Every year, several earthquakes are recorded around the world, some causing death and destruction. This Thursday (7), one hit California, causing interruption of services and leaving residents on alert.
A tsunami warning was issued, but authorities after about an hour.
in California cities. Residents recorded lights swinging and swimming pools overflowing.
Learn more about earthquakes below.
What are earthquakes? Why do they happen?
NASA, the United States space agency, defines an earthquake as an “intense shaking of the Earth’s surface”.
The United States Geological Survey (USGS) describes the phenomenon as “the shaking of the ground caused by a sudden slip on a fault” on the Earth’s surface.
According to the agency, during an earthquake, “tensions in the Earth’s outer layer push against the sides of the fault.” Thus, “tension increases and the rocks slide suddenly, releasing energy in waves that travel through the Earth’s crust and cause the shaking that we feel during an earthquake”, he explains.
How are earthquakes measured?
which monitor the seismic waves that travel through the Earth after tremors.
Scientists have used the Richter Scale for many years to measure earthquakes, but now largely follow the “moment magnitude scale,” which the USGS says is a more accurate measurement.
The most recent significant earthquake to cause widespread damage was reported on October 7, 2023, west of the city of Herat, Afghanistan. It was a 6.3 magnitude tremor that left more than 2,000 people dead, according to authorities.
