Abstract
Using strike and dip of maps of the Compañía Petrolera de Costa Rica, the palco-stresses of the Limón Basin are determined. They are compared to 1991 stresses calculated from fractures occurred during the Limón 1991 earthquake.
The stresses have not change from Paleocene to Quaternary. They are trending between N0 E-N40 E, with a greater tendency toward the north-south in the north and northeast (N20 E-N40 E) region than in the central and southern region. A tectonic event occurred in the Eocene-Oligocene which had the same orientation.
The stresses calculated in the faulting zones related to the Limón earthquake very similar, except in the central region where it seems to be dominated by a northeast tension. The mapped faulting zones are the borders of blocks which moved during the earthquake. The similarity between the coseismic faults and the high-angle faults of the Limon Basin, show that they were older faults which were reactived during the earthquake.