Volcanic Erupotions
volcanic eruption, an eruption of molten rock, hot rock fragments, and hot gases through a volcano, which is a vent in a planet’s or satellite’s crust.
Volcanic eruptions can cause disastrous loss of life and property.
They range from relatively gentle eruptions, as typically seen in Hawaiian volcanoes, to massively destructive ones,
such as the eruption of Vesuvius that destroyed Pompeii in 79 CE. Volcanic eruptions have captured the imagination of people over millennia,
and they feature in several mythologies as well as works of fiction. These eruptions also play a role in climate change,
with expelled gases such as carbon dioxide contributing to global warming, while ash, dust, and gases such as sulfur dioxide can drive global temperatures down.
Volcanic eruptions occur as a result of heat moving under Earth’s surface. They often begin with an accumulation of gas-rich magma (molten underground rock) in reservoirs near Earth’s surface,
though they may be preceded by emissions of steam and gas from small vents in the ground. Small earthquakes, which may be caused by a rising plug of dense,
viscous magma oscillating against a sheath of more permeable magma, may also signal volcanic eruptions, especially explosive ones.
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