Strong earthquakes and geomagnetic jerks: a cause-effect relationship?

Abstract

Secular variation of the geomagnetic field observed at the Earth's surface has been found to undergo impulsive accelerations Gerks) lasting less than a few years. In this paper the relations between jerks and the occurrence of strong earthquakes (Ms ≥ 7.0) is analysed for this century , disclosing a positive correlation between the maximum number of recorded strong earthquakes and jerk occurrence. Analysing only very strong earth- quakes (Ms ≥ ; 8.0) the jerks seem to take pIace with a time delay of about 2-5 years with respect to earthquake occurrence. Reliable processes that could justify this intriguing correspondence are suggested.