Swarm (seismic swarm)

A localized surge of earthquakes, with no one shock being conspicuously larger than all other shocks of the swarm. Seismic swarms typically last longer than more typical earthquake sequences that consist of a main shock followed by significantly smaller aftershocks. Seismic swarms occur in a variety of geologic environments. They are not known to be indicative of any change in the long-term seismic risk of the region in which they occur.