At 3:12 PM Sunday 4th October 2020, a preliminary Magnitude 5.2 (Md or Mt) earthquake occurred 51 km N of Arima, Trinidad and Tobago, 56 km NE of Port of Spain, Trinidad and Tobago and, 57 km W of Scarborough, Trinidad and Tobago.
This event occurred at a shallow depth of 10 Kilometers. This information (above) is preliminary by the U.W.I. Seismic Research Centre, the authority for seismic and volcanological information in the Eastern Caribbean. This information may change when additional data is processed by a seismologist.
There have been no initial reports of damages or injuries.
This event was widely reported felt across Trinidad and Tobago Felt reports also extended to parts of Northeastern Venezuela, Grenada and St Vincent and the Grenadines. 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 in the ocean.
- The earthquake must be strong, at least magnitude 6.5.
- The earthquake must rupture the Earth’s surface and it must occur at shallow depth – less than 70 KM below the surface of the Earth.
- The earthquake must cause vertical movement of the seafloor (up to several meters).
None of these conditions occurred.
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.
The European Mediterranean Seismological Centre (EMSC) also recorded this quake at a magnitude 4.8 at a moderate depth of 60 kilometers, slightly closer to Trinidad but much deeper than the UWI SRC solution.
The Venezuelan Foundation for Seismological Research (FUNVISIS) also recorded this quake at a magnitude 4.9 (Mw) at a deeper depth of 21.0 kilometers, in a similar location to the UWI SRC solution.
Seismicity in this area is common, with 27 quakes occurring with 10 kilometers and 121 earthquakes occurred within 20 kilometers of the epicenter of this quake since 1960.
The strongest event occurring within the 10-kilometer area was a magnitude 5.1 earthquake on May 3rd, 1997 and within the 20-kilometer area, a magnitude 5.2 earthquake on December 20th, 1962. Most quakes in this area register below magnitude 5.0, making this quake the strongest quake within a 10 kilometers and typing for the strongest quake within 20 kilometers in recent recorded history.
This quake like occurred in seismic zone 1, North of Trinidad and Tobago.
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. This is likely where this event occurred.
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. This area typically produces light (M4.0-4.9) or moderate (M5.0-5.9) magnitude earthquakes. Earthquakes in this zone tend to produce less aftershocks than earthquakes elsewhere across Trinidad and Tobago.
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 quakes (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.