Tremor or earthquake? Understand event of magnitude 3.3 registered in RJ

A tremor measuring 3.3 on the Richter scale was recorded on the coast of Rio de Janeiro, near the municipality of Maricá, at 5:31 am this Thursday (21).

The event was captured by RSBR (Brazilian Seismographic Network) stations and analyzed by the USP Seismology Center. There were no reports that the population felt the shock.

Difference between tremor and earthquake
Although the terms are often used interchangeably, the technical distinction lies in the intensity of the phenomenon.

According to the SGB (Brazilian Geological Survey), events of low intensity and reduced magnitude are classified as earthquakes or earthquakes.

The term earthquake is technically reserved for shocks of greater magnitude and rupture extension.

In the case of the record on the coast of Rio de Janeiro, the seismologist at the National Observatory, Dr. Gilberto Leite, classifies the event as common in Brazil, without representing a significant risk to the population.

Why do tremors occur in Brazil?
Brazil is located in the center of the South American Plate, which results in intraplate earthquakes, generally of small to moderate intensity.

However, the southeastern margin of the country is considered the main offshore seismic zone, where small tremors frequently occur due to tectonic stresses in the Earth's crust.

Earthquake in RJ: see what we know about the seismic event

The rapid location of the 3.3 magnitude event was possible thanks to the constant monitoring work of RSBR, which uses internet transmissions and satellites to process data in real time.

Source: CNN