Structural geology and geochronology of subduction complexes along the margin of Gondwanaland: new data from the Antartic Peninsula and southmost Andes. Geol. So. Am. Bull. 104, 1497-1514.
Havskov, J. and L. Ottemöller, 2008. SEISAN: The Earthquake Analysis Software, Institute of Solid Earth Physics, Bergen University, Norway. Version 8.2.1. (http://www.ifjf.uib.no).
Lienert, B.R.E y J. Havskov, 1995. A computer program for locating earthquakes both locally and globally, Seismological Research Letters, 66, 26-36.
Mendoza, L., R. Perdomo, J. L. Hormaechea, D. Del Cogliano, R. Dietrich, M. Fritsche y A. Richter, 2007. Determination of recent horizontal crustal displacements at the South America/Scotia tectonic plate boundary in Tierra del Fuego by GPS, GEOSUR (Poster).
Plascencia, M., G. Connon, J.L. Hormaechea y N. Sabbione, 2002. Determinación preliminar de epicentros registrados en la estación sismológica Despedida (DSPA). Provincia de Tierra del Fuego. Actas de la XXI Reunión Científica de la Asociación Argentina de Geofísicos y Geodestas. En CD, pp., 285-289.
Sabbione N., G. Connon, J.L. Hormaechea y M. L. Rosa, 2007. Estudio de Sismicidad en la Provincia de Tierra del Fuego. Geoacta. Vol.32: 41-50
Smalley, R. Jr., Kendrick, Bevis, Dalziel, Taylor, Lauría, Barriga, Cassasa, Olivero and Piana, 2003. Geodetic determination of the relative plate motion and crustal deformation across the Scotia-South plate boundary in eastern Tierra del Fuego. Geoch. Geoph. Geos, Elect Jour AGU, Vol 4, Nº9.
Veith, K. F. and G. E. Clawson, 1972. Magnitude from short period P-wave data. Bull. Seism. Soc. Am. 62, 435-440.
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