Definition of phreatomagmatic in English:

phreatomagmatic

adjective

Geology
  • (of a volcanic eruption) in which both magmatic gases and steam from groundwater are expelled.

    • ‘These are commonly present as pyroclastic deposits rather than lava because their early arrival favours interaction with groundwater to produce phreatomagmatic eruptions, and/or because they have higher volatile contents.’
    • ‘A similar degree of compositional variation between pyroclast glasses of phreatomagmatic pyroclastic rocks and intruding dykes has been recognized from the vent remnant of Szigliget, western Hungary.’
    • ‘After 1 August phreatomagmatic activity resumed and continued at a gradually diminishing rate until 5 August.’
    • ‘These rafts were originally surface phreatomagmatic deposits, which were probably wet when they slumped into the vent complex.’
    • ‘Mud and sand volcanoes are positive topographic features that have many of the aspects of normal phreatomagmatic volcanism resulting from explosive interaction between hot magma and water.’

Origin

Mid 20th century: from Greek phrear, phreat- ‘a well’ + magmatic (see magma).

Pronunciation

phreatomagmatic

/frēˌadəmaɡˈmadik/