In the context of seismic activity of earth what are swarms ........

Geography Geomorphology

In the context of seismic activity of earth, what are swarms?

The amount of energy released in earthquake.

Abrupt movement of geological materials downhill in response to gravity.

Numerous earthquakes that occur locally over an extended period, without a clear sequence of high-intensity main quakes.

A more or less continuous motion in the Earth that is unrelated to an earthquake and that has a period of 1.0 to 9.0 seconds.

Recent Context: Delhi is facing small but frequent shocks and this phenomenon is being compared to Palghar earthquake swarms (Maharashtra).

Option (a) is not correct: The amount of energy released in an earthquake is known as seismic energy.
Option (b) is not correct: An abrupt movement of geological materials downhill in response to gravity is known as a landslide. Landslides can be triggered by an earthquake or other natural causes.
Option (c) is correct: According to the Swiss Seismological Service, swarms are numerous earthquakes that occur locally over an extended period, without a clear sequence of high-intensity main quakes, preceded and succeeded by lower-intensity foreshocks and aftershocks. When seismic energy piles up inside the Earth and is released in small amounts from certain points, such a series of earthquakes can occur. Sometimes, these are also accompanied by acoustic or sound emissions.
Option (d) is not correct: A more or less continuous motion in the Earth that is unrelated to an earthquake and that has a period of 1.0 to 9.0 seconds is called a microseism. It is caused by a variety of natural and artificial agents.