Seismotectonics of the Nicaraguan Depression from Recent Seismicity

Abstract

After 9 years without significant earthquakes’ occurrence in the Nicaraguan Depression, in the period 2014-2016 have occurred 2 events with magnitude bigger than 6 and several with magnitude bigger than 5 together with a lot of less magnitude events. In this work an analysis of spatial-temporal behaviour of every cluster has been provided, including epicentres’ relocation and time history analysis of slip in the focus for earthquake of April 10th, 2014. Additionally there have been determined the moment tensors of bigger earthquakes inside every cluster. The earthquakes held toward the centre of the depression align along NE-SW trending faults and show predominantly left lateral strike-slip movement, while the ones in the inner border align N-S and show a normal mechanism behaviour. Based in obtained results, summing the data of moment tensors of past earthquakes from global databases, and with the consideration of other evidences about geology and tectonics of the study area, it is provided a seismotectonic interpretation of those results as a proposal of a seismotectonic model for Nicaraguan Depression. The proposal includes Mmax estimations and criteria about the more probable foci of future middle size earthquakes in the Nicaraguan Depression. Seismotectonics of the Nicaraguan Depression from Recent Seismicity