THE APRIL 6, 2009 EARTHQUAKE AT L’AQUILA: A PRELIMINARY SEISMO-MAGNETIC ANALYSIS OF MULTIPOINT GROUND-BASED MAGNETIC FIELD MEASUREMENTS

Preceded by a persistent seismic activity, an earthquake (Ml=5.8, Mw=6.3) hit L’Aquila (Italy, LT=UT+1) on April 6, 2009, 01:32 UT, causing more than 300 deaths (including 47 students of the local university) and a tremendous devastation of the town and its territory. We present a preliminary seismo-magnetic analysis of local ULF measurements (station AQ) preceding the earthquake, focusing attention on the possible occurrence of features similar to those identified in previous seismic events (Hayakawa et al., Geophys. Res. Lett., 23, 241, 1996.; Molchanov et al., Geophys. Res. Lett., 19, 1495, 1992.; Prattes et al., NHESS, 2008). Located ~6 km from the epicentre of the most intense event, instrumentation consists of fluxgate and induction magnetometers with a sampling frequency of 1 Hz. The station is part of the South European GeoMagnetic Array (SEGMA) with stations in Italy, Hungary and Bulgaria. Simultaneous observations from all SEGMA stations were used to discriminate between global and local aspects and to identify the possible occurrence of signals of lithospheric origin. A brief analysis of the seismo-electromagnetic environment in the earthquake region based on subionospheric VLF radio paths in Europe is presented too. (A. Rozhnoi et al., NHESS, 2009).