The first was at 4:23 a.m. about 12 kilometers (about 7.5 miles) south southwest of Santa María de Dota or 10 kilometers (6 miles) southeast of San Carlos de Tarrazú. The magnitude was estimated by the Laboratorio de Ingenieria Sismica at 3.7. Just 30 seconds later a second quake, this one estimated at 3.5 magnitude, took place at the same spot.
Then at 5:40 p.m. a 2.8 quake took place on the west shore of the Nicoya peninsula, according to the Observatorio Vulcanológico y Sismológico at Universidad Nacional.
At 9:35 p.m. a 3.2 quake took place in the middle of the gulf of Nicoya. The location was about 18.8 kilometers (about 12 miles) southeast of Paquera, said the Laboratorio de Ingenieria Sismica.