Added by Erik West on March 26, 2013
The USGS reported a magnitude 5.42 earthquake in Mexico, just outside Santiago Pinotepa Nacional located near the southwest coast at 0709 local time (1104 GMT/UTC).
The local civil protection agency issued an alert and said they did not have any reports of damage in Mexico City, which was rocked by the earthquake. The state government also reported that no injuries or deaths were reported.
The local authority ordered some buildings to be evacuated as a precaution as a result of the earthquake, with its epicenter approximately 20 miles (32 km) below ground.
Mexico is located in one of the world’s most seismologically active regions. The underlying plates’ movement result in earthquakes and volcanic eruptions. The plates, called the North American plate and Cocos plate, move at approximately 50mm per year (1.9 inches).
A magnitude 8.1 earthquake on September 1985 struck Mexico City, killing more than 9,500 people. Volcanoes like Popocatépetl and Ixtaccíhuatl occasionally vent gases which can be seen from Mexico City.
The Richter scale is considered to be a simple numeric scale because it does not capture the overall source and magnitude of an earthquake. More recently, scientists have been measuring and reporting earthquake magnitudes using a scale called the Moment Magnitude Scale (MMS) which is measured in mega-watts (Mw) of energy.