Earthquake potential in Costa Rica using three scenarios for the central Costa Rica deformed belt as western boundary of the Panama microplate

Abstract

The Central Costa Rica Deformed Belt (CCRDB) is a diffuse faulting area that represents the western border of the Panama Microplate. Using the Markov Chain – Monte Carlo method and under three scenarios of the spatial distribution of the CCRDB, we analyzed the inter-seismic crustal deformation in Costa Rica and its surroundings based on the results of the Global Navigation Satellite System (GNSS) observations for Costa Rica, Nicaragua, and Panama. We assumed that the observed inter-seismic crustal deformation on the surface is a result of the kinematic effects of the rigid tectonic blocks motion, the elastic deformation due to the block interface interactions and the internal strain inside of the tectonic blocks. Assuming that the seismic moment in the subduction and inland interfaces is accumulated only as an elastic strain and is then released co-seismically, the resulting seismic moment accumulated rates reflect the capacity for producing earthquakes Mw > 8 along the Cocos Plate convergence and earthquakes Mw > 7 along the inland interfaces. Although these are the values that the modeling outputs, limited historical data suggests that this earthquake potential might be overestimated, but the historical seismicity in Costa Rica is still short for disesteeming higher earthquake potential levels.