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Dune Sea
An erg (also sand sea or dune sea, or sand sheet if it lacks dunes) is a broad, flat area of desert covered with wind-swept sand with little or no vegetative cover. The word is derived from the Arabic word ''ʿarq'' (), meaning "dune field". Strictly speaking, an erg is defined as a desert area that contains more than of aeolian or wind-blown sand and where sand covers more than 20% of the surface. Smaller areas are known as "dune fields". The largest hot desert in the world, the Sahara, covers and contains several ergs, such as the Chech Erg and the Issaouane Erg in Algeria. Approximately 85% of all the Earth's mobile sand is found in ergs that are greater than . Ergs are also found on other celestial bodies, such as Venus, Mars, and Saturn's moon Titan. Description Ergs are concentrated in two broad belts between 20° to 40°N and 20° to 40°S latitudes, which include regions crossed by the dry, subsiding air of the trade winds. Active ergs are limited to reg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terrestrial planet with a thin atmosphere (less than 1% that of Earth's), and has a crust primarily composed of elements similar to Earth's crust, as well as a core made of iron and nickel. Mars has surface features such as impact craters, valleys, dunes and polar ice caps. It has two small and irregularly shaped moons, Phobos (moon), Phobos and Deimos (moon), Deimos. Some of the most notable surface features on Mars include Olympus Mons, the largest volcano and List of tallest mountains in the Solar System, highest known mountain in the Solar System and Valles Marineris, one of the largest canyons in the Solar System. The North Polar Basin (Mars), Borealis basin in the Northern Hemisphere covers approximately 40% of the planet and may be a la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southwest Asia
Western Asia, West Asia, or Southwest Asia, is the westernmost subregion of the larger geographical region of Asia, as defined by some academics, UN bodies and other institutions. It is almost entirely a part of the Middle East, and includes Anatolia, the Arabian Peninsula, Iran, Mesopotamia, the Armenian highlands, Armenian Highlands, the Levant, the island of Cyprus, the Sinai Peninsula, and partly the Caucasus, Caucasus Region (Transcaucasia). The region is considered to be separated from Africa by the Isthmus of Suez in Egypt, and separated from Europe by the waterways of the Turkish Straits and the watershed of the Greater Caucasus. Central Asia lies to its northeast, while South Asia lies to its east. Twelve seas surround the region (clockwise): the Aegean Sea, the Sea of Marmara, the Black Sea, the Caspian Sea, the Persian Gulf, the Gulf of Oman, the Arabian Sea, the Gulf of Aden, the Red Sea, the Gulf of Aqaba, the Gulf of Suez, and the Mediterranean Sea. Western Asia cove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Asia
Central Asia, also known as Middle Asia, is a subregion, region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes the former Soviet Union, Soviet republics of the Soviet Union, republics of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan, which are colloquially referred to as the "-stans" as the countries all have names ending with the Persian language, Persian suffix "-stan", meaning "land of". The current geographical location of Central Asia was formerly part of the historic region of Turkestan, Turkistan, also known as Turan. In the pre-Islamic and early Islamic eras ( and earlier) Central Asia was inhabited predominantly by Iranian peoples, populated by Eastern Iranian languages, Eastern Iranian-speaking Bactrians, Sogdians, Khwarezmian language, Chorasmians and the semi-nomadic Scythians and Dahae. After expansion by Turkic peop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area and 20% of its land area.Sayre, April Pulley (1999), ''Africa'', Twenty-First Century Books. . With billion people as of , it accounts for about of the world's human population. Africa's population is the youngest amongst all the continents; the median age in 2012 was 19.7, when the worldwide median age was 30.4. Despite a wide range of natural resources, Africa is the least wealthy continent per capita and second-least wealthy by total wealth, behind Oceania. Scholars have attributed this to different factors including geography, climate, tribalism, colonialism, the Cold War, neocolonialism, lack of democracy, and corruption. Despite this low concentration of wealth, recent economic expansion and the large and young population make Afr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southern Africa
Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number of river systems; the Zambezi River being the most prominent. The Zambezi flows from the northwest corner of Zambia and western Angola to the Indian Ocean on the coast of Mozambique. Along the way, the Zambezi River flows over the mighty Victoria Falls on the border between Zambia and Zimbabwe. Victoria Falls is one of the largest waterfalls in the world and a major tourist attraction for the region. Southern Africa includes both subtropical and temperate climates, with the Tropic of Capricorn running through the middle of the region, dividing it into its subtropical and temperate halves. Countries commonly included in Southern Africa include Angola, Botswana, the Comoros, Eswatini, Lesotho, Madagascar, Malawi, Mauritius, Mozambique, Namib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Africa
North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in the west, to Egypt's Suez Canal. Varying sources limit it to the countries of Algeria, Libya, Morocco, and Tunisia, a region that was known by the French during colonial times as "''Afrique du Nord''" and is known by Arabs as the Maghreb ("West", ''The western part of Arab World''). The United Nations definition includes Morocco, Algeria, Tunisia, Libya, Egypt, Sudan, and the Western Sahara, the territory disputed between Morocco and the Sahrawi Republic. The African Union definition includes the Western Sahara and Mauritania but not Sudan. When used in the term Middle East and North Africa (MENA), it often refers only to the countries of the Maghreb. North Africa includes the Spanish cities of Ceuta and Melilla, and plazas de s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trade Wind
The trade winds or easterlies are the permanent east-to-west prevailing winds that flow in the Earth's equatorial region. The trade winds blow mainly from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisphere, strengthening during the winter and when the Arctic oscillation is in its warm phase. Trade winds have been used by captains of sailing ships to cross the world's oceans for centuries. They enabled colonial expansion into the Americas, and trade routes to become established across the Atlantic Ocean and the Pacific Ocean. In meteorology, they act as the steering flow for tropical storms that form over the Atlantic, Pacific, and southern Indian oceans and make landfall in North America, Southeast Asia, and Madagascar and East Africa. Shallow cumulus clouds are seen within trade wind regimes and are capped from becoming taller by a trade wind inversion, which is caused by descending air aloft from within the subtropical ridge. The weak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
40th Parallel South
The 40th parallel south is a circle of latitude that is 40 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, the Indian Ocean, Australasia, the Pacific Ocean and South America. Its long oceanic stretches are the northern domain of the Roaring Forties. On 21 June 2018, the sun is at 26.17° in the sky and at 73.83° on 21 December, in King Island, Tasmania, which is near the 40th parallel. The maximum altitude of the Sun is > 35.00º in April and > 28.00º in May. Around the world Starting at the Prime Meridian and heading eastwards, the parallel 40° south passes through: : See also *39th parallel south * 41st parallel south *Roaring Forties *Project Loon Loon LLC was an Alphabet Inc. subsidiary working on providing Internet access to rural and remote areas. The company used high-altitude balloons in the stratosphere at an altitude of to to create an aerial wireless network with up to 1 Mbi ... References {{geographical coordinates, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
20th Parallel South
The 20th parallel south is a circle of latitude that is 20 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, Africa, the Indian Ocean, Australasia, the Pacific Ocean and South America. Around the world Starting at the Prime Meridian and heading eastwards, the parallel 20° south passes through: See also *19th parallel south The 19th parallel south is a circle of latitude that is 19 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, Africa, the Indian Ocean, Australasia, the Pacific Ocean and South America. Around the world Starting at t ... * 21st parallel south {{geographical coordinates, state=collapsed s20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
40th Parallel North
The 40th parallel north is a circle of latitude that is 40 degrees north of the Earth's equatorial plane. It crosses Europe, the Mediterranean Sea, Asia, the Pacific Ocean, North America, and the Atlantic Ocean. At this latitude the sun is visible for 15 hours, 1 minute and 28 seconds during the summer solstice and 9 hours, 20 minutes during the winter solstice. On 21 June, the maximum altitude of the sun is 73.44 degrees, while it's 26.56 degrees on 21 December. The maximum altitude of the Sun is > 35.00º in October and > 28.00º in November. The 40th parallel north is the southern baseline for Canada's National Topographic System. Around the world Starting in Spain at the Prime Meridian and heading eastwards, the parallel 40° north passes through: : United States The parallel 40° north forms the boundary between the states of Kansas and Nebraska. On 30 May 1854, the Kansas–Nebraska Act created the Territory of Kansas and the Territory of Nebraska divided by the pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
20th Parallel North
The 20th parallel north is a circle of latitude that is 20 degree (angle), degrees true north, north of the Earth, Earth's equator, equatorial plane. It crosses Africa, Asia, the Indian Ocean, the Pacific Ocean, North America, the Caribbean and the Atlantic Ocean. The parallel defines part of the Libya–Sudan border, border between Libya and Sudan. Within Sudan it defines the border between the Northern, Sudan, Northern and North Darfur states. At this latitude the sun is visible for 13 hours, 21 minutes during the summer solstice and 10 hours, 55 minutes during the winter solstice. On 21 June, the maximum altitude of the sun is 93.44 degrees and 46.56 degrees on 21 December. Around the world Starting at the Prime Meridian and heading eastwards, the parallel 20° north passes through: : See also *19th parallel north *21st parallel north References {{DEFAULTSORT:20th Parallel North Circles of latitude, n20 Libya–Sudan border ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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