Encyclopedia - Volcanic Ash: Encyclopedia - Volcanic Ash
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 i...   » Read the article

Encyclopedia - Volcanic Ash: Encyclopedia Ii - Volcanic Ash - Dangers
Volcanic ash is not poisonous, but inhaling it may cause problems for people whose respiratory system is already compromised by disorders...   » Read the article

Encyclopedia - Volcanic Ash: Encyclopedia Ii - Volcanic Ash - Ash And Aviation
Volcanic ash jams machinery. This poses a great danger to aircraft flying near ash clouds. There are many instances of damage to jet airc...   » Read the article

Encyclopedia - Volcanic Cone: Encyclopedia - Volcanic Cone
Volcanic cones are among the simplest volcano formations. They are built by fragments (called ejecta) thrown up (ejected) from a volcanic...   » Read the article

Encyclopedia - Volcanic Winter: Encyclopedia - Volcanic Winter
A volcanic winter is the reduction in temperature caused by volcanic ash and droplets of sulfuric acid obscuring the sun, usually after a...   » Read the article

Encyclopedia - Bentonite: Encyclopedia - Bentonite
Bentonite is an absorbent aluminium phyllosilicate generally impure clay consisting mostly of montmorillonite, (Na,Ca)0.33(Al,Mg)2Si4O10(...   » Read the article

Encyclopedia - Montmorillonite: Encyclopedia - Montmorillonite
Montmorillonite is a very soft phyllosilicate mineral that typically forms in microscopic crystals, forming a clay. Montmorillonite, a me...   » Read the article

Encyclopedia - Blue Amber: Encyclopedia - Blue Amber
Blue Amber is a rare coloration of amber. It most commonly is found in the Dominican Republic and well regarded by collectors for its val...   » Read the article

Encyclopedia - August 24: Encyclopedia - August 24
August 24 is the 236th day of the year in the Gregorian Calendar (237th in leap years), with 129 days remaining. August 24 - Events. 4...   » Read the article

Encyclopedia - Assyrtiko: Encyclopedia - Assyrtiko
Assyrtiko or Asyrtiko is the indigenous white wine grape of the island of Santorini, Greece. Considered Greece's best white grape varieta...   » Read the article

Encyclopedia - Chinchilla: Encyclopedia - Chinchilla
 Chinchilla  Lagidium  Lagostomus Chinchillas and their relatives viscachas are small, nocturnal mammals native to the And...   » Read the article

Encyclopedia - Weather Satellite: Encyclopedia - Weather Satellite
A weather satellite is a type of artificial satellite that is primarily used to monitor the weather and climate of the Earth. These meteo...   » Read the article

Encyclopedia - Aden: Encyclopedia - Aden
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 o...   » Read the article

Encyclopedia - Tuff: Encyclopedia Ii - Tuff - Breccias
Among the loose beds of ash that cover the slopes of many volcanoes, three classes of materials are represented. In addition to true ashe...   » Read the article

Encyclopedia - 1980 Eruption Of Mount St. Helens: Encyclopedia Ii - 1980 Eruption Of Mount St. Helens - Pyroclastic Flows
1980 eruption of Mount St. Helens - Initial lateral blast. The landslide suddenly exposed the dacite magma in St. Helens' neck to much ...   » Read the article

Encyclopedia - 1980 Eruption Of Mount St. Helens: Encyclopedia Ii - 1980 Eruption Of Mount St. Helens - Mudslides Flow Downstream
The hot, exploding material also broke apart and melted nearly all of the mountain's glaciers along with most of the overlying snow. As i...   » Read the article

Encyclopedia - 1980 Eruption Of Mount St. Helens: Encyclopedia Ii - 1980 Eruption Of Mount St. Helens - Aftermath
1980 eruption of Mount St. Helens - Direct results. The May 18, 1980, event was the most deadly and economically destructive volcanic e...   » Read the article

Encyclopedia - 1980 Eruption Of Mount St. Helens: Encyclopedia Ii - 1980 Eruption Of Mount St. Helens - Buildup To Disaster
Several small earthquakes beginning as early as March 16, 1980, indicated that magma may have been moving below the volcano. Then on Marc...   » Read the article

Encyclopedia - Mount Shasta: Encyclopedia Ii - Mount Shasta - Volcanic Hazards
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 avera...   » Read the article

Encyclopedia - 1980 Eruption Of Mount St. Helens: Encyclopedia Ii - 1980 Eruption Of Mount St. Helens - North Face Slides Away
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 o...   » Read the article

Encyclopedia - Lake Toba: Encyclopedia Ii - Lake Toba - Geology
In 1949 the Dutch geologist Rein van Bemmelen reported that Lake Toba was surrounded by a layer of ignimbrite rocks, and was a large volc...   » Read the article

Encyclopedia - 1980 Eruption Of Mount St. Helens: Encyclopedia Ii - 1980 Eruption Of Mount St. Helens - Ash Column Grows
As the avalanche and initial pyroclastic flow were still advancing, a huge ash column grew to a height of 12 miles (19 km) above the expa...   » Read the article

Encyclopedia - Blue Amber: Encyclopedia Ii - 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 dus...   » Read the article

Encyclopedia - 1980 Eruption Of Mount St. Helens: Encyclopedia Ii - 1980 Eruption Of Mount St. Helens - Later Eruptions
St. Helens produced five more explosive eruptions in the summer and fall of 1980. Through early 1990, a total of at least 21 periods of e...   » Read the article

Encyclopedia - Geology Of The Lassen Area: Encyclopedia Ii - Geology Of The Lassen Area - Volcanoes Rise
Pyroclastic eruptions then started to pile tephra into cones in the northern area of the park. Mount Tehama (also known as Brokeoff Volca...   » Read the article

Encyclopedia - Feathered Dinosaurs: Encyclopedia Ii - Feathered Dinosaurs - Fossil Evidence
After a century of hypotheses without hard evidence, beautifully preserved - and legitimate - fossils of feathered dinosaurs were discove...   » Read the article

Encyclopedia - Santorini: Encyclopedia Ii - Santorini - Minoan Akrotiri
Excavations starting in 1967 at the site called Akrotiri under the late Prof. Spyridon Marinatos have made Thera the best-known "Minoan" ...   » Read the article

Encyclopedia - Supervolcano: Encyclopedia Ii - Supervolcano - Massive Eruptions
Eruptions with a Volcanic Explosivity Index of 8 (VEI-8) are mega-colossal events that extrude at least 1000 km³ of magma and pyroclasti...   » Read the article

Encyclopedia - Louis Leakey: Encyclopedia Ii - Louis Leakey - Prominent Family Members
Louis Leakey was married to Mary Leakey, who made perhaps the most important discovery in Palaeolithic archeology, the Laetoli footprints...   » Read the article

Encyclopedia - Calistoga California: Encyclopedia Ii - Calistoga California - Tourist Attractions
Calistoga is at the north end of the Napa Valley, heart of California's famous wine country. Thus there are many wineries within a short ...   » Read the article

Encyclopedia - Ray System: Encyclopedia Ii - Ray System - Lunar Rays
The physical nature of lunar rays has historically been a subject of speculation. Early hypotheses suggested that they were deposits of s...   » Read the article

Encyclopedia - Impact Winter: Encyclopedia Ii - Impact Winter - Impact Winters In Popular Culture
Impact winter (along with nuclear and volcanic winters) are often the subject of science fiction novels and short stories. In the episode...   » Read the article

Encyclopedia - Lago De Atitlán: Encyclopedia Ii - Lago De Atitlán - Geological History
The region first saw volcanic activity about 11 million years ago, and since then has seen four separate episodes of volcanic growth and ...   » Read the article

Encyclopedia - Battle Of Iwo Jima: Encyclopedia Ii - Battle Of Iwo Jima - D-day
At 02:00 on February 19, battleship guns signaled the commencement of D-Day. Soon 100 bombers attacked the island, followed by another vo...   » Read the article

Encyclopedia - Pompeii: Encyclopedia Ii - Pompeii - Lost For 16 Centuries
Thick layers of ash covered two towns located at the base of the mountain, and eventually their names and locations were forgotten. Then ...   » Read the article

Encyclopedia - Golemon: Encyclopedia Ii - Golemon - Abilities
The spell that brought it to life, "yaku" "juu" "kyou" (epidemic, curse, evil), is carved on its back. This incantation, by fending for i...   » Read the article

Encyclopedia - Pilot Reports: Encyclopedia Ii - Pilot Reports - Soliciting Pireps
In the US, Air Traffic Controllers are required to solicit PIREPs upon request of other facilities or pilots, or when any of the followin...   » Read the article

Encyclopedia - Ice Core: Encyclopedia Ii - Ice Core - Ice Core Data
Many materials can appear in an ice core. Layers can be measured in several ways to identify changes in composition. Small meteorites may...   » Read the article

Encyclopedia - Quito: Encyclopedia Ii - Quito - Geography
Quito is located in the northern sierra of Ecuador in the Guayllabamba river basin. The eastern part of the basin is sorrounded by a numb...   » Read the article

Encyclopedia - Cambrian: Encyclopedia - Cambrian
The Cambrian is a major division of the geologic timescale that begins about 542 Ma (million years ago) at the end of the Proterozoic eon...   » Read the article

Encyclopedia - Caldera: Encyclopedia - Caldera
A caldera is a volcanic feature formed by the collapse of a volcano into itself. Calderas may be filled with water, creating crater lakes...   » Read the article

Encyclopedia - Yellowstone Caldera: Encyclopedia - Yellowstone Caldera
The Yellowstone Caldera, also known as the Yellowstone supervolcano, is a volcanically active region in Yellowstone National Park. It mea...   » Read the article

Encyclopedia - Air Safety: Encyclopedia - Air Safety
Air safety - Certification. In most countries, civil aircraft have to be certified by the civil aviation authority (CAA) to be allowed ...   » Read the article

Encyclopedia - Aegean Civilization: Encyclopedia - Aegean Civilization
Aegean civilization is the general term for the prehistoric civilizations in Greece and the Aegean. It was formerly called "Mycenaean" be...   » Read the article

Encyclopedia - Lava: Encyclopedia - Lava
Lava is molten rock that a volcano expels during an eruption. Lava, when first exuded from a volcanic vent, is a liquid at very high temp...   » Read the article

Encyclopedia - Volcano: Encyclopedia - Volcano
A volcano is a geological landform (usually a mountain) where a substance, usually magma (rock of the Earth's interior made molten or liq...   » Read the article

Encyclopedia - Flood: Encyclopedia - Flood
A flood (in Old English flod, a word common to Teutonic languages; compare German Flut, Dutch vloed from the same root as is seen in flow...   » Read the article

Encyclopedia - Walking With Dinosaurs: Encyclopedia - Walking With Dinosaurs
Walking with Dinosaurs is a 1999 six-part television series produced by the BBC and narrated by Kenneth Branagh (UK version, BBC) and Ave...   » Read the article

Encyclopedia - Ignimbrite: Encyclopedia Ii - Ignimbrite - Occurrence
Ignimbrites occur worldwide associated with any volcanic province with high-silica content magma and the resulting explosive eruptions. I...   » Read the article

Encyclopedia - Glacier Peak: Encyclopedia Ii - Glacier Peak - Eruptive History
Glacier Peak is actually a small stratovolcano despite its elevation of 10,541 feet (3213 meters); it is perched atop a ridge and the vol...   » Read the article

Encyclopedia - Lava: Encyclopedia Ii - Lava - Lava Composition And Rheology
Igneous rocks, which form lava flows when erupted, can be classified into three chemical types; felsic, intermediate and mafic. These cla...   » Read the article

Encyclopedia - Santorini: Encyclopedia Ii - Santorini - Ancient Volcanic Eruption
The devastating volcanic eruption of Thira has become the most famous single event in the Aegean before the fall of Troy. The eruption wo...   » Read the article

Encyclopedia - Mount Shasta: Encyclopedia Ii - Mount Shasta - Geology
Main article: Geology of Mount Shasta The mountain consists of four separate cones buried atop one another. Shastina 12,300 ft (3,749 m) ...   » Read the article

Encyclopedia - Geology Of The Zion And Kolob Canyons Area: Encyclopedia Ii - Geology Of The Zion And Kolob Canyons Area - Deposition Of Sediments
Geology of the Zion and Kolob canyons area - Kaibab Formation Upper Permian. In later Permian time, the Toroweap basin (see above) was ...   » Read the article

Encyclopedia - Geology Of The Capitol Reef Area: Encyclopedia Ii - Geology Of The Capitol Reef Area - Jurassic Events
Geology of the Capitol Reef area - Glen Canyon Group. All three formations of the Glen Canyon Group were laid down in the Mid to Late T...   » Read the article

Encyclopedia - Maya Women: Encyclopedia Ii - Maya Women - Gender Roles
Women did have specific roles that were different than those of men. But, perhaps one of the most prolific ways that women’s roles are ...   » Read the article

Encyclopedia - Yellowstone Caldera: Encyclopedia Ii - Yellowstone Caldera - Volcanism
Yellowstone is on top of one of the planet's few dozen hot spots where light, hot, molten, mantle rock rises towards the surface. Hawaii ...   » Read the article

Encyclopedia - Air Safety: Encyclopedia Ii - Air Safety - Air Safety Topics
Air safety - Dangers. While aircraft are able to withstand normal lightning strikes, the dangers of more powerful positive lightning w...   » Read the article

Encyclopedia - Capitol Reef National Park: Encyclopedia Ii - Capitol Reef National Park - History
Capitol Reef National Park - Native Americans and Mormons. Fremont culture Native Americans lived near the perennial Fremont River in t...   » Read the article

Encyclopedia - Volcanic Winter: Encyclopedia Ii - Volcanic Winter - Ancient Case Of Volcanic Winters
A terrific case of volcanic winter happened around 71,000-73,000 years ago following the super-eruption of Lake Toba on Sumatra island (I...   » Read the article

Encyclopedia - Caldera: Encyclopedia Ii - Caldera - Caldera Formation
A caldera collapse is usually triggered by the emptying of the magma chamber beneath the volcano, often as the result of a large eruption...   » Read the article

Encyclopedia - Volcano: Encyclopedia Ii - Volcano - Volcanology
Volcano - Volcano formation. Like most of the interior of the earth, the movements and dynamics of magma are poorly understood. However...   » Read the article

Encyclopedia - Flood: Encyclopedia Ii - Flood - Main Causes
A flood occurs when an area of land, usually low-lying, is covered with water. The worst floods usually occur when a river overflows its ...   » Read the article

Encyclopedia - Cambrian: Encyclopedia Ii - Cambrian - Cambrian Subdivisions
The Cambrian period follows after the Neoproterozoic and is followed by the Ordovician period. The Cambrian is divided into three epochs ...   » Read the article

Encyclopedia - Air Safety: Encyclopedia Ii - Air Safety - Air Safety Topics
Air safety - Dangers. While aircraft are able to withstand normal lightning strikes, the dangers of more powerful positive lightning w...   » Read the article

Encyclopedia - Lava: Encyclopedia Ii - Lava - Lava Compositions
All volcanic rock (and thus, all lavas and magmas) may be characterized by its relative proportions of three important elements: silica, ...   » Read the article

Encyclopedia - Igneous Rock: Encyclopedia Ii - Igneous Rock - Magma Origination
The Earth's crust is about 35 kilometers thick under the continents, but averages only some 7-10 kilometers beneath the oceans. The conti...   » Read the article

Encyclopedia - Aegean Civilization: Encyclopedia Ii - Aegean Civilization - History Of Aegean Civilization
In the absence of written records, only a summary history can be derived from monuments and archaeological remains. But the decipherment ...   » Read the article

Encyclopedia - Geochronology: Encyclopedia Ii - Geochronology - Radiometric Dating
By measuring the amount of radiocative decay of a radioactive isotope with a known half-life, geologists can establish the absolute age o...   » Read the article

Encyclopedia - Flood: Encyclopedia Ii - Flood - Flood Defenses, Planning, And Management
In western countries, rivers prone to flooding are often carefully managed. Defences such as levees, bunds, reservoirs, and weirs are use...   » Read the article

Encyclopedia - Geology Of The Capitol Reef Area: Encyclopedia Ii - Geology Of The Capitol Reef Area - Cretaceous Events
Geology of the Capitol Reef area - Cedar Mountain and Dakota Sandstone. Early Cretaceous time brought continental deposition that was d...   » Read the article

Encyclopedia - Geology Of The Capitol Reef Area: Encyclopedia Ii - Geology Of The Capitol Reef Area - Triassic Events
Geology of the Capitol Reef area - Moenkopi Formation. Local climatic conditions were wetter and more tropical in the Early Triassic th...   » Read the article

Encyclopedia - Geology Of The Capitol Reef Area: Encyclopedia Ii - Geology Of The Capitol Reef Area - Permian Events
Geology of the Capitol Reef area - Cutler Group. In early Permian time Utah was on a continental shelf that was occasionally covered by...   » Read the article

Encyclopedia - Capitol Reef National Park: Encyclopedia Ii - Capitol Reef National Park - Geology
The area including the park was once the edge of an ancient shallow sea that invaded the land in the Permian, creating the Cutler Formati...   » Read the article

Encyclopedia - Aegean Civilization: Encyclopedia Ii - Aegean Civilization - Distinctive Features
The uniqueness of Aegean civilization has never been in doubt, since its remains came to be studied seriously. For a time the surviving r...   » Read the article

Encyclopedia - Lava: Encyclopedia Ii - Lava - Composition Of Volcanic Rocks
The sub-family of rocks which form from volcanic lava are called Igneous Volcanic rocks (to differentiate them from igneous rocks which f...   » Read the article

Encyclopedia - Ignimbrite: Encyclopedia Ii - Ignimbrite - Use
The layering of ignimbrites is utilized when the stone is worked, as it sometimes splits into convenient slabs, useful for flagstones and...   » Read the article

Encyclopedia - Lava: Encyclopedia Ii - Lava - Lava Formations
Even the most fluid lavas are much more viscous than water, so they tend not to flow as rapidly. Nevertheless, where the slope of the gro...   » Read the article

Encyclopedia - Lava: Encyclopedia Ii - Lava - Lava Formations
Even the most fluid lavas are much more viscous than water, so they tend not to flow as rapidly. Nevertheless, where the slope of the gro...   » Read the article

Encyclopedia - Geology Of The Zion And Kolob Canyons Area: Encyclopedia Ii - Geology Of The Zion And Kolob Canyons Area - Tectonic Activity And Canyon Formation
Geology of the Zion and Kolob canyons area - Regional forces. Compression from subduction off the west coast affected the area to some ...   » Read the article

Encyclopedia - Geology Of The Zion And Kolob Canyons Area: Encyclopedia Ii - Geology Of The Zion And Kolob Canyons Area - The Grand Staircase And Basement Rocks
The oldest exposed formation in the park is the youngest exposed formation in the Grand Canyon—the approximately 240-million-year-old K...   » Read the article

Encyclopedia - Capitol Reef National Park: Encyclopedia Ii - Capitol Reef National Park - Geography
Capitol Reef encompasses the Waterpocket Fold, a wrinkle in the earth's crust that is 65 million years old. In this fold, newer and older...   » Read the article

Encyclopedia - Geology Of The Lassen Area: Encyclopedia Ii - Geology Of The Lassen Area - Formation Of Basement Rocks
In the Cenozoic, uplifting and westward tilting of the Sierra Nevada along with extensive volcanism generated huge lahars (volcanic-deriv...   » Read the article

Encyclopedia - Supervolcano: Encyclopedia Ii - Supervolcano - Large Igneous Provinces
Large igneous provinces are remains of mega-colossal flood basalts that extruded enormous quantities of basaltic lava flat and deep over ...   » Read the article

Encyclopedia - Volcano: Encyclopedia Ii - Volcano - Effects Of Volcanoes
There are many different kinds of volcanic activity and eruptions: phreatic eruptions (steam) explosive eruption of high-silica lava (e....   » Read the article

Encyclopedia - Volcano: Encyclopedia Ii - Volcano - Notable Volcanoes
Volcano - Volcanoes on Earth. Main article: List of volcanoes Mount Baker (Washington, USA) Cold Bay Volcano (Alaska, USA) El Chicho...   » Read the article

Encyclopedia - Volcano: Encyclopedia Ii - Volcano - Volcano Classification
Volcano - Erupted material. One way of classifying volcanoes is by the type of material erupted, which affects the shape of the volcano...   » Read the article

Encyclopedia - Volcano: Encyclopedia Ii - Volcano - Past Beliefs
Before it was understood that most of the Earth's interior is molten, various explanations existed for volcano behavior. For decades afte...   » Read the article

Encyclopedia - Mount Shasta: Encyclopedia Ii - Mount Shasta - Religion
Native American lore of the area held that Shasta is inhabited by the spirit chief Skell who descended from heaven to the mountain's summ...   » Read the article

Encyclopedia - Igneous Rock: Encyclopedia Ii - Igneous Rock - Classification
Igneous rocks are classified according to mode of occurrence, texture, chemical composition, and the geometry of the igneous body. The cl...   » Read the article

Encyclopedia - Igneous Rock: Encyclopedia Ii - Igneous Rock - Mineralogical Classification
For volcanic rocks, mineralogy is important in classifying and naming lavas. The most important criteria is the phenocryst species, follo...   » Read the article

Encyclopedia - Flood: Encyclopedia Ii - Flood - Flood Defenses Planning And Management
In western countries, rivers prone to flooding are often carefully managed. Defences such as levees, bunds, reservoirs, and weirs are use...   » Read the article

Encyclopedia - Caldera: Encyclopedia Ii - Caldera - Notable Calderas
See also Category:Volcanic calderas Africa Ngorongoro Crater (Tanzania, Africa) See Europe for calderas in the Canary Islands Asia A...   » Read the article

Encyclopedia - Air Safety: Encyclopedia Ii - Air Safety - Institutions
Air safety - Certification. In most countries, civil aircraft have to be certified by the civil aviation authority (CAA) to be allowed ...   » Read the article

Encyclopedia - Air Safety: Encyclopedia Ii - Air Safety - Navigation Aids
One of the first navigation aids to be introduced was the introduction of airfield lighting to assist pilots to make landings in poor wea...   » Read the article

Encyclopedia - Igneous Rock: Encyclopedia Ii - Igneous Rock - Morphology And Setting
In terms of modes of occurrence, igneous rocks can be either intrusive (plutonic) or extrusive (volcanic). Igneous rock - Intrusive Igne...   » Read the article

Encyclopedia - Aegean Civilization: Encyclopedia Ii - Aegean Civilization - Evidence Of Aegean Civilization
For details of monumental evidence the articles on Crete, Mycenae, Tiryns, Troad, Cyprus, etc., must be consulted. The most representativ...   » Read the article

Encyclopedia - Aegean Civilization: Encyclopedia Ii - Aegean Civilization - The Discovery Of Aegean Civiliation
The curtain-wall and towers of the Mycenaean citadel, its gate with heraldic lions, and the great "Treasury of Atreus" had borne silent w...   » Read the article

Encyclopedia - Volcanic Winter: Encyclopedia Ii - Volcanic Winter - Recent Cases Of Volcanic Winter
The scales of recent winters are more modest but their effects can be significant. A paper written by Benjamin Franklin in 1783 blamed th...   » Read the article

Encyclopedia - Aegean Civilization: Encyclopedia Ii - Aegean Civilization - Commerce
Commerce was practised to some extent in very early times, as is proved by the distribution of Melian obsidian over all the Aegean area a...   » Read the article