Definition of phreatic in English:

phreatic

Line breaks: phre|at¦ic
Pronunciation: /frɪˈatɪk
 
/

adjective

Geology
  • 1Relating to or denoting underground water in the zone of saturation (beneath the water table). Compare with vadose.
    More example sentences
    • For example, they may occur in the continental realm above the water table - the vadose zone; or in the permanently shallow saturated zone - the phreatic zone, in either freshwater or marine conditions.
    • Conversely, grainstone fabrics of the upper sequences show the development of bladed and equant calcite cement around oolites, indicative of a primary cementation in a freshwater phreatic environment.
    • In 1990 John Cordingley found that the sump had disappeared and that the passage continued along a tube to a step up into a small phreatic rift.
  • 1.1(Of a volcanic eruption) caused by the heating and expansion of groundwater.
    More example sentences
    • This type of eruption, called a phreatic eruption, is characterized by a volcanic crater that goes beneath the level of the surrounding landscape and is encircled by a wide, low ring of volcanic debris.
    • This eruption began in July 1995 with phreatic explosions following 3 years of precursory seismic activity.
    • The characteristic tuffs of the Balder Formation originate from phreatic eruptions from the incipient continental rift zone between Eurasia and Greenland to the west.

Origin

late 19th century: from Greek phrear, phreat- 'a well' + -ic.

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