Underlying mechanism of precursory activity from analysis of upward earthquake migration

作者：Molchanov O A^*

来源：Natural Hazards and Earth System Sciences, 2011, 11(1): 135-143.

DOI：10.5194/nhess-11-135-2011

In this paper we analyse the upward earthquake hypocentral migration in the ten known subduction zones and discuss a possible mechanism of such migration. The total time of the migration appears to range from 2.5 to 10 years. It leads to the estimation of the average velocity V(z) similar to 60 - 300 km yr(-1). It probably corresponds to the movement of the forcing agent like stress or deformation wave from depths of the upper mantle (600-700km) to the level of the lithosphere with subsequent initiation of fluid migration inside the crust to trigger shallow earthquakes. Averaged over all zones upward migration travel time is about 5 years (< V(z) >approximate to 120 km yr(-1)) that coincides approximately with the period of characteristic temperature variation (El Nino) and crustal seismic periodicity in the Pacific region. These findings are helpful for the study of the seismic precursors and analysis of earthquake triggering.

• 出版日期2011