How exactly do deserts form?
480792
Deserts can form in several ways that I know of...\n\nRainshadow effect on the leeward side of a mountain range. Most of the water is wrenched out of the air masses before they reach the other side of the range. This is due to the lifting of the air. It is forced to rise, condenses due to adiabatic cooling, & precipitates.\n\nThe most influential cause would be high pressure belts located around the world. These places are roughly located around the tropics of cancer & capricorn. In these areas, the high pressure is pushing down air. When there is a continuous belt of high pressure, air doesn't rise. If air doesn't rise then clouds can't form & rain won't happen. The Sahara & the Kalahari in Africa are examples.\n\nAnother would be inland deserts. They are so far removed from sources of moisture that they simply never get any. If I am not mistaken, the Gobi Desert is one.
808478
Whilst still below the surface it is called magma. Rocks which from from magma which has not been extruded at the surface cool more slowly (as they are at greater depth and hence higher temperatures) and thus have time to grow larger crystals before solidifying, producing a coarse-grained texture. These rocks are referred to as 'plutonic' and include gabbros, diorites, and good old granite. (You'll notice gabbros are darker due to their higher content of iron, etc - where as granites are a lighter colour as they are more rich in silica).\n\nLiquid rock at the surface is referred to as lava, and cools to form volcanic rocks such as basalts, andesites, and rhyolites (and obsidian, which is a really cool black volcanic glass). Due to cooling faster, volcanic rocks are quite fine-grained: if you look at a granite, you'll see indiviual crystals of the minerals (those little black or shiny silver-ish specks, or the large-ish pink or white crystals of feldspar) whereas to the naked eye, a volcanic rock such as basalt often looks rather like just a grey rock! (Looks pretty wicked under the polarizing microscope though...!)
50625
Yes it is considered a desert. It gets slightly more rainfall than the Sahara Desert, making it the largest desert on earth.
522348
This will create land & sea breezes.\n\nLand (sand) gains & loses heat faster than water due to water's latent heat properties.\n\nDuring the day, the land heats up faster than the water. A low pressure will develop over the land. This means that the air above the ground is warmed & will rise.\n\nSince air pressure will equalize, air from over the sea will move inland to replace the air that was lifted. A convection current starts. This is a sea breeze. (winds are named for the direction they come from.)\n\nThe opposite occurs at night. The land cools faster than the water. Since the water is warmer at night, a low pressure cell forms over the sea.\n\nHigher pressure from over land moves toward the low pressure to equalize. This is called a land breeze b/c it comes from the land.
478890
Generally desert.  Look it up at the library or online - you can do that, ya know.
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* Igneous Rocks\nIgneous rocks are called fire rocks and are formed either underground or above ground. Underground, they are formed when the melted rock, called magma, deep within the earth becomes trapped in small pockets. As these pockets of magma cool slowly underground, the magma becomes igneous rocks. \n\nIgneous rocks are also formed when volcanoes erupt, causing the magma to rise above the earth's surface. When magma appears above the earth, it is called lava. Igneous rocks are formed as the lava cools above ground.\n\n* Metamorphic Rocks\nMetamorphic rocks are rocks that have "morphed" into another kind of rock. These rocks were once igneous or sedimentary rocks. How do sedimentary and igneous rocks change? The rocks are under tons and tons of pressure, which fosters heat build up, and this causes them to change. If you exam metamorphic rock samples closely, you'll discover how flattened some of the grains in the rock are.\n\n* Sedimentary Rocks\nFor thousands, even millions of years, little pieces of our earth have been eroded--broken down and worn away\nby wind and water. These little bits of our earth are washed downstream where they settle to the bottom of the rivers, lakes, and oceans. Layer after layer of eroded earth is deposited on top of each. These layers are pressed down more and more through time, until the bottom layers slowly turn into rock.
939745
Antarctica is the largest "cold" desert.  YES,  it is classified as a desert! It doesn't get rainfall that plants can use it only gets snow.\n\nThe largest hot desert would be the sahara in northern Africa.
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large rocks break into smaller rocks by means or erosion, and by water seeping into cracks and freezing.  Ice may be rarer in deserts, but it is not unknown.  Wind also plays a role in erosion, but much less.  In some cases, rocks might have been formed in other places, and carried to distant places by rivers or glaciers.  Deserts weren't always deserts--a place that is today a desert might have once been a swamp, a prarie, or the bottom of a lake or sea.
152515
Here is one of the best websites on the deserts of the Southwestern USA, which includes desert life, some geology, and descriptions of the deserts.\nhttp://www.desertusa.com/flow.html\n\nCalifornia has some wondrous deserts, with miles and miles of open wild spaces. The main deserts in California are the Sonoran Desert, the Mojave Desert, and portions of the Great Basin Desert. Other names exist in common usage for some portions of these deserts. \n\nThere is also a list of good books on deserts on the DesertUSA website:\nhttp://www.desertusa.com/web_cart/db/pages/chi.html\n\nTo learn more about what conditions create a desert check out the UC Berkeley website on Desert Biomes at:\nhttp://www.ucmp.berkeley.edu/glossary/gloss5/biome/deserts.html\n\nThe USGS is another great resource for information on deserts:\nhttp://pubs.usgs.gov/gip/deserts/
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Planet formation is still somewhat of a mystery, but astronomers believe they understand the basic process. The best explanation to be accepted by most astronomers is known as the solar nebula hypothesis. Stars are formed from giant clouds of gas and dust known as nebulae. Gravity causes the matter in the nebula to coalesce. Gravity soon causes the central part of the nebula to collapse and form a star. The rest of the gas and dust forms a flat, rotating ring around the new star. Eventually the gravity of the new star begins to pull matter towards it. Small whirlpools of spinning matter form within this disk. Gravity causes these whirlpools to aggregate into small masses known as planetesimals. These planetesimals continue growing, pulling in the matter around them. Gravity soon pulls them into a spherical shape. These small spheres may collide and merge with others as they grow in size and become what is known as a protoplanet. Sometimes, a smaller sphere of matter may become captured by a larger one and enter into an orbit, creating a moon. Over time, gravity causes the heavier elements in the protoplanets to separate from the lighter ones in a process called uniformitarianism. This forms the planet's metal core, rocky crust, and usually an atmosphere composed of gas. As the star and planets continue to grow, the dust and gas of the nebula begins to thin. Smaller chunks of condensed matter is left over in the outer regions of the disk. These form the Kuiper belt of planetoids and the Oort cloud of comets. Eventually the solar wind from the star will blow away the excess gas and dust. A new solar system has been born. The process is slow and takes millions of years. Many stars have been observed to have flat disks of matter around them. These could very well be new solar systems in the making.
566412
It is very easy Deserts are sand, dunes, diferent kinds of cactus, small bushes, some animals like lizards, insects variety of them, and you can add an Oasis to make it more interest in in the Oasis there are Palms a few, water, you can put a small lake. tents, camels form a caravan in the desert.
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I've seen soldiers doing this in the desert: \nThey dig a small hole in the sand and put urine in it. They put a cup in the middle of this hole, and on top they put a clear plastic cloth, with a stone in the middle, so the lower part is right above the cup. Water from urine evaporates quickly an begins droping in the cup. They actually drink this and they say its 100% pure water.\nThis is just one way how it can be done.
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A desert is defined by its low rainfall record, hence why you can get hot, cold and frigid deserts.\n\nDeserts can be caused by a number of factors, for example mountains surrounding the area cause rain to fall on their slopes rather than further inland so creating the arid conditions.(can't think of an example for this but there are several)\n\nThe area may be so far inland that the damp winds from the sea fail to reach it.  When combined with a hot climate severe desert conditions occur. (Death Valley)\n\nThere may be a cold current running along the coast which causes coastal fog and precipitation, preventing it raining inland. (Patagonian Desert)\n\nThe sand is the product of weathering on the rock, the hot temperatures during the day cause the rocks to expand, the rocks are made up of different minerls and colours of crystals (grains) due to colour some expand more than others, this can break the rock surface down. (Intergranular errosion).  The wind picks up the bits and hits them against other rocks, turning the lumps to powder (mechanical errosion).\n\nwhen rain does fall the water scours rock debris off the surface causing the pieces to rub over each other (more mechanical errosion).  When drying out in the heat the water evapourates leaving salt deposits behind, these can dissole minerals in the rock (chemical errosion) and can cause slat pillars which are capable of lifting erroded rock layers off the surface.
258535
Mountains, plateau, deserts
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There are three ways actually:\n1. Rainwater soaks into the ground. Almost all soil will allow water to soak in and as it goes downward it encounters rock which also has small holes called pores that water can soak into. This is how water gets into wells that we drink from or use for irrigation. \n\nThe other two types do not always fit the definition of 'groundwater' but are found beneath the earth's surface:\n\n2. When rocks like sandstone are formed, they are mostly formed (deposited) beneath the ocean or under a river delta. They are filled with water when they form and this water is often trapped there by sediments like clay that deposit over the water filled sandstone. This water is often saltwater. \n\n3. When some rocks deep in the earth undergo a process called metamorphism they chemically expel water. Many rocks have water bound up as part of their chemical content and when this rock changes from pressure or heat the water is released. Some types of clay will also release water that is bound up chemically in the clay when they are buried and under higher temperature and pressure.
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The Sahara is the world's largest hot desert, over 9,000,000 km² (3,500,000 mi²).  \n\nThe volume of a grain of quartz sand with a diameter of 0.060 mm (a lower bound) is 1.13 x 10^-13 m^3 with a mass of 3.00 x 10-13 g. As an upper bound, the volume and mass of a grain of sand with a diameter of 2.10 mm are 4.85 x 10-9 m3 and 1.28 x 10-8 g.[1].\n\nThe deposits of the modern-day Sahara are generally less than 100 meters thick, though there are some sandy landforms that can reach 450 meters high. (3)\n\nArea of the Sahara: 9 000 000 (km^2) = 9.0 × 10^12 m^2.\nDepth of the sand in the Sahara: approx 100m\nVolume of sand in the sahara: (9.0*10^12)*(100m) = 9.0*10^14 m^3.\nVolume of a grain of sand: 1.13 x 10^-13 m^3\n\nTherefore the # of grains of sand in the Sahara is: (9.0*10^14 m^3)/(1.13 x 10^-13 m^3) = approx 8.0x10^27 grains of sand or 8000000000000000000000000000 grains of sand or 8 octillion grains of sand.
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A tropical desert consists of barren land over which rainfall is too limited to support vegetation. So why are such desolate and hostile places, like deserts, important to study? \n\nFirstly, desert studies help us predict possible future changes to the environment and how to avoid damaging it. In his book The Desert of Southeast Arabia, Ken Glennie takes us on a journey back in time to when Arabia was a much greener place, and he explains how global climate made it so barren.\n\nSecondly, in many parts of the world, such as Oman, Saudi Arabia, Europe’s North Sea and the United States, hydrocarbons are found in ancient dune sand reservoirs. Can we unravel the depositional and stratigraphical intricacies of these ancient gas- and oil-bearing reservoirs by studying modern deserts? Ken pioneered the answer to this question with his studies of both modern deserts and the reservoirs of the Permian Rotliegend Red Beds of northwest Europe. \n\nKen started writing this book 10 years ago for students; this is one reason for the extensive Glossary at the back. After many modifications and revisions, his book now provides a different perspective to a well-known topic. Its simplicity, detailed descriptions and illustrations will undoubtedly appeal to students, desert travelers and scientists. Of great value, especially when used in conjunction with studies on the ground, are the satellite images (Landsat) seen here in spectacular colour. None of these images, however, can replace seeing the desert rocks and sediments first hand. In this book, Ken shares his vast knowledge of the Arabian Desert, and exquisite collection of photos taken on the ground and from the air.