Meaning of phreatic in English:


Pronunciation /frɪˈatɪk/


  • 1Geology
    Relating to or denoting underground water in the zone of saturation (beneath the water table).

    Compare with vadose

    ‘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.’
    • ‘Gravitational sediments can enter a cave system in the form of entrance talus material, colluvium, roof fall, or phreatic infiltrates.’
    • ‘In the case of the Kendrick Formation, however, the system was closed by early compaction of surrounding clays, and diagenesis apparently occurred in a marine phreatic environment.’
    1. 1.1(of a volcanic eruption) caused by the heating and expansion of groundwater.
      ‘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.’
      • ‘That in 4390 was large and complex, with eruptions at the central vent and radial fissures on the flank, submarine and phreatic eruptions, and pyroclastic flows.’
      • ‘Eruptions after 26 October 1986 were phreatic steam explosions, not direct expressions of magma.’


Late 19th century from Greek phrear, phreat- ‘a well’ + -ic.