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Related to foreshock: tsunami, aftershock


A minor tremor of the earth that precedes a larger earthquake originating at approximately the same location.


(Geological Science) a relatively small earthquake heralding the arrival of a much larger one. Some large earthquakes are preceded by a series of foreshocks. Compare aftershock


(ˈfɔrˌʃɒk, ˈfoʊr-)

a relatively small earthquake that precedes a greater one by a few days or weeks and originates at or near the focus of the larger earthquake.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.foreshock - a tremor preceding an earthquake
earth tremor, microseism, tremor - a small earthquake
References in periodicals archive ?
Even if a foreshock occurs, there is no means to identify whether it is actually a aACAyforeshock' and that a major quake will follow.
After performing required revisions, including deleting aftershock and foreshock through spatial and temporal windows method [8], homogenization of magnitudes, determination of year, completion of catalogue and etc.
Conditions in the foreshock change in response to solar particles streaming in from the sun, moving magnetic fields and a host of waves, some fast, some slow, sweeping through the region.
Figure 4 shows that the 1993 focal depth started with more than 10 km for foreshocks, no foreshock having less than 10 km depth.
Few aftershocks were recorded, but it was preceded by a foreshock of M 4.
Their careers ran parallel at Deloitte & Touche LLP and Ernst and Young, and later they joined forces at Foreshock, a consulting application service company.
The foreshock sent people scrambling, and the main shock arrived with such fury that it flattened crowded rooming houses.
Kate Hutton, a seismologist at the California Institute of Technology in Pasadena, said there was a one-in-20 chance that Tuesday's quake was a foreshock to a larger quake that could hit within five days.
23 is now believed to have been the foreshock of the stronger earthquake that struck Nov.
12am local time, a foreshock happened in the San Francisco Bay area.