GEOLOGY

Detailed explanation-1: -Foreshocks are earthquakes that precede larger earthquakes in the same location. An earthquake cannot be identified as a foreshock until after a larger earthquake in the same area occurs. Aftershocks are a sequence of earthquakes that happen after a larger mainshock on a fault.

Detailed explanation-2: -The foreshock definition states that they are smaller quakes that occur prior to the mainshock. Foreshocks are smaller in magnitude than mainshocks and aftershocks, although they do result in the shaking of the earth. Foreshocks cannot be labeled as such, until a larger quake occurs in the same region.

Detailed explanation-3: -Usually, for a preceding quake to be considered a foreshock, seismologists also look for the epicenter to be in the same general area as the mainshock – at a distance no more than a few times the length of the fault section that moved during the mainshock.

Detailed explanation-4: -Aftershocks can continue over a period of weeks, months, or years. In general, the larger the mainshock, the larger and more numerous the aftershocks, and the longer they will continue. Foreshocks are relatively smaller earthquakes that precede the largest earthquake in a series, which is termed the mainshock.