But earthquakes in California and Mexico differ in ways that are important to understand -- if we are to learn lessons that allow us to better prepare for them in the future. Jean-Paul AmpueroFirst, the tectonic activity in each area is different: California sits at the boundary between two plates that rub each other horizontally. The plates off the shore of Mexico and the rest of the Pacific "ring of fire," an area of intense seismic activity, rub against each other vertically. As a result, Mexico has bigger earthquakes. Because of this difference of distance to the major fault, it is more challenging to build an earthquake early warning system for Los Angeles than for Mexico City, which means that the time available to declare a warning is much shorter in California.

Source: CNN September 20, 2017 17:26 UTC