The peninsula of Nicoya moves 11 milimeters a year, going northwest, according to a test made by the National Seismologic Net of Costa Rica (RSN) and the Universities of Costa Rica and Indiana, Pennsylvania, US.
According to the test, called 'The Volcanic Arch of the Costa Rican Northwest', the movement of the techtonic plaque of the peninsula of Nicoya might be produced by the land lifting provoked by another plaque, named Cocos.
This causes compression, so the peninsulas of Nicoya and Santa Elena and the Volcanic Arch, laterally move out of the area where the lifting of Cocos pushes Costa Rica, said expert Walter Montero, from the Geological Sciences Investigation Center.
The analysis and investigation identified new techtonic falls, that were not included or known, close to Bijagua, Upala (province of Alajuela) or Tilaran ( province of Guanacaste).
'These quakes have the peculiarity of being of intermediate magnitude and very superficial, but they have caused local effects, 'said the geologist.
Nevertheless, official information brings two quakes in the same area, both of magnitude 6,5, the first one happened on October 10, 1911 and the second on April 13, 1973.
The investigation wants to offer equipments and knowledge to evaluate the geologic risks in the northwest of Costa Rica.