Earth Sciences, VER-XEN

The Earth sciences are the fields of study concerned with the solid Earth, its waters, and the air that envelops it. Included are the geologic, hydrologic, and atmospheric sciences.
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Earth Sciences Encyclopedia Articles By Title

Vertisol
Vertisol, one of the 12 soil orders in the U.S. Soil Taxonomy. Vertisols are clay-rich soils that undergo significant......
Vertisol
Vertisol, one of the 30 soil groups in the classification system of the Food and Agriculture Organization (FAO).......
vesuvianite
vesuvianite, common silicate mineral that occurs in crystalline limestones near their contacts with igneous rocks,......
Vesuvius
Vesuvius, active volcano that rises above the Bay of Naples on the plain of Campania in southern Italy. Its western......
Virgilian series
Virgilian series, major division of Late Carboniferous rocks and time in the United States (the Late Carboniferous......
Viséan Stage
Viséan Stage, second of three internationally defined stages of the Mississippian Subsystem of the Carboniferous......
vivianite
vivianite, phosphate mineral, hydrated iron phosphate [Fe3(PO4)2·8H2O], that occurs as colourless when freshly......
volcanic eruption
volcanic eruption, an eruption of molten rock, hot rock fragments, and hot gases through a volcano, which is a......
volcanic glass
volcanic glass, any glassy rock formed from lava or magma that has a chemical composition close to that of granite......
volcanic winter
volcanic winter, cooling at Earth’s surface resulting from the deposition of massive amounts of volcanic ash and......
volcanism
volcanism, any of various processes and phenomena associated with the surficial discharge of molten rock, pyroclastic......
volcanology
volcanology, discipline of the geologic sciences that is concerned with all aspects of volcanic phenomena. Volcanology......
Waal Interglacial Stage
Waal Interglacial Stage, division of Pleistocene time and deposits in the Netherlands and northern Europe (the......
wacke
wacke, sedimentary rock composed of sand-sized grains (0.063–2 mm [0.0025–0.078 inch]) with a fine-grained clay......
wad
wad, black and earthy substance that consists mainly of hydrated manganese oxides; it is an important ore of manganese.......
wairakite
wairakite, hydrated calcium aluminosilicate mineral present in hot-spring deposits, notably those at Wairakei,......
water cycle
water cycle, cycle that involves the continuous circulation of water in the Earth-atmosphere system. Of the many......
water mass
water mass, body of ocean water with a distinctive narrow range of temperature and salinity and a particular density......
water table
water table, upper level of an underground surface in which the soil or rocks are permanently saturated with water.......
Waterberg Series
Waterberg Series, major division of rocks in southern Africa. The age of the Waterberg is in doubt; it is possible......
waterspout
waterspout, a small-diameter column of rapidly swirling air in contact with a water surface. Waterspouts are almost......
Waucoban Series
Waucoban Series, lowermost Cambrian rocks (the Cambrian Period lasted from 542 million to 488 million years ago);......
wave
wave, a ridge or swell on the surface of a body of water, normally having a forward motion distinct from the oscillatory......
wavellite
wavellite, hydrated aluminum phosphate [Al3(PO4)2(OH)3·5H2O], a common phosphate mineral that typically occurs......
weather
weather, state of the atmosphere at a particular place during a short period of time. It involves such atmospheric......
weather bureau
weather bureau, agency established by many countries to observe and report the weather and to issue weather forecasts......
weather map
weather map, any map or chart that shows the meteorological elements at a given time over an extended area. The......
weather modification
weather modification, the deliberate or the inadvertent alternation of atmospheric conditions by human activity,......
weather satellite
weather satellite, any of a class of Earth satellites designed to monitor meteorological conditions (see Earth...
weathering
weathering, disintegration or alteration of rock in its natural or original position at or near the Earth’s surface......
Weichsel Glacial Stage
Weichsel Glacial Stage, major division of late Pleistocene deposits and time in western Europe (the Pleistocene......
welded tuff
welded tuff, rock composed of compacted volcanic ejecta (see...
Wenlock Series
Wenlock Series, the second of four main divisions (in ascending order) of the Silurian System, representing those......
West African monsoon
West African monsoon, a major wind system that affects West African regions between latitudes 9° and 20° N and......
West Greenland Current
West Greenland Current, cool flow of water proceeding northward along the west coast of Greenland. See Greenland...
wet equatorial climate
wet equatorial climate, major climate type of the Köppen classification characterized by consistently high temperatures......
Whakaari/White Island
Whakaari/White Island, island in the Bay of Plenty, 43 miles (69 km) west of Cape Runaway, eastern North Island,......
What Causes a Drought?
Droughts occur when evaporation and transpiration rates consistently exceed precipitation over an extended period......
What Causes a Rainbow?
What Causes a Rainbow?, The formation of a rainbow begins with the refraction of sunlight as it enters a raindrop.......
What Causes a Volcano to Erupt?
Volcanic eruptions are among the most stunning phenomena in the natural world. Volcanoes erupt because of the way......
What Causes Acid Rain?
The main contributors to acid rain are sulfur dioxide (SO2) and nitrogen oxides (NOx; the combination of NO and......
What Causes Soil Erosion?
Soil erosion, like rock erosion, is caused by the movement of water and wind, and glaciers. Since soil (whether......
What Causes the Northern and Southern Lights?
The auroras—the aurora borealis (or northern lights) in the Northern Hemisphere, and the aurora australis (the......
What Causes Tides in the Ocean?
Tides in the ocean are primarily caused by the gravitational forces exerted by the Moon and the Sun on Earth. The......
What Causes Tsunamis?
As natural disasters go, tsunamis are among the worst in terms of overall destruction and loss of life. They rival......
What Happens to Earth If the Amazon Rainforest Is Completely Burned?
Metaphorically speaking, the vast tropical rainforest in South America’s Amazon River basin is often called the......
What Is an Aftershock?
Earth is an active place full of storms, fast-moving river and ocean currents, volcanoes, and earthquakes. Continents......
What Is Earth’s Velocity?
Earth has several velocities. There is the velocity with which it rotates on its axis. A point on Earth’s Equator......
What Is Known (and Not Known) About Contrails
Contrail is short for “condensation trail.” A condensation trail is a streamer of cloud sometimes observed behind......
What Is the Difference Between a Meteotsunami, a Seiche, and a Storm Surge?
A meteotsunami is a large sea wave, with a wave height of two metres (about 6 feet) or more. Unlike seismic tsunamis,......
What Is the Difference Between a Typhoon and a Super Typhoon?
The terms typhoon and hurricane are regional names for the same weather phenomenon, the tropical cyclone. Tropical......
What Makes a Wave Go Rogue?
Many a tall tale has been inspired by the world’s oceans, from stories of mysterious sea monsters to legends about......
What Was the Little Ice Age?
When most people think of ice ages, or “glacial ages,” they often envision cavemen, woolly mammoths, and vast plains......
What Would Happen if Earth Stopped Rotating?
If Earth were to suddenly stop rotating, the consequences would be catastrophic and far-reaching, affecting everything......
What’s the Difference Between Global Warming and Climate Change?
People often confuse the concepts of global warming and climate change, and it doesn’t help that media companies......
What’s the Difference Between Weather and Climate?
Adding confusion to the politics of climate change and global warming in the press is the assumption that the terms......
When Does Summer Start?
Many climate scientists define the start of summer in terms of meteorological phenomena and the calendar year.......
When Katrina Struck
Between August 23 and 29, 2005, a tropical depression called “Katrina” grew into one of the most destructive storms......
whirlpool
whirlpool, rotary oceanic current, a large-scale eddy that is produced by the interaction of rising and falling......
whirlwind
whirlwind, a small-diameter columnar vortex of rapidly swirling air. A broad spectrum of vortices occurs in the......
White Island volcanic eruption of 2019
White Island volcanic eruption of 2019, volcanic eruption on December 9, 2019, on Whakaari/White Island, located......
white mica
white mica, fine-grained variety of any of the silicate minerals muscovite, paragonite, or talc...
Why are Higher Elevations Colder?
Higher elevations are colder primarily due to the decrease in atmospheric pressure that results from the expansion......
Why Are Rainbows Curved?
Rainbows are curved because of the way sunlight interacts with water droplets in the atmosphere. When sunlight......
Why Are Rip Currents Dangerous?
Rip currents are dangerous primarily because they are often more powerful than they initially seem and move quickly,......
Why Do Stars Twinkle?
Light emitted from stars does not actually twinkle but only appears to twinkle when viewed from Earth. As starlight......
Why Do We Have Seasons?
Seasons occur due to the tilt of Earth’s axis, which is approximately 23.5°. This tilt causes Earth’s two hemispheres......
Why Does a Mushroom Cloud Look Like a Mushroom?
A mushroom cloud is the iconic and terrifying result of a thermonuclear explosion, but actually a mushroom cloud......
Why Does the Earth Rotate?
The Earth rotates because of the conservation of angular momentum acquired from the rotation of the solar nebula,......
Why Does the Tropic of Cancer’s Location on Earth Move Over Time?
The Tropic of Cancer is a line of latitude approximately 23°27′ north of Earth’s Equator. This latitude corresponds......
Why Does the United States Have More Tornadoes than Any Other Country?
The United States experiences the most tornadoes of any country in the world: more than 1,000 per year have been......
Why Is Summer Warmer Than Winter?
The temperature people feel outside is largely based on the absorption of radiant energy from the Sun. Differing......
Why Is the Huang He River Known as China’s Sorrow?
The Huang He, also known as the Yellow River, is often referred to as “China’s Sorrow” due to its long history......
Why Is the Ocean Salty?
“Water, water everywhere,/ Nor any drop to drink.” This famous line, spoken by the lost sailor in Samuel Taylor......
Why Is the Sky Blue?
One of the perennial questions of childhood is “Why is the sky blue?” You may have asked this as a child, or you......
Why Is There Fresh and Salt Water on Earth?
Rain and other forms of precipitation fall on our planet as slightly acidic fresh water. As some of this water......
Wichita orogeny
Wichita orogeny, a period of block faulting in the southern part of the Wichita–Arbuckle System in western Oklahoma......
willemite
willemite, white or greenish yellow silicate mineral, zinc silicate, Zn2SiO4, that is found as crystals, grains,......
wind
wind, in climatology, the movement of air relative to the surface of the Earth. Winds play a significant role in......
wind chill
wind chill, a measure of the rate of heat loss from skin that is exposed to the air. It is based on the fact that,......
wind rose
wind rose, map diagram that summarizes information about the wind at a particular location over a specified time......
wind shear
wind shear, rapid change in wind velocity or direction. A very narrow zone of abrupt velocity change is known as......
windstorm
windstorm, a wind that is strong enough to cause at least light damage to trees and buildings and may or may not......
winter
winter, coldest season of the year, between autumn and spring; the name comes from an old Germanic word that means......
Wisconsin Glacial Stage
Wisconsin Glacial Stage, most recent major division of Pleistocene time and deposits in North America, which began......
witherite
witherite, a carbonate mineral, barium carbonate (BaCO3), that is, with the exception of barite, the most common......
Witteberg series
Witteberg series, uppermost member of the Cape System of sedimentary rocks in South Africa. It consists of about......
wolframite
wolframite, chief ore of tungsten, commonly associated with tin ore in and around granite. Such occurrences include......
wollastonite
wollastonite, white, glassy silicate mineral that commonly occurs as masses or tabular crystals with other calcium-containing......
Wordian Stage
Wordian Stage, second of three stages of the Middle Permian (Guadalupian) Series, made up of all rocks deposited......
World Meteorological Organization
World Meteorological Organization (WMO), specialized agency of the United Nations (UN) created to promote the establishment......
Wuchiapingian Stage
Wuchiapingian Stage, first of two stages of the Upper Permian (Lopingian) Series, encompassing all rocks deposited......
wulfenite
wulfenite, lead molybdate, PbMoO4, a minor source of molybdenum and the second most common molybdenum mineral.......
wurtzite
wurtzite, a zinc sulfide mineral that occurs typically in Potosí, Bolivia; Butte, Mont.; and Goldfield, Nev. It......
Würm glacial stage
Würm glacial stage, major division of late Pleistocene deposits and time in Alpine Europe (the Pleistocene epoch......
xenolith
xenolith, rock fragment within an intrusive igneous body that is unrelated to the igneous body itself. Xenoliths,......
xenotime
xenotime, widely distributed phosphate mineral, yttrium phosphate (YPO4), though large proportions of erbium commonly......
Yangtze River floods
Yangtze River floods, floods of the Yangtze River (Chang Jiang) in central and eastern China that have occurred......

Earth Sciences Encyclopedia Articles By Title