Article ID Journal Published Year Pages File Type
4693806 Tectonophysics 2009 7 Pages PDF
Abstract

One major tectonic feature in the southern part of Spain is the Crevillente Fault Zone (CFZ) which can be traced over 600 km. A short-term microseismic feasibility study was carried out in the area around Coy to investigate the seismic activity of the CFZ by mapping the local seismicity distribution. The area under investigation is of high interest because three moderate earthquakes have occurred nearby since 1999. The measurements were performed with two small arrays, whereas one array was relocated every day to increase the spatial resolution. In the measurement period of 14 nights, including 4 daytime records, 189 events in the magnitude range − 1.8 ≤ ML ≤ 1.3 were detected, of them 133 events could also be located. According to the bulletin of the Instituto Geográfico Nacional, the local network recorded 1 event in the area under investigation in the same period. The results of this short-term measurement show an increased detectability by using small arrays for event recording and prove that there is a high rate of microseismicity below the detection threshold of the local network. For event location, the regional velocity model had to be adapted to our small scale, short epicentral distance application by reducing vP to 4 km/s using a homogenous half space model. The distribution of the events does not indicate a seismic activity along the CFZ. It is rather concentrated to the south around the epicentral zone of the La Paca earthquake that occurred 114 days before our measurement campaign. Some events show a high waveform similarity. They can be attributed to the same fault segment.

Related Topics
Physical Sciences and Engineering Earth and Planetary Sciences Earth-Surface Processes
Authors
, ,