Residents in the vicinity of Bijagua in the canton of Upala have experienced more than 100 earthquakes since three strong ones took place within 18 minutes Saturday night. The first at 7:58 p.m. was estimated at 5.4 magnitude. Five minutes later a magnitude-4 quake took place. Then at 8:16 p.m., a quake estimated at 5.1 magnitude took place.
The Red Sismológica Nacional listed aftershocks ranging from 2.5 to 4.5 overnight and into Sunday.
Four homes were reported to be so heavily damaged that they will have to be destroyed. The magnitudes of even the strongest quake was not unusual. But the impact was not typical.
Products were thrown off grocery shelves, sidewalks were ruptured, and homes ended up with cracked walls.
Water was off in the area until Sunday afternoon, and there were power outages.
As earthquake researchers have said in the past, it is the consistency of the ground that can amplify the effect of a quake.
Residents alerted the Red Sismológica Nacional to a river that had become discolored in Armenias de Upala. The national emergency commission plans an overflight today to assess the damages in a rural area. Rivers sometimes turn color because of a major slide upstream.
The epicenters were not far from the Nicaraguan line in northern Costa Rica.