The Samara (Costa Rica) earthquake of 5 september 2012 (Mw 7.6)

Abstract

On 5 September 2012 a magnitude Mw 7.6 earthquake struck the Nicoya Peninsula in Costa Rica. Based on two methods and using 1D and 3D velocity models, we present three earthquake location solutions, which nearly converge at the epicenter. The size, location, and the focal mechanism reported by different seismological institutions show that this earthquake was generated at the Cocos-Caribbean plate interface. An intensity map is also presented based on the intensities of 190 localities in Costa Rica for the main shock and 77 localities for the largest aftershock. The highest intensity for the main shock was VII (Modified Mercalli) at the epicentral area and in the Grecia, Sarchi, and Naranjo region. The earthquake distribution during the first month after the earthquake defines an aftershock area of about 100x40 km²