After the latest California earthquake, scientists are starting to realize that their understanding may be off. Initial studies show that epicenters emerge 15 miles from the earth's crust. No earthquake epicenter had appeared lower. However, the latest research shows that they can appear even deeper.
But the greatest fear of this discovery indicates that the source of a quake can be located in the magma region of the earth. This semi-liquid region would allow the shock waves to travel further and generate more force.
"That got us thinking that if earthquakes want to get big, one way of achieving that is by penetrating deeper, "said seismologist Jean Ampuero. "The big question is: If the next, larger earthquake happens if it manages to penetrate deeper than we think, it may be bigger than we expect."
Indeed, his fear is valid with the largest Earthquake ever recorded emerged just less than 15 miles. The reverse is also true as a weak earthquakes' epicenter is usually closer to the crust. This rigid area of the earth does not allow as much energy and vibration to travel through it. Due to its closeness to the surface, the waves do not travel a significant distance.