A maar is a broad, low- relief volcanic crater caused by a phreatomagmatic eruption (an explosion which occurs when groundwater comes into contact with hot lava or magma). A maar characteristically fills with water to form a relatively shallow crater lake, which may also be called a …

What is a Maar? A maar is a shallow volcanic crater with steep sides that is surrounded by tephra deposits. The tephra deposits are thickest near the crater and decrease with distance from the crater.

Apr 17, 2023 · Maars and tuff rings are low-standing volcanoes with wide, bowl-shaped craters. They commonly have a donut-like profile, and may be breached. Their low edifices consist of shallowly-dipping deposits of tuff made mostly of ash and angular, nonvesicular pebble-sized pyroclasts (lapilli).

A maar is a low-relief, broad volcanic crater formed by shallow explosive eruptions. The explosions are usually caused by the heating and boiling of groundwater when magma invades the groundwater table. Maars often fill with water to form a lake.

A diatreme, sometimes known as a maar-diatreme volcano, is a volcanic pipe associated with a gaseous explosion. When magma rises up through a crack in Earth's crust and makes contact with a shallow body of groundwater, rapid expansion of heated water vapor and volcanic gases can cause a series of explosions.

Maar, small crater blasted by a low-temperature volcanic explosion and not associated with a volcanic cone. The rim of ejected fragmental material around the crater often is very low and inconspicuous.

May 15, 2013 · Maars are craters left behind after violent volcanic steam explosions, sparked when rising magma runs into groundwater, which then blows up like a bomb. "When water turns to steam, it expands its...

Oct 4, 2012 · Magma creeps up through a crack in the Earth's crust and mixes with water, setting off a series of explosions — as many as a few each hour for several weeks. When the action stops, a...

Apr 15, 2011 · Maar-diatreme volcanoes are produced by explosive eruptions that cut deeply into the country rock. A maar is the crater cut into the ground and surrounded by an ejecta ring, while the diatreme structure continues downward and encloses diatreme and root zone deposits.

Jan 7, 2024 · What Are Maars and How Do They Form? Maars are shallow, nearly rounded to oval bowl-shaped volcanic craters surrounded by low rims of fragmental debris or pyroclasts. These landforms are hydrovolcanic and usually monogenetic.