Costa Rica M7.6 ( Sep. 5, 2012)
Fig.1: Data from USGS and UTC was used. Epicenter distribution from 1964 to this event (14:42). The red cross shows the epicenter.
Fig.2 ; Epicenter distribution of M>=6.5 . This event occurred near 1978 M7.2 event. Recently, M7.4 occurred about 300km distance from the epicenter on Aug. 27.
Fig.3 : Tiem-space distribution of events occurred in the area in fig.2. This figure shows the source region was a seismic gap.
Fig.4 : Epicenter distribution which generated the causarity using Utsu catalog. About 10,000 people were killed by the event on 1972 Dec.23 and 26 people were kill by the event on 1973 April 14.
Fig.5 : Plate distribution map ( after USGS homepage).