Wednesday, April 6th 2011- According to a public statement issued at 8:49pm last evening by the Puerto Rico Seismic Network (PRSN), 36 minor and micro earthquakes associated with a seismic swarm in the Latitude 19o North Fault Zone have been recorded between the period 4th to 5th April, 2011.
The term seismic swarm is applied when a sequence of seismic events, with similar characteristics occurs in the same region, during a short period of the time and within a few hours or days.
PRSN has reported that from April 4th at 8:00 pm until April 5th at 8:21 am a total of 107 seismic events, during a period of 12.5 hours, were identified in the Latitude 19o North Fault Zone 71.87 km North of the coast of Manati, Puerto Rico. Approximately 71 of those seismic events have been classified as “undetermined” due to the lack of sufficient information to process them as they were registered by less than 3 seismic stations. This seismic swarm was generated specifically between Latitudes 18.994oN – 19.197o N and Longitudes 66.527o W – 66.459o W. The seismic events ranged in magnitudes between 2.2 to 3.46 and depths from 5.9 km to 33.7km. Eight (8) earthquakes had magnitudes greater than 3.0 during the period of the swarm. Two events were reported as felt in Puerto Rico.
The Puerto Rico Seismic Network is responsible for processing seismic activity data for the Puerto Rico and Virgin Islands Region. So far for the month of April, 51 earthquakes have been located in this region. PRSN indicates that this level of seismic activity is considered normal based on the active movement in the subduction zone in this part of the region.
The DDM takes this time to continuously remind the BVI community that we are vulnerable to earthquakes. During an earthquake it is important to stay calm, if you are inside stay there, move away from ceiling fans, glass windows and doors or anything that may fall. Get under a desk or sturdy piece of furniture cover your head and hold on. If outdoors, move into an open area away from trees, building, or utility wires and poles. During an earthquake the more you move the more likely you are to be hurt, so refrain from entering or exiting a building at the time of the impact.Persons can contact the DDM at 468-4200 for further information on any earthquakes that may have been felt.