On Saturday, two minor earthquakes were recorded east of Barbuda and northeast of Antigua, both of which were not reported felt.
According to the University of the West Indies Seismic Research Centre (UWI SRC), the first quake struck at 12:51 AM and was recorded at a minor magnitude of 3.5 (mt). Later in the night, at 10:18 PM, the UWI SRC recorded another minor magnitude 3.8 earthquake. Both quakes were located in similar locations, at a similar depth, between 34 and 39 kilometers.
The UWI SRC, the authority on seismic and volcanological information in the English-speaking Eastern Caribbean, has reviewed this information.
Shaking was not reported in Antigua and Barbuda. You can submit felt reports to the University of the West Indies Seismic Research Centre.
There is no tsunami threat.
There are four conditions necessary for an earthquake to cause a tsunami:
- The earthquake must occur beneath the ocean or cause material to slide within or into the ocean.
- The earthquake must be strong, with at least a magnitude of 6.5.
- The earthquake must rupture the Earth’s surface and occur at a shallow depth—less than 70 kilometers below the surface.
- The earthquake must cause vertical movement of the seafloor (up to several meters).
None of these conditions occurred.
Note that different seismic monitoring agencies use different methods, or several methods, for processing quake parameters worldwide. Each method has its limitations and will likely produce different results within the range of the data’s uncertainty. This is generally accepted within the scientific community.
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Earthquake Magnitude & Intensity
Can earthquakes be predicted or forecasted?
Based on historical and instrumental records, over 800 events have occurred within 20 kilometers of Saturday’s earthquake. The largest recorded events within 20 kilometers of Saturday’s quake occurred on January 15th, 1967, and December 24th, 1967, with both registering a magnitude of 6.0 on the Richter Scale.
Has there been an increase in seismic activity?
Trinidad and Tobago and the surrounding region are very seismically active. Across the Eastern Caribbean, over 2,200 earthquakes are recorded annually. Since 1990, the University of the West Indies Seismic Research Centre has recorded an annual average of 280 earthquakes in the Trinidad and Tobago region (area bounded by 9.5°- 11.5°N & 59.5°W – 63.5°W). Of these 280 quakes, 50 of these seismic events are, on average, above magnitude 3.5.
Most earthquakes occur northwest of Trinidad in an area known as North of the Paria Peninsula, which has the second-highest seismicity in the Eastern Caribbean. According to the UWI SRC, approximately 65 events of magnitude 2.1 and above are located in the area annually.
However, the UWI SRC’s annual report for 2020 to 2021 states that regional seismic and volcanic activity has been elevated for several years.
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 that great quakes (M8.0+) on the Richter Scale have occurred every century in the region. The probability of another event at that level is high since the last >M8.0 earthquake occurred in 1843. While it is impossible to say definitively when the next great quake will occur in the region, the time since the last one is now more than 170 years ago.
It is important to note seismic activity *cannot* be predicted – meaning the precise time, date, magnitude, depth, etc., cannot be known ahead of time based on current research and technology.
Now is the time to create or go over your earthquake preparedness plan and know what to do during, before, and after an earthquake.
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In our region, earthquakes can strike at any time and any place, so it is important to know how to keep yourself safe when one strikes.
