Abstract
This study shows the rapid calculation of the Local Magnitude of thc Earthquake of Limón, based on accelerograms from the Strong Ground Motion Measurement Program ofthe Seismic Engineering, Laboratory of the University of Costa Rica.
The Local Magnitud is a measure of the size of an earthquake, determined for short periods and at rather close distances. This parameter is one of interest for the seismic-resistand engineering, and it is also used in seismic zoning studies.
The Local Magnitude of the Seism of Limón, measured from the acelerographics records, is 7.24 +/- 0.20 standar deviation units.
The attenuation ratio of this earthquake shows peak horizontal acceleration values out of the acceptable range, as is the case of the stations of Cartago, Carlos Monge Library (University of Costa Rica), Alajuela and San Ramón. This behaviour is possibly due to the stations being located on soft soils, which causes an amplification effect on seismic waves.