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Paleoclimatology (thesaurus)

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Concept information

Terme préférentiel

tephra  

Définition

  • Ejecta (from Latin 'things thrown out'; singular ejectum) are particles ejected from an area. In volcanology, in particular, the term refers to particles including pyroclastic materials (tephra) that came out of a volcanic explosion and magma eruption volcanic vent, or crater, has traveled through the air or under water, and fell back on the ground surface or on the ocean floor. Typically in volcanology, ejecta is a result of explosive eruptions. In an explosive eruption, large amounts of gas are dissolved in extremely viscous lava; this lava froths to the surface until the material is expelled rapidly due to the trapped pressure. Sometimes in such an event a lava plug or volcanic neck forms from lava that solidifies inside a volcano's vent, causing heat and pressure to build up to an extreme with no way to escape. When the blockage breaks and cannot sustain itself any longer, a more violent eruption occurs, which allows materials to be ejected out of the volcano. (Adapted from: https://en.wikipedia.org/wiki/Ejecta)

Concept générique

Synonyme(s)

  • volcanic ash layer

Traductions

  • français

  • éjecta volcanique
  • pyroclaste

URI

http://data.loterre.fr/ark:/67375/QX8-45XRP6T3-B

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