Volcanic ash

Volcanic ash consists of fragments of rock, <a href="/facts/Mineral/LkUFbNmv">mineral</a> <a href="/facts/Crystal/e2R2mk3E">crystals</a>, and <a href="/facts/Volcanic_glass/MFmUlyad">volcanic glass</a>, produced during <a href="/facts/Volcano/c2M5upml">volcanic</a> <a href="/facts/Eruptions/AwqpzdaG">eruptions</a> and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to refer to all <a href="/facts/Explosive_eruption/NkCmmgQG">explosive eruption</a> products (correctly referred to as <a href="/facts/Tephra/fYHmdLu1">tephra</a>), including particles larger than 2 mm. Volcanic ash is formed during explosive volcanic eruptions when dissolved gases in <a href="/facts/Magma/hRotHju9">magma</a> expand and escape violently into the atmosphere. The force of the gases shatters the magma and propels it into the atmosphere where it solidifies into fragments of volcanic rock and glass. Ash is also produced when magma comes into contact with water during <a href="/facts/Phreatomagmatic_eruption/xyVrc386">phreatomagmatic eruptions</a>, causing the water to explosively flash to steam leading to shattering of magma. Once in the air, ash is transported by wind up to thousands of kilometres away.
Due to its wide dispersal, ash can have a number of impacts on society, including animal and human health problems, disruption to aviation, disruption to critical infrastructure (e.g., electric power supply systems, telecommunications, water and waste-water networks, transportation), primary industries (e.g., agriculture), and damage to buildings and other structures.

Volcanic ash open-in-new

Volcanic ash