An earthquake measuring 8.0 occurred this morning, September 8 at 6:49 am Italian, off the Pacific coast of Mexico.
Location of the 8.0 magnitude earthquake that occurred this morning, September 8, 2017 at 6:49 Italian time, off the Pacific coast of Mexico.
The data received in real time in the seismic monitoring room of the National Institute of Geophysics and Volcanology (INGV) made it possible to locate the event: epicenter in the sea, near the coast of Chiapas, Mexico, with geographic coordinates (lat, lon) 15.13, -93.69 at a depth of 72 km.
Seismogram of the 8.0 magnitude earthquake that occurred this morning, 8 September 2017 at 6:49 Italian time, off the Pacific coast of Mexico. BRMO Station (Bormio, SO) of the National Seismic Network.
The earthquake occurred in a seismically very active region where earthquakes are frequent due to sliding of the oceanic Cocos plate under the North American and Caribbean plates.
Seismicity of the Central American region. Earthquakes like today's occur from the movement of the Cocos plate as it flexes and slides under the North American and Caribbean plates. Epicenters in red represent shallower earthquakes, while those in green, which occur within Mexico and Guatemala, are deeper.
Due to the high magnitude and characteristics of the earthquake, a tsunami warning was issued for Mexico and neighboring states a few minutes after the event. In fact, tsunami waves were then detected at Mexican tide gauge stations. The figure below shows the oscillations of the sea level measured by the tide gauge of Salina Cruz, where variations of about 1 meter were detected with respect to the mean sea level.
Sea level fluctuations measured at the tidal station of Salina Cruz, Mexico. The swell is due to the tide. The arrival of the tsunami wave can be seen around 05:15 with a wave period of about 35 minutes. The long-term oscillation clearly visible before the arrival of the tsunami is due to the tide.
The INGV Tsunami Warning Center (CAT), responsible for monitoring earthquake-induced tsunamis in the Mediterranean, analyzes seismic and sea level data from all over the world. While not sending related alerts to international organizations for events outside the Mediterranean region, it still carries out analyzes on a global scale for training purposes.
Link to the INGV Earthquake Blog:
https://ingvterremoti.wordpress.com/2017/09/08/terremoto-m8-0-al-largo-del-messico-del-8-settembre-ore-0649-italiane/