Tremor on the coast and interior of SP had repercussions on the capital; understand phenomenon

The earthquake that occurred this Friday morning (16), on the coast and in the interior of São Paulo, also had repercussions in the capital and metropolitan region, according to the Seismology Center of the University of São Paulo.

Residents of municipalities such as Taboão da Serra, Cotia, Carapicuíba, Osasco and even in the capital reported having noticed the shock, through social networks.

The researchers claim that the earthquake of magnitude 4.0 on the Richter scale (which goes up to nine) had as its epicenter the cities of Miracatu, Iguape and Itariri.

Shakes of this magnitude can be “slightly felt” up to a distance of one hundred kilometers or more, according to the research center – the city of Miracatu is 140 km away from the capital.

The region where the tremors were felt, according to experts, is prone to tremors. Scientists, however, are still investigating what motivated the phenomenon this morning, recorded around 8:22 am.

“Brazil is in a privileged position, in the center of the South American tectonic plate, but that does not mean it is free from feeling occasional shocks, caused by the release of tension generated by the movement of the plate”, says Bruno Colaço, seismologist at the USP Center .

Also according to USP, magnitude 4 is not enough to cause concern. Effects at the epicenter may include small cracks in plaster or falling tiles on houses. But the impact scares residents. “In general, these tremors happen in sparsely populated regions. But when they occur in urban areas, everyone is scared. It is normal for this to happen, but structural damage rarely occurs”, says Colaço.

The south coast of São Paulo is a relatively active zone in terms of tremors in relation to other regions of the State. In July 1946, a tremor was recorded in Cananeia, with a magnitude of 4.6 on the Richter scale. Technician José Roberto Barbosa, who also works at the USP Seismology Center, explains that magnitude 2 or 3 tremors are more common.

Experts clarify that these tremors are not considered earthquakes. “Earthquakes are catastrophic events. On average, twice a year magnitudes above 4 occur somewhere in Brazil”, explains Barbosa.

Several reports showed the residents’ apprehension. Businesswoman Ana Paula Bertoldi Gato, 52, told Estadão that she felt the vibrations in Registro, in the Ribeira Valley. “I was in the kitchen with my daughter and the windows started banging. I thought it was a strong wind. The walls and floor began to shake. Cupboards and glasses began to rattle. It didn’t stop, it was about ten seconds. I ran out onto the porch of my house to see if a truck was passing by,” she says.

“Guys, I ‘was’ teaching and I felt a tremor in the window and on the blackboard. I thought I was going crazy, I went on Facebook and saw a woman saying that she felt an earthquake in Cajati and I found out that there really was an earthquake in Miracatu”, wrote an internet user, who identified himself as Professor Yuri Pimentel.