Maar

For other uses, see Maar (disambiguation).
Look up maar in Wiktionary, the free dictionary.
The ten-day phreatomagmatic eruption that formed the Ukinrek maars
The Devil Mountain Lakes on the Seward Peninsula in western Alaska – the largest maar-based lakes in the world

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 maar.[1]

Maars range in size from 20 to 3,000 m (66 to 9,800 ft) across and from 5 to 200 m (20 to 700 ft) deep.[2][3] Most maars fill with water to form natural lakes. Most maars have low rims composed of a mixture of loose fragments of volcanic rocks and rocks torn from the walls of the diatreme.[3]

  1. ^ David S.G. Thomas and Andrew Goudie (eds.), The Dictionary of Physical Geography (Oxford: Blackwell, 2000), 301. ISBN 0-631-20473-3.
  2. ^ Lorenz, V. (October 1986). "On the growth of maars and diatremes and its relevance to the formation of tuff rings". Bulletin of Volcanology. 48 (5): 265–274. Bibcode:1986BVol...48..265L. doi:10.1007/BF01081755. S2CID 128423499.
  3. ^ a b Lorenz, Volker (January 2007). "Syn- and posteruptive hazards of maar–diatreme volcanoes". Journal of Volcanology and Geothermal Research. 159 (1–3): 285–312. Bibcode:2007JVGR..159..285L. doi:10.1016/j.jvolgeores.2006.02.015.