Since December 28, 1,800 tremors have been detected in the local region of Puerto Rico and the Virgin Islands and, of these, 717 have been located in the southern regions of Puerto Rico and South of Puerto Rico, reported Friday Seismic network.
The local region includes Puerto Rico, the North American and British Virgin Islands, and the east of the Dominican Republic, so that amount of 1,800 is limited to events in all faults around the island recorded by the Seismic Network, including the seismic sequence by the earthquake of magnitude 6.0 of last September 23 in the region of the Mona Canyon and the normal seismic activity of the North Falla area, north of the island.
Dr. Elizabeth Vanacore, of the Seismic Network, explained that, of the 717 earthquakes located in the regions south of the island, 622 are associated with the seismic swarm that began on December 28.
The first tremor felt on December 28, at 6:35 p.m. It was one of magnitude 4.7 and was located 7.76 kilometers southeast of Guánica, with a maximum intensity of V in Ponce. This earthquake was followed by one of magnitude 5.0 at 9:06 p.m., located 12.79 kilometers south-southeast of Guánica. In no case was a tsunami warning or warning issued.
Vanacore indicated that the earthquakes have a general behavior that has been studied by seismologists. These are divided, mainly, in the main event, such as 5.0 on December 28 and the aftershocks, such as minor tremors that continued.
“In general, the frequency of these aftershocks decreases over time. This means that, on the first day of the main event, we will have 10 times more earthquakes than on day 10. So we should see a decrease in the frequency of seismic activity over time. ”detailed.
However, he stressed that this behavior refers to frequency and not the magnitude of the events. “So there can still be (earthquakes) of significant magnitude in these aftershocks and with events such as last night 4.7, the system will be temporarily re-energized,” he said.
He also noted that “the public can expect to feel more events in the near future”, since the earthquakes are being registered near land and at shallow depth (less than 10 kilometers). This behavior also allows earthquakes to be registered by the Seismic Network with greater precision.
Of the total tremors of this seismic sequence, 29 have been reported as senses and 14 tremors have had magnitudes less than or equal to 3.5.
The last tremor felt in the sequence (reported by the citizens to the Seismic Network) was today, Friday, at 12:52 p.m. The quake of magnitude 3.6 was located 15.68 kilometers southeast of Guánica, had a depth of 3 kilometers and a maximum intensity of IV in Guayanilla.
The researcher indicated that the experts of the Seismic Network work to determine more accurately the area where each of these earthquakes originated, in order to know if they occurred in known failures or if they come from areas still unidentified. He also urged citizens to report any tremor.