LOCALIZACIÓN DE HIPOCENTROS Y DETERMINACIÓN DE SU MAGNITUD EN TIERRA DEL FUEGO Y ZONAS ALEDAÑAS
LOCALIZACIÓN DE HIPOCENTROS Y DETERMINACIÓN DE SU MAGNITUD EN TIERRA DEL FUEGO Y ZONAS ALEDAÑAS
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火地岛和阿莱达地区的中心定位和震级确定
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
J. L. Ormaechea
中科院分区：
文献类型：
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作者：
Carolina Buffoni;N. C. Sabbione;Gerardo Connon;J. L. Ormaechea
为了研究火地岛的地震活动性，计算了中低震级地震的新震源位置。该地区有一个复杂的构造环境：该岛被一个名为Magallanes-Fagnano的转换断层穿过，该断层将火地岛分为两个大陆块。这个断层系统构成了南美洲-斯科舍板块边界的主要大陆段。该岛有着重要的地震历史，其中包括1949年12月发生的7.8级地震。1929年、1930年、1944年、1949年和1970年发生的地震报告是通过对历史地震活动性的研究而得知的。本文进行了震源定位和误差分析。2007年1月至12月期间，对五个地震台站的记录进行了分析。已经确定了180多个事件，其中一些与NEIC（国家地震信息中心）和ISC（国际地震中心）的事件进行了比较。用初至振幅计算了震级。大多数地震的震级在2到4度之间。关于震源深度，超过50%的定位地震的深度在前10公里。获得的地震活动图显示，除了与Magallanes-Fagnano断层有关的相当分散的地震活动之外，在达尔文科迪勒拉地区和斯科舍板块周围发现了集中的震中，显示了与研究的大地构造区域相关的证据。
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.