Related topics: volcano

Looking back at the 2022 eruption that shook the world

One year ago, the Hunga Tonga-Hunga Ha'apai volcano erupted, causing widespread destruction to the Pacific Island Nation of Tonga, spewing volcanic material up to 58 km into the atmosphere. It brought a nearly 15 m tsunami ...

Lascar volcano in Chile stirs, sending plume skyward

A volcano in the Andes in Chile's north rumbled to life early Saturday, triggering minor earth tremors and sending a plume of smoke and ash 6,000 meters (nearly 20,000 feet) into a clear sky.

The geologic secrets of Lake Mead

As the climate crisis continues to affect the American West, sunken boats and human remains aren't the only surprises to be revealed by record-low water levels at Lake Mead. Sedimentary rocks that hadn't been seen since the ...

Explosive volcanic eruption produced rare mineral on Mars

Planetary scientists from Rice University, NASA's Johnson Space Center and the California Institute of Technology have an answer to a mystery that's puzzled the Mars research community since NASA's Curiosity rover discovered ...

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Volcanic ash

Volcanic ash consists of small tephra, which are bits of pulverized rock and glass created by volcanic eruptions, less than 2 millimetres (0.079 in) in diameter. There are three mechanisms of volcanic ash formation: gas release under decompression causing magmatic eruptions; thermal contraction from chilling on contact with water causing phreatomagmatic eruptions and ejection of entrained particles during steam eruptions causing phreatic eruptions. The violent nature of volcanic eruptions involving steam results in the magma and solid rock surrounding the vent being torn into particles of clay to sand size. Volcanic ash can lead to breathing problems, malfunctions in machinery, and from more severe eruptions, years of global cooling.

Ash deposited on the ground after an eruption is known as ashfall deposit. Significant accumulations of ashfall can lead to the immediate destruction of most of the local ecosystem, as well the collapse of roofs on man-made structures. Over time, ashfall can lead to the creation of fertile soils. Ashfall can also become cemented together to form a solid rock called tuff. Over geologic time, the ejection of large quantities of ash can produce an ash cone.

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