A lava bomb is a globule of molten rock (tephra) larger than 2.5 inches (64 mm) in diameter, formed when a volcano ejects viscous fragments of lava during an eruption. They cool into solid fragments before they reach the ground. Lava bombs can be thrown many kilometres from an erupting vent, and often acquire aerodynamic shapes during their flight. Tephra, as a generic term, refers to air-fall material produced by a volcanic eruption - regardless of composition or fragment size. ... Eruption redirects here. ... The pitch drop experiment at the University of Queensland. ... Look up lava, Aa, and pahoehoe in Wiktionary, the free dictionary. ...

If the outside of a lava bomb solidifies during its flight, it may develop a cracked outer surface as the interior continues to expand. This type of lava bomb is known as a breadcrust bomb. If the bomb remains molten when it strikes the ground, it may form a distinctively-shaped cow-dung bomb.

Volcanic bombs are a significant volcanic hazard, and can cause severe injuries and death to people in an eruption zone. One such incident occurred at Galeras volcano in Colombia in 1993; six people near the summit were killed and several seriously injured by lava bombs when the volcano erupted unexpectedly. Galeras is a volcano in Colombia, near the city of Pasto. ... 1993 (MCMXCIII) was a common year starting on Friday of the Gregorian calendar and marked the Beginning of the International Decade to Combat Racism and Racial Discrimination (1993-2003). ...

External links

Volcanic bombs are stones or rocks that are boiling hot, they are tossed out of the volcano and can cause major damage.

http://www.gc.maricopa.edu/earthsci/imagearchive/bombs.htm

• http://volcanoes.usgs.gov/Products/Pglossary/bomb.html