
An explosion crater is a type of
crater formed when material is ejected from the surface of the ground by an explosive event at or immediately above or below the surface.
A crater is formed by an explosive event through the displacement and ejection of material from the ground. It is typically bowl-shaped. High-pressure gas and
shock wave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a me ...
s cause three processes responsible for the creation of the crater:
* Plastic deformation of the ground.
* Projection of material (
ejecta
Ejecta (from the Latin: "things thrown out", singular ejectum) are particles ejected from an area. In volcanology, in particular, the term refers to particles including pyroclastic materials ( tephra) that came out of a volcanic explosion and magm ...
) from the ground by the explosion.
*
Spallation of the ground surface.
Two processes partially fill the crater back in:
* Fall-back of ejecta.
* Erosion and landslides of the crater lip and wall.
[P. W. Cooper. ''Explosives Engineering''. Wiley-VCH. ]
The relative importance of the five processes varies, depending on the height above or depth below the ground surface at which the explosion occurs and on the composition of the ground.
Examples
One of the largest explosion craters in Germany is in the borough of
Prüm. It was caused by a huge
explosion in 1949, in which an
ammunition depot exploded due to unknown causes and large parts of the town were destroyed.
References
See also
*
Hydrothermal explosion, caused by rapid heating of groundwater by volcanic sources
*
Maar, a crater caused by a volcanic explosion
*
Pseudocrater, a volcanic crater formed by a steam explosion
*
Subsidence crater, a depression in the ground formed by collapse of a void below the surface
*
Impact crater
An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact crater ...
, a depression formed by excavation following a hypervelocity impact
*
Volcanic crater
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