Desert Introduction Classification And Images Collection

Introduction:

Dry areas created by global circulation patterns contain most of the deserts on the Earth. The deserts of world are not restricted by latitude, longitude, or elevation. They occur from areas close to the poles down to areas near the Equator. The People's Republic of China has both the highest desert, the Qaidam Depression that is 2,600 meters above sea level, and one of the lowest deserts, the Turpan Depression that is 150 meters below sea level. Deserts are not confined to Earth. The atmospheric circulation patterns of other terrestrial planets with gaseous envelopes also depend on the rotation of those planets, the tilts of their axes, their distances from the Sun, and the composition and density of their atmospheres. Except for the poles, the entire surface of Mars is a desert. Venus also may support deserts. The Thar Desert is the Great Indian Desert.

Classification:

Deserts are classified by their geographical location and dominant weather pattern as trade wind, midlatitude, rain shadow, coastal, monsoon, or polar deserts. Former desert areas presently in nonarid environments are paleodeserts, and extraterrestrial deserts exist on other planets.

1. Trade wind deserts:

The trade winds in two belts on the equatorial sides of the Horse Latitudes heat up as they move toward the Equator. These dry winds dissipate cloud cover, allowing more sunlight to heat the land. Most of the major deserts of the world lie in areas crossed by the trade winds. The world's largest desert, the Sahara of North Africa, which has experienced temperatures as high as 57° C, is a trade wind desert. 

2. Midlatitude deserts:

Midlatitude deserts occur between 30° and 50° N. and S., poleward of the subtropical highpressure zones. These deserts are in interior drainage basins far from oceans and have a wide range of annual temperatures. The Sonoran Desert of southwestern North America is a typical midlatitude desert.

3. Rain shadow deserts:

Rain shadow deserts are formed because tall mountain ranges prevent moisture-rich clouds from reaching areas on the lee, or protected side, of the range. As air rises over the mountain, water is precipitated and the air loses its moisture content. A desert is formed in the leeside "shadow" of the range. 

4. Coastal deserts:

Coastal deserts generally are found on the western edges of continents near the Tropics of Cancer and Capricorn. They are affected by cold ocean currents that parallel the coast. Because local wind systems dominate the trade winds, these deserts are less stable than other deserts. Winter fogs, produced by upwelling cold currents, frequently blanket coastal deserts and block solar radiation. Coastal deserts are relatively complex because they are at the juncture of terrestrial, oceanic, and atmospheric systems. A coastal desert, the Atacama of South America, is the Earth's driest desert. In the Atacama, measurable rainfall--1 millimeter or more of rain--may occur as infrequently as once every 5-20 years.

 

5. Monsoon deserts:

Monsoon derived from an Arabic word for "season," refers to a wind system with pronounced seasonal reversal. Monsoons develop in response to temperature variations between continents and oceans. The southeast trade winds of the Indian Ocean, for example, provide heavy summer rains in India as they move onshore. As the monsoon crosses India, it loses moisture on the eastern slopes of the Aravalli Range. The Rajasthan Desert of India and the Thar Desert of Pakistan are parts of a monsoon desert.

6. Polar deserts:

Polar deserts are areas with annual precipitation less than 250 millimeters and a mean temperature during the warmest month of less than 10° C. Polar deserts on the Earth cover nearly 5 million square kilometers and are mostly bedrock or gravel plains. Sand dunes are not prominent features in these deserts, but snow dunes occur commonly in areas where precipitation is locally more abundant. Temperature changes in polar deserts frequently cross the freezing point of water. This "freeze-thaw" alternation forms patterned textures on the ground, as much as 5 meters in diameter.

7. Extraterrestrial deserts:

Mars is the only other planet on which we have identified wind-shaped (eolian) features. Although its surface atmospheric pressure is only about one-hundredth that of Earth, global circulation patterns on Mars have formed a circumpolar sand sea of more than five million square kilometers, an area greater than the Empty Quarter of Saudi Arabia, the largest sand sea on our planet. Martian sand seas consist predominantly of crescent-shaped dunes on plains near the perennial ice cap of the north polar area. Smaller dune fields occupy the floors of many large craters in the polar regions. 

Images:

Desert's Image

Desert's Image

Desert's Image

Desert's Image

Desert's Image

Desert's Image

Earthquake Introduction Cause Effect And Images

Introduction:

An earthquake is the result of a sudden release of energy in the Earth's crust that create sseismic waves. Earthquakes are measured using observations from seismometers. The moment magnitude is the most common scale on which earthquakes larger than approximately 5 are reported for the entire globe. The more numerous earthquakes smaller than magnitude 5 reported by national seismological observatories are measured mostly on the local magnitude scale, also referred to as the Richter scale. These two scales are numerically similar over their range of validity. Magnitude 3 or lower earthquakes are mostly almost imperceptible and magnitude 7 and over potentially cause serious damage over large areas, depending on their depth. The largest earthquakes in historic times have been of magnitude slightly over 9, although there is no limit to the possible magnitude. The most recent large earthquake of magnitude 9.0 or larger was a 9.0 magnitude earthquake in Japan in 2011 and it was the largest Japanese earthquake since records began. Intensity of shaking is measured on the modified Mercalli scale.

  Cause:

Earthquakes are caused by tectonic movements in the Earth's crust. The main cause is that when tectonic plates collide one rides over the other causing orogeny earthquakes and volcanoes.The boundaries between moving plates form the largest fault surfaces on Earth. When they stick relative motion between the plates leads to increasing stress. This continues until the stress rises and breaks suddenly allowing sliding over the locked portion of the fault and releasing the stored energy.

Earthquake Effect In As Follows:

1. Shaking and ground rupture

2. Landslides and avalanches
3. Fires
4. Soil liquefaction
5. Tsunami
6. Floods
7.Human impacts

Images:

Image Of Earthquake

Image Of Earthquake

Image Of Earthquake

Image Of Earthquake

Image Of Earthquake

Image Of Earthquake

Image Of Earthquake

Global warming And Its Effect On Us How To Protect Global Warming

Cause Of Global Warming

Short Essay on Global Warming How To Protect And Cause Of Short Essay on Global Warming:

Global Warming also cause sea water to swell up.There are many causes of Global Warming. This global warming is caused due to Greenhouse Effect. What is greenhouse effect? It is a condition in which Earth’s heat trapping increases more from the normal levels. This can catastrophically reduce mankind’s ability to grow foods and destroy wildlife.The effects of Global Warming is very dangerous for our existence and survival. The sun’s scorching heat comes to earth in a direct way. Therefore, the earth’s surface becomes seriously heated. Agriculture, forestry and fishery is seriously be damaged. Global Warming is a major problem which our environment faces today terribly. 

Global Warming Image

The destruction and burning down of tropical forests , traffic clogging up the city streets , rapid growth of unplanned industries, the use of CFCs in packaging and manufacturing products, the use of detergents etc.The temperature effects of carbon dioxide and water vapor combine together to have a long range impact on the global climate. As the surface temperature increase, the evaporation of surface water increase, thereby raising the temperature further.Global Warming is too serious for the world any longer to ignore it’s danger or split into opposing factions on it.

Global warming  Cause

Global warming Picture

Cause Of Global warming