At 3:34AM Thursday 21st February 2019, a Magnitude 4.2 earthquake occurred at 33.2 KM N of Macuro, Venezuela and 62.0 KM NW of Port of Spain, Trinidad and Tobago. This event occurred at a shallow depth of 18.5 KM. It was not reported felt across Trinidad.
Based on the location of this earthquake, it likely occurred in seismic zone 1. Within zone one, two main mechanisms drive seismic activity.
Firstly, the South American plate is beginning to rapidly descend into the Earth’s mantle as the detached oceanic lithosphere exists at depths between 50 to 300 kilometers. (Russo et al. 1993). This zone is one of the most active seismogenic sources in the Eastern Caribbean and has the potential to generate earthquakes up to Magnitude 8.0.
Secondly, at shallower levels, such as where this earthquake occurred, the North Coast Fault Zone, as well as the El Pilar Fault, part of the Boconó-San Sebastian-El Pilar Fault system, runs across Zone 1. These fault systems compensate for the stress built up as the Caribbean plate slides past the South American plate. Hence, most of these earthquakes from these fault systems are between 0 to 50 kilometers.
This area has some of the highest seismicity in the Eastern Caribbean, and this location accounts for the greatest number of earthquakes in the Trinidad and Tobago region. Strong earthquakes in this area have occurred in the past, with the largest being over magnitude 7.0.
Earthquakes *cannot* be predicted – meaning the precise time, date, magnitude, depth etc. cannot be known ahead of time based on current research and technology.
Generally, in Trinidad and Tobago, a seismically active area, earthquakes of this magnitude, up to M8.0 and greater, are possible in area, and this statement has been repeated by seismologists at the U.W.I. Seismic Research Centre for decades.
Each year, over 2,200 seismic events are recorded in the Eastern Caribbean. On average, the Eastern Caribbean has seen a pattern of major (M7.0-M7.9) quakes every 20 to 30 years. That pattern has stayed true. The last major (M7.0-7.9) quake occurred north of Martinique in 2007.
Historical patterns indicate great earthquakes (M8.0+) on the Richter Scale have occurred every century or so in the region. The probability of another event at that level is high since the last >M8.0 earthquake occurred in 1843.
Now is the time to create or go over your earthquake preparedness plan and know what to do during, before and after an earthquake. See here for more details.
This event has been reviewed by the Venezuelan Foundation for Seismological Research and is considered final.