News tagged with volcanic ash
NASA satellite confirms sharp decline in pollution from US coal power plants
A team of scientists have used the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite to confirm major reductions in the levels of a key air pollutant generated by coal power plants in the eastern ...
Dec 01, 2011 |
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Using biochar to boost soil moisture
Scientists at the U.S. Department of Agriculture (USDA) are leading the way in learning more about "biochar," the charred biomass created from wood, other plant material, and manure.
Nov 08, 2011 |
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Iceland's Katla volcano is getting restless
(AP) -- If Iceland's air-traffic paralyzing volcanic eruption last year seemed catastrophic, just wait for the sequel. That's what some experts are saying as they nervously watch rumblings beneath a much ...
Space & Earth / Earth Sciences
Oct 13, 2011 |
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Team discovers ancient road at Maya village buried by volcanic ash 1,400 years ago
A University of Colorado Boulder-led team excavating a Maya village in El Salvador buried by a volcanic eruption 1,400 years ago has unexpectedly hit an ancient white road that appears to lead to and from ...
Other Sciences / Archaeology & Fossils
Oct 05, 2011 |
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Three active volcanoes spotted on satellite imagery from NASA
(PhysOrg.com) -- From space, NASA keeps a watchful eye on volcanic activity around the world with many satellites. NASA has just released satellite images showing activity this week from volcanoes in the countries ...
Space & Earth / Earth Sciences
Jul 11, 2011 |
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Iceland's Hekla volcano shows signs of activity
(AP) -- Scientists are monitoring unusual underground activity that could signal an eruption at the Hekla volcano in southern Iceland.
Space & Earth / Earth Sciences
Jul 06, 2011 |
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Ancient sewer excavation sheds light on the Roman diet
(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 ...
Other Sciences / Archaeology & Fossils
Jun 17, 2011 |
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Chileans living near volcano urged to stay away
(AP) -- Chilean officials ordered most residents already evacuated from homes near an erupting volcano to stay in shelters and with family and friends Sunday due to the threat of deadly landslides. The ash ...
Space & Earth / Earth Sciences
Jun 13, 2011 |
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Chile volcano ash grounds Australia, NZ flights
Ash from Chile's volcanic eruptions prompted Australian airline Qantas to ground some domestic services and some flights to New Zealand on Sunday, after plumes drifted across the Pacific.
Space & Earth / Earth Sciences
Jun 12, 2011 |
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Volcanic ash cloud disrupts South America flights
A vast cloud of ash spewing from a Chilean volcano disrupted air travel across much of South America, while heavy rains around the eruption site prompted fears of mudslides.
Space & Earth / Earth Sciences
Jun 08, 2011 |
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Satellite observations show potential to improve ash cloud forecasts
Predicting the exact dispersal of a volcanic ash cloud is never going to be easy. However, satellite data are showing that the eruption from Iceland's Grímsvötn volcano this week was unlikely to ...
Space & Earth / Earth Sciences
May 27, 2011 |
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Iceland volcano eruption all but over: experts
The eruption of Iceland's Grimsvoetn volcano has tailed off and its ash plume has almost disappeared, experts and officials said on Wednesday, refusing though to declare the flight-disrupting incident closed.
Space & Earth / Earth Sciences
May 25, 2011 |
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Flights grounded as ash cloud reaches Britain
Airlines halted dozens of flights on Tuesday after a plume of ash from an erupting volcano in Iceland blew over Britain, even forcing US President Barack Obama to revise his travel plans.
Space & Earth / Earth Sciences
May 24, 2011 |
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Icelandic volcano flings up ash, shuts airport
(AP) -- Iceland closed its main international airport and canceled all domestic flights Sunday as a powerful volcanic eruption sent a plume of ash, smoke and steam 12 miles (20 kilometers) into the air.
Space & Earth / Earth Sciences
May 22, 2011 |
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Mars Express sees deep fractures on Mars
Newly released images from ESA's Mars Express show Nili Fossae, a system of deep fractures around the giant Isidis impact basin. Some of these incisions into the martian crust are up to 500 m deep and probably ...
Space & Earth / Space Exploration
May 06, 2011 |
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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.
For more information about Volcanic ash, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
