The term glaciovolcanism refers to volcanic eruptions in which there is interaction between eruptive materials (lava or pyroclastic debris) and ice or snow. Glaciovolcanism is also referred to as volcano-ice interaction, and includes subglacial volcanism (eruptions beneath glaciers), ice-marginal volcanism (eruptions at the edges of glaciers), and supraglacial eruption (eruptions onto the surfaces of glaciers). Glaciovolcanism is most prevalent at high latitudes and altitudes because these regions are likely to be extensively glaciated.
Interaction between volcanoes and ice is recorded as landforms whose shapes are dependent on the eruptive and environmental conditions, including magma composition, magma eruption parameters (such as temperature, effusion rate, and length of the eruption), vent type (fissure or point source), type of ice (warm or cold-based), ice characteristics (such as thickness, distribution, and permeability), amount of trapped water, and bedrock/surrounding topography. Understanding these eruptive processes and the resulting landforms is useful and interesting because:
(a) glaciovolcanic features can help in delineating past ice distributions, making them useful in climatic studies;
(b) eruptions in contact with ice can rapidly generate large quantities of meltwater, which can produce floods (jökulhlaups) and lahars;
(c) many glaciovolcanic features are steep, unstable, and subject to mass movements following ice removal;
(d) in some parts of the world (e.g. Iceland, parts of British Columbia, etc.), glaciovolcanic landforms are prominent landscape features, and;
(e) it is probable that there are genetic links between deglaciation (ice removal) and volcanic activity.
The study of glaciovolcanism is relatively new. Early accounts described unusual , flat-topped, steep-sided volcanoes in Iceland and suggested that they formed through eruptions beneath ice. The first English language description of glaciovolcanic products was published by Mathews (1947); he decribed landforms from the Tuya Butte volcanic field in northwestern British Columbia, and attributed shapes of the volcanoes there to eruption into ice-confined lakes. These descriptions also introduced the usage of the term tuya for flat-topped, steep-sided volcanoes formed by subglacial eruption. Since then, glaciovolcanic products have been identified in Iceland, British Columbia, the United States Cascade Range, Alaska, Antarctica, South America, and Hawaii, and on the planet Mars.