Yesterday Mexico experienced another large earthquake (magnitude 6.4), the latest in a series of large events to hit the western coast of the country, about 300km away from Mexico City. This is the region where a part of the Pacific tectonic plate is being pushed under the north American plate along a large subduction zone fault (a large fracture in the Earth).
Interestingly, most of these earthquakes occurred along a portion of the fault that has not experienced an earthquake in recent times. So are these earthquakes filling in a gap in the seismic activity along the fault in the so called Guerrero Seismic Gap? And how do these relate to the observed slow slip (events that occur over weeks to months instead of seconds) earthquakes in the region? And ultimately how will these affect the seismic threat to Mexico City?
Figure courtesy of David Bekaert.