Along divergent boundaries like the mid-Atlantic ridge and the East Pacific Rise, earthquakes are common, but restricted to a narrow zone close to the ridge, and consistently at less than 30 km depth. Shallow earthquakes are also common along transform faults, such as the San Andreas Fault.
Explanation:
When the earthquake depth is very shallow, it can be reported as a negative depth. Earthquake depths are calculated relative to the World Geodetic System of 1984 (WGS84) geoid, mean sea-level, or the average elevation of the seismic stations that provided arrival-time data for the earthquake location.
False, igneous rocks may classified by chemical composition but may not be crystallized together in the same rock. SO there are always different minerals in igneous rocks.
