fore·​shock | \ ˈfȯr-ˌshäk How to pronounce foreshock (audio) \

Definition of foreshock

: any of the usually minor tremors commonly preceding the principal shock of an earthquake

Examples of foreshock in a Sentence

Recent Examples on the Web The strongest two — a 6.8 foreshock and the 7.1 mainshock — happened just four minutes apart. Sam Gross, USA TODAY, "Nevada 'dodged a bullet' when 6.5 earthquake struck in a remote area, seismologist says," 16 May 2020 There were thousands of foreshocks and aftershocks felt throughout the region. CBS News, "Earthquake and aftershock shake San Jose area," 16 July 2019 Vanacore says that this latest series of events seems to be more of a traditional earthquake sequence rather than a swarm, with a bigger temblor surrounded by its own entourage of smaller foreshocks and aftershocks. National Geographic, "Why so many earthquakes are rocking Puerto Rico," 11 Jan. 2020 When solar wind storms strike Earth, that solar radiation first crashes into a part of Earth’s magnetic field called the foreshock. Jennifer Leman, Popular Mechanics, "Listen to What Happens When Solar Storms Hit Earth's Magnetic Field," 25 Nov. 2019 However, that quake would now be considered a foreshock to the Friday night temblor. Jason Green, The Mercury News, "New magnitude 7.1 earthquake strikes Southern California, felt in Bay Area," 5 July 2019 When that happens, the first quake is called a foreshock, and the second temblor is called a main shock. Maya Wei-haas, National Geographic, "Earthquake safety tips," 20 Sep. 2019 Those precursor events were the laboratory equivalent of the seismic waves produced by foreshocks before an earthquake. Quanta Magazine, "Artificial Intelligence Takes On Earthquake Prediction," 19 Sep. 2019 The events of the last couple of weekends might simply be foreshocks. George Schroeder, USA TODAY, "Football Four: Will Tua Tagovailoa injury impact College Football Playoff race?," 20 Oct. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'foreshock.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of foreshock

1902, in the meaning defined above

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Time Traveler for foreshock

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The first known use of foreshock was in 1902

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Statistics for foreshock

Last Updated

24 May 2020

Cite this Entry

“Foreshock.” Dictionary, Merriam-Webster, Accessed 11 Jul. 2020.

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