maare

Maare are circular depressions in the ground, typically found in arid and semi-arid regions. They are formed by phreatomagmatic eruptions, which occur when hot magma comes into contact with groundwater. The rapid heating of the water causes it to flash into steam, leading to an explosive expansion that excavates the surrounding rock and soil. Unlike volcanic craters which are formed by the expulsion of molten rock, maare are characterized by their broad, shallow bowls and lack of significant lava flows.

The size of maare can vary considerably, from a few hundred meters to several kilometers in diameter. Their depth is usually less than their width. The rims of maare are often composed of ejected material, which can include blocks of rock and ash. Over time, maare can fill with water, forming maar lakes, which can be important habitats for wildlife.

Maare are common geological features in volcanic fields around the world. Famous examples include the Eifel region of Germany, the San Francisco Volcanic Field in Arizona, USA, and the Auckland Volcanic Field in New Zealand. The study of maare provides valuable insights into volcanic processes, particularly those involving the interaction of magma and water. They are also important features in landscape studies and can pose hazards in areas with active volcanism due to their explosive formation.