(QCOSTARICA) The seismic behavior that has been studied for years in Costa Rica’s central Pacific, where the 6.2 magnitude earthquake (upgraded from 6.0) occurred on August 24 at 3:51 pm, reveals that there is a high probability that a similar earthquake will occur soon.
According to Marino Protti, of the Volcanological and Seismological Observatory of Costa Rica (Ovsicori), it is what they call duplets or seismic pairs.
“In most cases, not always, they appear as seismic pairs, where an earthquake of magnitude close to 6 occurs and after a few hours, or a few days, even in a couple of weeks, another one appears as part of the sequence, of similar magnitude and in some cases even a little greater in magnitude,” said the seismologist and researcher a the National University of Costa Rica (UNA).
Lepolt Linkimer, of the National Seismological Network (RSN) agrees with him, stating that in the following week there is a 31% probability that an earthquake of magnitude greater or equal to 5 will occur.
Therefore, residents of the areas where it was felt the most should not be surprised if the tremor occurs.
Linkimer, however, put the chances that this tremor would be part of the pair, will exceed or equal in magnitude to that of this Monday, at only 4%.
In January of this year, a seismic duplex occurred in Dominical de Osa and was felt in the Central Valley.
Nor is it ruled out that this seismicity revitalizes other faults near or far.
This Monday’s earthquake is the second of magnitude equal to or greater than 6 located in the seismogenic zone near Jacó since 1973, when the RSN was founded.
According to about 1,000 reports received by the RSN, the earthquake was felt throughout the country and so far the highest aftershock has been 3.6.
There are dozens of microseisms less than two degrees in the area, but up to 2 pm Tuesday, August 25, the RSN has precisely located 19 aftershocks, six of them greater than magnitude 3.
Aftershocks greater than magnitude 3
- Aug 24, 3:55 pm, M 3.1
- Aug 24, 3:58 pm, M 3.3
- Aug 24, 5:05 pm, M 3.1
- Aug 24, 8:54 pm, M 3.6
- Aug 24, 9:44 pm, M 3.0
- Aug 25, 4:11 am, M 3.2
The central Pacific region is seismically one of the most active in the country.
Almost three years ago, on November 12, 2017, a magnitude 6.2 earthquake occurred about 18 km southeast of the one that occurred on Monday.
Similarly, near there, the Cobano earthquake, with a magnitude of 7, was on March 25, 1990, which activated the Puriscal seismic swarm months later, the largest in the country’s historical records.