Volcanic ash is the term for very fine rock and mineral particles less than 2 mm in diameter that are ejected from a volcanic vent. Ash is created when solid rock shatters and magma separates into minute particles during explosive volcanic activity. The usually violent nature of an eruption involving steam (phreatic eruption) results in the magma and perhaps solid rock surrounding the vent, being torn into particles of clay to sand size. The plume that is often seen above an erupting volcano is composed primarily of ash and ste ...

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Volcanic ash - Characteristics Volcanic ash - Dangers Volcanic ash - Ash and aviation Volcanic ash - Atmospheric effects

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Volcanic ash, Volcanic ash - Characteristics, Volcanic ash - Dangers, Volcanic ash - Ash and aviation, Volcanic ash - Atmospheric effects

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Volcanic ash jams machinery. This poses a great danger to aircraft flying near ash clouds. There are many instances of damage to jet aircraft as a result of an ash encounter. Engines may quit, and fuel and water systems may become fouled, requiring repair. After the Galunggung, Indonesia volcanic event in 1982, a British Airways Boeing 747 flew through an ash cloud that fouled all 4 engines, stopping them. The plane descended from 36,000 feet to only 12,000 feet bef ...

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Volcanic ash, Volcanic ash - Characteristics, Volcanic ash - Dangers, Volcanic ash - Ash and aviation, Volcanic ash - Atmospheric effects

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Volcanic cones are among the simplest volcano formations. They are built by fragments (called ejecta) thrown up (ejected) from a volcanic vent, piling up around the vent in the shape of a cone with a central crater. Volcanic cones are of different types, depending upon the nature and size of the fragments ejected during the eruption. Types typically differentiated are spatter cone, cinder cone, ash cone, and tuff cone.

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Volcanic cone - Spatter Cone Volcanic cone - Ash Cone Volcanic cone - Cinder Cone

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A volcanic winter is the reduction in temperature caused by volcanic ash and droplets of sulfuric acid obscuring the sun, usually after a volcanic eruption. Volcanic winter - Effects on life. The causes of the bottleneck phenomenon, i.e. a sharp decrease in a species' population immediately followed by a period of great genetic divergence (differentiation) among survivors - might be attributed to volcanic winters. According to anthropologist Stanley Ambrose, such events diminish the population size to "leve ...

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Volcanic winter - Effects on life Volcanic winter - Ancient case of volcanic winters Volcanic winter - Recent cases of volcanic winter

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Bentonite is an absorbent aluminium phyllosilicate generally impure clay consisting mostly of montmorillonite, (Na,Ca)0.33(Al,Mg)2Si4O10(OH)2·nH2O. Two types exist: swelling bentonite which is also called sodium bentonite and non-swelling bentonite or calcium bentonite. It forms from weathering of volcanic ash, most often in the presence of water. Bentonite expands when wet - sodium bentonite can absorb several hundred percent of its dry wei ...

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Montmorillonite is a very soft phyllosilicate mineral that typically forms in microscopic crystals, forming a clay. Montmorillonite, a member of the smectite family, is a 2:1 clay, meaning that it has 2 tetrahedral sheets sandwiching a central octahedral sheet. The particles are plate-shaped with an average diameter of approximately 1 micrometre. The particle thickness is extremely small (~ 1 nm). It is the main constituent of the volcanic ash weathering product, bentonite. Montmorillonite's water content is variable and it inc ...

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Montmorillonite - Reference

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Blue Amber is a rare coloration of amber. It most commonly is found in the Dominican Republic and well regarded by collectors for its value. Blue Amber - Origin. It is not fully understood what causes the blue coloration. One theory links the rare properties to the occurrence of volcanic ash or dust which was present when the resin was first pressed out from Hymenaea protera millions of years ago. Another suggests that due to volcanic activity hot lava must have flown over those areas where regular a ...

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Blue Amber - Origin Blue Amber - Is it really blue?

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August 24 is the 236th day of the year in the Gregorian Calendar (237th in leap years), with 129 days remaining. August 24 - Events. 49 BC - Julius Caesar's general Gaius Curio is defeated in the Second Battle of the Bagradas River by the Numidians under Attius Varus and King Juba of Numidia. Curio is slain in battle. AD 79 - Mount Vesuvius erupts. The cities of Pompeii, Herculaneum, and Stabiae are buried in volcanic ash. 410 - The Visigoths under Alar ...

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August 24 - Events August 24 - Births August 24 - Deaths August 24 - Holidays and observances

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Assyrtiko or Asyrtiko is the indigenous white wine grape of the island of Santorini, Greece. Considered Greece's best white grape varietal by experts such as Nico Manessis, author of The Greek Wine Guide (Olive), assyrtiko is widely planted in the arid volcanic-ash-rich soil of Santorini and other Aegean islands, mainly on Paros (as well as in other scattered regions of Greece like Chalkidiki for example), where the average age of the root stock is 70 years, and many vines date back 150 years or more. The grapes are large and round, and have a ...

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Assyrtiko - External link

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 Chinchilla  Lagidium  Lagostomus Chinchillas and their relatives viscachas are small, nocturnal mammals native to the Andes mountains in South America and belonging to the family Chinchillidae. Chinchilla fur is considered the softest in the world and is thirty times softer than human hair. Chinchillas must regularly bathe in dust or volcanic ash to remove oil and moisture that gathers in their thick fur. In fact, they have the highest fur density o ...

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Chinchilla - Chinchillas as Pets Chinchilla - Classification

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A weather satellite is a type of artificial satellite that is primarily used to monitor the weather and climate of the Earth. These meteorological satellites, however, see more than clouds and cloud systems. City lights, fires, pollution, auroras, sand and dust storms, snow cover, ice mapping, ocean currents, energy waste, etc., are other environmental information collected from weather satellites. Weather satellite images helped in monitoring the volcanic ash cloud from Mount St. Helens and activity from other volcanoes such as Mount Etna. Smoke from fires in the western United St ...

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Weather satellite - History Weather satellite - Types Weather satellite - External link

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Aden (Arabic: عدن [ʿAdan]) is a city in Yemen, 105 miles (170 kilometers) East of Bab-el-Mandeb. It is a natural port, built on an old volcanic peninsula and first used by the ancient Kingdom of Awsan between the 5th and 7th centuries BC. Aden has a population of about 590,000[1] and is located at 12.779444° N 45.03667° E. Aden consists of a number of small towns: the port city, the industrial city known as Little Aden with its large oil refinery, and Madinat ash-Sha'b, ...

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Aden - History
Aden - British Rule Aden - Little Aden 1955 to 1967 Aden - Federation of South Arabia and the Aden Emergency Aden - Independence

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Among the loose beds of ash that cover the slopes of many volcanoes, three classes of materials are represented. In addition to true ashes of the kind described above, there are lumps of the old lavas and tuffs forming the walls of the crater, etc., which have been torn away by the violent outbursts of steam, and pieces of sedimentary rocks from the deeper parts of the volcano that were dislodged by the rising lava and are often intensely baked and recrystallized by the heat t ...

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Tuff, Tuff - Volcanic ash, Tuff - Breccias, Tuff - Igneous rock, Tuff - Welded Tuff, Tuff - Rhyolite tuffs, Tuff - Trachyte tuffs, Tuff - Andesitic tuffs, Tuff - Basaltic tuffs, Tuff - Ultra-basic tuffs, Tuff - Folding and metamorphosis, Tuff - Economic importance

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1980 eruption of Mount St. Helens - Initial lateral blast. The landslide suddenly exposed the dacite magma in St. Helens' neck to much lower pressure, causing the gas-charged, partially molten rock and high-pressure steam above it to explode a few seconds after the slide started. Explosions burst through the trailing part of the landslide, blasting rock debris northward. The resulting laterally directed pyroclastic flow of super-heated volcanic gases, ash and pumice from new lava, and pulverized old rock hugged t ...

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1980 eruption of Mount St. Helens, 1980 eruption of Mount St. Helens - Buildup to disaster, 1980 eruption of Mount St. Helens - North face slides away, 1980 eruption of Mount St. Helens - Pyroclastic flows, 1980 eruption of Mount St. Helens - Initial lateral blast, 1980 eruption of Mount St. Helens - Lateral blast result, 1980 eruption of Mount St. Helens - Later flows, 1980 eruption of Mount St. Helens - Ash column grows, 1980 eruption of Mount St. Helens - Mudslides flow downstream, 1980 eruption of Mount St. Helens - Aftermath, 1980 eruption of Mount St. Helens - Direct results, 1980 eruption of Mount St. Helens - Digging out, 1980 eruption of Mount St. Helens - Cost, 1980 eruption of Mount St. Helens - Later eruptions

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The hot, exploding material also broke apart and melted nearly all of the mountain's glaciers along with most of the overlying snow. As in many previous St. Helens' eruptions, this created huge lahars (volcanic mudflows) and muddy floods that affected 3 of the 4 stream drainage systems on the mountain and which started to move as early as 8:50 AM. Lahars traveled as fast as 90 mph (145 km/h) while still high on the volcano but progressively slowed to about 3 mph (5 km/h) on the flatter and wider parts of rivers. Mudflows off t ...

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1980 eruption of Mount St. Helens, 1980 eruption of Mount St. Helens - Buildup to disaster, 1980 eruption of Mount St. Helens - North face slides away, 1980 eruption of Mount St. Helens - Pyroclastic flows, 1980 eruption of Mount St. Helens - Initial lateral blast, 1980 eruption of Mount St. Helens - Lateral blast result, 1980 eruption of Mount St. Helens - Later flows, 1980 eruption of Mount St. Helens - Ash column grows, 1980 eruption of Mount St. Helens - Mudslides flow downstream, 1980 eruption of Mount St. Helens - Aftermath, 1980 eruption of Mount St. Helens - Direct results, 1980 eruption of Mount St. Helens - Digging out, 1980 eruption of Mount St. Helens - Cost, 1980 eruption of Mount St. Helens - Later eruptions

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1980 eruption of Mount St. Helens - Direct results. The May 18, 1980, event was the most deadly and economically destructive volcanic eruption in the history of the United States. Fifty-seven people were killed and 200 homes, 47 bridges, 15 miles (24 km) of railways and 185 miles (300 km) of highway were destroyed. U.S. President Jimmy Carter surveyed the damage and stated it looked more desolate than a moonscape. A film crew was dropped by helicopter on St. Helens on May 23 to document the destruction. Their com ...

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1980 eruption of Mount St. Helens, 1980 eruption of Mount St. Helens - Buildup to disaster, 1980 eruption of Mount St. Helens - North face slides away, 1980 eruption of Mount St. Helens - Pyroclastic flows, 1980 eruption of Mount St. Helens - Initial lateral blast, 1980 eruption of Mount St. Helens - Lateral blast result, 1980 eruption of Mount St. Helens - Later flows, 1980 eruption of Mount St. Helens - Ash column grows, 1980 eruption of Mount St. Helens - Mudslides flow downstream, 1980 eruption of Mount St. Helens - Aftermath, 1980 eruption of Mount St. Helens - Direct results, 1980 eruption of Mount St. Helens - Digging out, 1980 eruption of Mount St. Helens - Cost, 1980 eruption of Mount St. Helens - Later eruptions

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Several small earthquakes beginning as early as March 16, 1980, indicated that magma may have been moving below the volcano. Then on March 20 at 3:47 PM Pacific Standard Time (all times will be in PST), a shallow Richter magnitude 4.2 earthquake, centered below the mountain's north flank, definitely signaled the volcano's violent return from 123 years of hibernation. A gradually building earthquake swarm saturated area seismographs and started to climax at about noon on March 25, reaching peak levels in the next two days (a to ...

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1980 eruption of Mount St. Helens, 1980 eruption of Mount St. Helens - Buildup to disaster, 1980 eruption of Mount St. Helens - North face slides away, 1980 eruption of Mount St. Helens - Pyroclastic flows, 1980 eruption of Mount St. Helens - Initial lateral blast, 1980 eruption of Mount St. Helens - Lateral blast result, 1980 eruption of Mount St. Helens - Later flows, 1980 eruption of Mount St. Helens - Ash column grows, 1980 eruption of Mount St. Helens - Mudslides flow downstream, 1980 eruption of Mount St. Helens - Aftermath, 1980 eruption of Mount St. Helens - Direct results, 1980 eruption of Mount St. Helens - Digging out, 1980 eruption of Mount St. Helens - Cost, 1980 eruption of Mount St. Helens - Later eruptions

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During the last 10,000 years Shasta has erupted an average of every 800 years but in the past 4500 years the volcano has erupted an average of every 600 years. The last significant eruption on Shasta may have occurred 200 years ago. Mount Shasta can release volcanic ash, pyroclastic flows or dacite and andesite lava. Its deposits can be detected under two nearby small towns totalling 20,000 in population. Shasta has an explosive, eruptive history. There are fumaroles on the ...

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Mount Shasta, Mount Shasta - Geology, Mount Shasta - Volcanic hazards, Mount Shasta - Religion, Mount Shasta - Cultural References

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At 7 AM on May 18, USGS volcanologist David A. Johnston, who had Saturday night duty at an observation post about 6 miles (10 km) north of the mountain, radioed in the results of some laser-beam measurements he had made moments earlier. Mount St. Helens' activity that day did not show any change from the pattern of the preceding month. The rate of bulge movement, sulfur-dioxide gas emission, and ground temperature readings did ...

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1980 eruption of Mount St. Helens, 1980 eruption of Mount St. Helens - Buildup to disaster, 1980 eruption of Mount St. Helens - North face slides away, 1980 eruption of Mount St. Helens - Pyroclastic flows, 1980 eruption of Mount St. Helens - Initial lateral blast, 1980 eruption of Mount St. Helens - Lateral blast result, 1980 eruption of Mount St. Helens - Later flows, 1980 eruption of Mount St. Helens - Ash column grows, 1980 eruption of Mount St. Helens - Mudslides flow downstream, 1980 eruption of Mount St. Helens - Aftermath, 1980 eruption of Mount St. Helens - Direct results, 1980 eruption of Mount St. Helens - Digging out, 1980 eruption of Mount St. Helens - Cost, 1980 eruption of Mount St. Helens - Later eruptions

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