Abstract

The intensity distribution of the Limón earthquake of April 22, 1991 (Mw 7.7) was obtain using macroseismic information compiled from direct observations, personal and telephonic interviews and data recovered from different information sources. The earthquake was felt in a large region of Central America. The average perception radius estimated is ~ 620 km. The minimum intensity with which the earthquake was felt in Costa Rica was intensity IV at was determined in the northwestern part of the country. From this region the intensities increased until the mezoseismic region, located along the Caribbean side of the country, where the estimated intensities were between VIII and X degrees. In the mezoseismic zone occurred considerable landslides along the Caribbean spurs of the Talamanca Cordillera, sandy soil liquefaction in recent deposits located principally along the Caribbean coast and important damage over diverse civil works, standing out the damage to roads and bridges.

Keywords: Modified Mercalli Intensity; Macroseismic Information; Mezoseismic Zone; Geology of Costa Rica; Rupture Area