Tectonomagnetic field observations in central Italy 1989–1995

Abstract

It has been reported that earthquakes and volcanic eruptions produce significant variations in the geomagnetic field. To investigate possible tectonomagnetic effects related to seismic activity, the Istituto Nazionale di Geofisica installed a seismomagnetic network in central Italy; the area was selected after a magnetic noise survey. Geomagnetic field intensity data are simultaneously recorded at four magnetometer stations and at L'Aquila Geomagnetic Observatory, which is located in the same area. The data are differentiated in order to detect local magnetic field anomalies. The present study reports geomagnetic field observations in central Italy from July 1989 to March 1995 and also discusses the detectability of a tectonomagnetic effect in this area. A variation of about 5 nT over a two-month period (January–February 1990) has been observed in the geomagnetic field. No other anomaly has been observed, although moderate seismicity occurred in central Italy during the study period.