At 6:53 PM on Thursday 25th July 2019, a preliminary Magnitude 3.4 (Md or Mt) earthquake occurred 33 KM N of Arima, Trinidad and Tobago and 43 KM NE of Port of Spain, Trinidad and Tobago
This event occurred at a shallow depth of 19 Kilometers. This information (above) is preliminary from the U.W.I. Seismic Research Centre, the authority for seismic and volcanological information in the Eastern Caribbean. Quake parameters such as location, depth and magnitude may change upon review from a seismologist at the SRC.
This event was reported felt, with weak shaking, across parts of the Northern half of Trinidad. You can submit your felt reports to the U.W.I. Seismic Research Center.
Note that across the globe, different seismic monitoring agencies use different methods, or several methods, for processing quake parameters. Each method has its limitations and will likely produce different results within the ranges of the uncertainty of that data. This is generally accepted within the scientific community.
Based on the location and depth of this earthquake, it is tectonic in origin and occurred within seismic zone 4, north of Trinidad.
Earthquakes in Zone 4 can be associated with the subducting slab of the South American Plate, resulting in a deeper event of depths between 40-55 KM, but it can be deeper. Quakes in this area can also be associated with the North Coast Fault System, which runs just offshore the Northern Coast of Trinidad, where events are usually less than 40 KM depth, where this quake occurred. This area typically produces light (M4.0-4.9) or moderate (M5.0-5.9) magnitude earthquakes. Seismic events in this zone tend to produce fewer aftershocks than earthquakes elsewhere across Trinidad and Tobago.
Within 10 kilometers of the epicenter of the main earthquake, since 1960, quakes have generally registered below magnitude 4.7. This quake occurred on March 2nd, 1967. The most recent quake in this location occurred on January 4th, 2019 at a magnitude 3.9.
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, across the Eastern Caribbean, a seismically active area, earthquakes of this magnitude, up to M8.0 and greater, are possible 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.