These volcanoes aren’t made up of fire and molten rocks – these are sand volcanoes that “erupt” during an earthquake as the ground shifts.
A sand volcano usually occurs after an earthquake. It is formed when sand is thrown up to the surface from a central position. As the sand is ejected it builds up in to a cone, taking on the appearance of a volcano as the sand comes to rest on its sides. A crater forms which can range in size from the tiny, just a few milimeters, to one which can extend to several meters.
In order for a sand volcano (also known as a sand blow) to form, stress must be applied to the earth in the locality. The soil loses its strength and although it does not actually become a liquid, it certainly behaves like one. It is most likely to happen when the soil is saturated, loose and sandy. Soil is often saturated in areas which are below sea level.
To read more and see more examples, click here.