Around A.D. 79, Roman author Pliny the Elder wrote in his Naturalis Historia that concrete structures in harbors, exposed to the constant assault of the saltwater waves, become "a single stone mass, impregnable to the waves ...
Materials Science
Jul 3, 2017
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4481
One of the oldest known Homo sapiens fossils may be more than 35,000 years older than previously thought, according to a study on Wednesday that used volcanic ash to date the find.
Paleontology & Fossils
Jan 15, 2022
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425
Volcanoes are renowned for their destructive power. In fact, there are few forces of nature that rival their sheer, awesome might, or have left as big of impact on the human psyche. Who hasn't heard of tales of Mt. Vesuvius ...
Earth Sciences
Mar 21, 2016
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152
A deadly volcanic eruption near Tonga in January was the largest ever recorded with modern equipment, a New Zealand-led team of scientists revealed Monday.
Earth Sciences
Nov 21, 2022
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287
A badger-like mammal was sinking its teeth into the ribs of a dinosaur three times its size when they were buried in volcanic ash 125 million years ago, capturing the pair in a deadly embrace.
Paleontology & Fossils
Jul 22, 2023
1
186
One of California's riskiest volcanoes has for decades been undergoing geological changes and seismic activity, which are sometimes a precursor to an eruption, but—thankfully—no supervolcanic eruptions are expected.
Earth Sciences
Oct 28, 2023
0
66
In the unlikely event of a volcanic supereruption at Yellowstone National Park, the northern Rocky Mountains would be blanketed in meters of ash, and millimeters would be deposited as far away as New York City, Los Angeles ...
Earth Sciences
Aug 27, 2014
10
0
A new geological record of the Yellowstone supervolcano's last catastrophic eruption is rewriting the story of what happened 630,000 years ago and how it affected Earth's climate. This eruption formed the vast Yellowstone ...
Earth Sciences
Oct 26, 2017
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682
(PhysOrg.com) -- Archaeologists working in a system of connected sewers and drains under the ancient town of Herculaneum in the Bay of Naples area of Italy have analyzed the human excrement found there and discovered the ...
Archaeologists have unearthed the petrified remains of a harnessed horse and saddle in the stable of an ancient villa in a Pompeii suburb.
Archaeology
Dec 23, 2018
0
267
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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