11:56 AM – Moderate, Shallow Earthquake West of Trinidad

At 11:46 AM Tuesday 28th July 2020, a reviewed Magnitude 5.0 (Md or Mt) earthquake occurred 126.5 km WSW of Port of Spain, Trinidad and Tobago, 135.7 km WNW of San Fernando, Trinidad and Tobago.

This event occurred at a very shallow depth of 3 Kilometers. This information (above) has been reviewed by the U.W.I. Seismic Research Centre, the authority for seismic and volcanological information in the Eastern Caribbean.

Reviewed information from the University of the West Indies Seismic Research Centre concerning the M5.0 Earthquake west of Trinidad.
Reviewed information from the University of the West Indies Seismic Research Centre concerning the M5.0 Earthquake west of Trinidad.

This event was not widely reported felt. 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:

  1. The earthquake must occur beneath the ocean or cause material to slide in the ocean.
  2. The earthquake must be strong, at least magnitude 6.5.
  3. 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.
  4. 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.

Reviewed information from the USGS concerning the M4.3 (UWI SRC M5.0) Earthquake west of Trinidad.

The United States Geological Service (USGS) also recorded this quake at a magnitude 4.3 (Mb) at a shallow depth of 10.0 kilometres, slightly further west and south from the UWI SRC solution.

Preliminary information from FUNVISIS concerning the M4.3 (UWI SRC M5.0) Earthquake west of Trinidad.
Preliminary information from FUNVISIS concerning the M4.3 (UWI SRC M5.0) Earthquake west of Trinidad.

The Venezuelan Foundation for Seismological Research (FUNVISIS) also recorded this quake at a magnitude 4.3 (Mw) at a shallow depth of 2.3 kilometres, slightly further west and south from the UWI SRC solution.

Seismicity in this area is very common, with 145 quakes occurring with 10 kilometers of the epicenter of this quake since 1960. The strongest event occurring within this 10-kilometer area was the August 21st 2018 magnitude 6.9 earthquake. Most quakes in this area register below magnitude 5.0, making this quake the third strongest quake within a 10 km, tied with January 9th, 1992.

This quake like occurred along the strike-slip El Pilar Fault Zone, based on its location and shallow depth, in seismic zone 2.

This zone comprises part of the boundary between the Caribbean and the South American plate. The events that have their origin in the fault are shallow – less than 50 kilometers depth, and they are usually characterized mainly by right lateral strike slip along the northern coast of South America.

The El Pilar Fault, in the vicinity of Carúpano, has a number of smaller, conjugate or perpendicular faults which frequently produce earthquake swarms. This location is hypothesized to have a higher frequency of earthquakes compared to other locations along the El Pilar Fault Zone due to a kink in the fault system, with higher stress levels building in this zone than elsewhere.

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.

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