teph·​ra | \ ˈte-frə How to pronounce tephra (audio) \

Definition of tephra

: solid material ejected into the air during a volcanic eruption especially : ash entry 2 sense 2b

Examples of tephra in a Sentence

Recent Examples on the Web The chemical composition of the tephra shards in the ice cores matched that of material from Okmok volcano in Alaska. Kate Baggaley, Popular Science, "A massive volcanic eruption may have contributed to the rise of the Roman Empire," 25 June 2020 But volcanologists haven’t been sure precisely when the eruption happened; radiocarbon dates on organic material buried beneath the tephra only narrowed it down to a window between 190 BCE and 50 CE. Kiona N. Smith, Ars Technica, "The volcano that caused famines in ancient Rome? It was in Alaska," 22 June 2020 Some 630,000 years ago, the supervolcano beneath Yellowstone National Park in Wyoming recorded its last catastrophic eruption, forming a caldera that nearly spans the park’s width and belching a thick layer of ash, or tephra, across North America. Paul Voosen, Science | AAAS, "Yellowstone’s massive volcano could erupt more frequently than scientists thought," 25 Oct. 2017 Understanding tephra is usually harder than finding it. Erin Mckittrick, Alaska Dispatch News, "Digging up Alaska’s volcanic secrets," 29 July 2017 That volcano last erupted in 1985 producing lava flows with minor tephra. Erik Klemetti, WIRED, "Expanded evacuations as the Kirishima eruption continues," 31 Jan. 2011

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'tephra.' 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 tephra

circa 1944, in the meaning defined above

History and Etymology for tephra

New Latin, from Greek, ashes; akin to Sanskrit dahati it burns — more at foment

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Time Traveler for tephra

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The first known use of tephra was circa 1944

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Cite this Entry

“Tephra.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/tephra. Accessed 22 Oct. 2020.

More from Merriam-Webster on tephra

Britannica.com: Encyclopedia article about tephra

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