Geomagnetic Disturbances and Seismic Events in the Vrancea Zone from in Situ Data

摘要

Based on example from the Vrancea's concentrated seismicity zone the connection between definite type of geomagnetic disturbances and 200 earthquakes during the period of 1988-1996 is shown. The energy classes of earthquakes are related to abrupt changes ("gradients") in H-component of geomagnetic field. Taking into account the temporal interval from maximum of sub-storm up to the shock, the relationship between geomagnetic disturbances and earthquakes is always positive. The time interval between maximum of polar sub-storm and earthquake is correlated with the depth of the earthquake. Differences in the duration of polar substorms before crustal (shallow) and deep earthquakes are revealed. Four main types of morphological features of geomagnetic variations preceding the seismic event are established.