nepal's diversity

Nepal measures about 800 kilometers (497 mi) along its himalayan axis by 150 to 250 kilometers (93 to 155 mi) across. With 147,181 square kilometers (56,827 sq mi) it slightly outranks Bangladesh or the state of Arkansas. Nepal is landlocked by India on three sides and China's Xizang Autonomous Region (Tibet) to the north. West Bengal's narrow Siliguri Corridor or Chicken's Neck separate Nepal and Bangladesh. To the east are India—and Bhutan. Nepal depends on India for transit facilities and access to the sea—the Bay of Bengal—even for most goods imported from China.

Geographic coordinates: 28°00′N 84°00′E / 28°N 84°E / 28; 84

Contents [hide]
1 The Land
1.1 The Terai Region
1.2 The Hill Region
1.3 The Mountain Region
2 Climate
3 Environment
4 River system
4.1 River Management
5 Area and boundaries
6 Resources and land use
7 Forests
8 Environmental concerns
9 See also
10 References
11 External links


[edit] The Land
For a small country, Nepal has tremendous geographic diversity. It rises from less than 100 metres (328 ft) elevation in the tropical Terai—the northern rim of the Gangetic Plain, beyond the perpetual snow line to some 90 peaks over 7,000 metres (22,966 ft) including Earth's highest 8,848 metres (29,029 ft) Mount Everest or Sagarmatha. In addition to the continuum from tropical warmth to cold comparable to polar regions, average annual precipitation varies from as little as 160 millimetres (6.3 in) in the rainshadow north of the Himalaya to as much as 5,500 millimetres (216.5 in) on windward slopes. [1]

Along a south-to-north transect, Nepal can be divided into three belts: Terai, Hill and Mountain Regions. In the other direction it is divided into three major river systems, from east to west: Koshi, Gandaki/Narayani and Karnali (including the Mahakali/Sarda along the western border), all tributaries of the Ganges. The Ganges-Yarlung Zangbo/Brahmaputra watershed largely coincides with the Nepal-Tibet border, however several Ganges tributaries rise inside Tibet.

[edit] The Terai Region
The Terai or Madhesh region begins at the Indian border and includes the northermost part of the flat, intensively farmed Gangetic Plain called the Outer Terai. This is culturally an extension of northern India with Hindi, Awadhi, Bhojpuri and Maithili spoken more than Nepali, however it was annexed to Nepal by conquest and by treaty with the British.

The Outer Terai ends at the first range of foothills called the Siwaliks or Churia. This range has a densely forested skirt of coarse alluvium called the bhabhar along its base. Below the bhabhar, finer, less permeable sediments force groundwater to the surface in a zone of springs and marshes. In Persian, terai refers to wet or marshy ground. Before the use of DDT it was dangerously infested with malaria. Nepal's rulers used it as a defensive frontier called the char kose jhadi (twelve kilometer forest)

Above the bhabhar belt, the Siwaliks rise to about 700 metres (2,297 ft) with peaks as high as 1,000 metres (3,281 ft), steeper on their southern flanks because of faults known as the Main Frontal Thrust. This range is composed of poorly consolidated, coarse sediments that do not retain water or support soil development so there is virtually no agricultural potential. Hillside vegetation is limited to scrub forest and the area functions as a deserted buffer zone allowing the development of distinctive cultures in valleys and hills further north. In several places beyond the Siwaliks there are dun valleys called Inner Terai with productive soil. Among these are Dang and Deukhuri in western Nepal and the Rapti Valley (Chitwan) in central Nepal. Population in these valleys was historically limited by malaria and mainly limited to the Tharu ethnic group that had developed genetic resistance. Around 1960 DDT came into use to suppress mosquitos and the way was open to settlement from the land-poor hills to the detriment of Tharus.

The Terai ends and the Hills begin at a higher range of foothills called the Mahabharat Range.

[edit] The Hill Region
Situated south of the Mountain Region, the Hill Region (Pahar in Nepali) is mostly between 700 and 4,000 metres (2,297 and 13,123 ft) altitude. This region begins at the Mahabharat Lekh (Lesser Himalaya) where a fault system called the Main Boundary Thrust creates an escarpment 1,000 to 1,500 metres (3,281 to 4,921 ft) high, to a crest between 1,500 and 2,700 metres (4,921 and 8,858 ft). These steep southern slopes are nearly uninhabited, thus an effective buffer between languages and culture in the Terai and Hill regions. Northern slopes are gentler and moderately well populated.

North of this range, Nepali-speaking Hindus and Newar merchants who also speak Newari densely populate valleys suited to rice cultivation as high as 2,000 metres (6,562 ft). The increasingly urbanized Kathmandu and Pokhara valleys fall within this region. Indigenous janajati ethnic groups—natively speaking highly localized Tibeto-Burman languages and dialects—populate hillsides up to about 3,000 metres (9,843 ft). This group includes Magar and Kham Magar west of Pokhara, Gurung south of the Annapurnas, Tamang around the periphery of Kathmandu Valley and Rai and Limbu further east. Beyond microclimates suited to rice cultivation and proximity to water for irrigation, these cultivate maize, millet, barley and potatoes as staple crops. Temperate and subtropical fruits are grown as cash crops. Marijuana is grown and processed into Charas (hashish), but less than was produced before international pressure persuaded the government to outlaw it in the 1970s. There is increasing reliance on animal husbandry with elevation, using land above 3,000 metres (9,843 ft) for summer grazing and moving herds to lower elevations in winter. Outside the rice-growing lower valleys, hill populations suffer chronic food deficits. Many menfolk find employment in the Terai, in India or overseas to earn cash for imported grain. The Hill region ends dramatically where the main Himalayan Range abruptly rises thousands of meters.

[edit] The Mountain Region

Perspective view of the Himalaya and Mount Everest as seen from space looking south-south-east from over the Tibetan Plateau. (annotated version)The Mountain Region or Parbat abruptly rises into the zone of perpetual snow along the Main Central Thust fault zone. South of this fault system, "hills" do not greatly exceed treeline at about 3,500 metres (11,483 ft). North of it the Himalayas rise as a virtual wall beyond the snowline at 5,000 to 5,500 metres (16,404 to 18,045 ft) to some 90 peaks over 7,000 metres (22,966 ft) and eight exceeding 8,000 metres (26,247 ft) including Mount Everest at 8,848 metres (29,029 ft) and Kanchenjunga at 8,598 metres (28,209 ft). Unlike the Mahabharats, the Himalaya are not continuous across Nepal. Instead there are some 20 subranges including the Kanchenjunga massif, Kumbu around Mt. Everest. Langtang north of Kathmandu, Annapurna north of Pokhara and Dhaulagiri further west, then Kanjiroba north of Jumla.

Alpine, often semi-arid valleys—including Humla, Jumla, Dolpo, Mustang, Manang and Khumbu-- cut between himalayan subranges or lie north of them. They are lightly populated by people with Tibetan affinities called Bhotiya or Bhutia including the famous Sherpas in Kumbu valley near Mount Everest. Permanent villages are found as high as 4,500 metres (14,764 ft) with summer encampments even higher. These peoples traditionally grazed yaks, grew cold-tolerant crops such as potatoes, barley and millet, and traded across the mountains, e.g. Tibetan salt for rice from lowlands in Nepal and India. Since the 1950s they have also found work as high altitude porters, guides, cooks and other accessories to tourism and alpinism.

Bhutiya language and culture extend north into Tibet proper, with the international border following the Himalayan crest in eastern Nepal. In central and western Nepal the border mostly follows the watershed between the Ganges and Yarlung Zangbo (Brahmaputra) basins along (about 6,000 metres (19,685 ft)) ranges tens of kilometers north of the highest peaks.

[edit] Climate

Satellite image of Nepal in October 2002Nepal has tremendous variation in climate. Its latitude is about the same as that of Florida so Terai land up to 500 meters (1,640 ft) has a fully tropical climate, with a subtropical zone extending up to 1,200 meters (3,937 ft) which is the lower limit of frost in winter. Warm temperate climates prevail from 1,200 to 2,400 meters (3,937 to 7,874 ft) where snow occasionally falls. Then there is a cold zone to 3,600 meters (11,811 ft) (treeline), a subarctic or alpine zone to 4,400 meters (14,436 ft) and fully arctic climate above that. Precipitation generally decreases from east to west with increasing distance from the Bay of Bengal, source of the summer monsoon. Eastern Nepal gets about 2,500 mm (98.4 in) annually; the Kathmandu area about 1,400 mm (55.1 in) and western Nepal about 1,000 mm (39.4 in). This pattern is modified by adabiatic effects as rising air masses cool and drop their moisture content on windward slopes, then warm up as they descend so relative humidity drops. Annual precipitation reaches 5,500 mm (216.5 in) on windward slopes in the Annapurna Himalaya beyond a relatively low stretch of the Mahabharat Range. In rainshadows beyond the high mountains, annual precipitation drops as low as 160 mm (6.3 in), creating a cold semi-desert.

Furthermore the year is divided into a wet season from June to September—as summer warmth over Inner Asia creates a low pressure zone that draws in air from the Indian Ocean—and a dry season from October to June as cold temperatures in the vast interior creates a high pressure zone causing dry air to flow outward. April and May are months of intense water stress when cumulative effects of the long dry season are exacerbated by temperatures rising over 40 °C (104 °F). Seasonal drought intensifies in the Siwaliks hills consisting of poorly-consolidated, coarse, highly permeable sediments that do not retain water, so hillsides are covered with tropical scrub forest that is extremely drought-tolerant. In fact outside marsh and riparian zones, most of Nepal's native vegetation is adapted to withstand drought, although less so at higher elevations where cooler temperatures mean less water stress.

The monsoon is preceded by a buildup of thunderstorm activity in the hills that helps farmers irrigate rice seedbeds. Sustained rain on average arrives in early June as rising temperatures over Inner Asia creates a low pressure zone that draws in air from the Indian Ocean, but this can vary up to a month. Significant failure of monsoon rains historically meant drought and famine while above-normal rains still cause flooding and landslides with losses in human lives, farmland and buildings. The monsoon also complicates transportation with roads and trails washing out while unpaved roads and airstrips may become unusable and cloud cover reduces safety margins for aviation. Rains diminish in September and generally end by mid-October, ushering in generally cool, clear, and dry weather, as well as the most relaxed and jovial period in Nepal. By this time, the harvest is completed and people are in a festive mood. The two biggest and most important Hindu festivals-- Dashain and Tihar (Dipawali)--arrive during this period, about one month apart. The postmonsoon season lasts until about December.

After the postmonsoon comes the winter monsoon, a strong northeasterly flow marked by occasional, short rainfalls in the lowlands and plains and snowfalls in the high-altitude areas. Precipitation varies from year to year but increases markedly with elevation. Adequate snowfall in the Himalaya is important for sufficient spring and summer meltwater for irrigation in the lower hills and valleys. At lower elevations, winter rainfall is needed for the success of winter crops such as wheat, barley and vegetables. In this season the Himalaya function as a barrier to cold air masses from Inner Asia, so southern Nepal and northern India have warmer winters than would otherwise be the case. April and May are dry and hot, especially below 1,200 meters (3,937 ft) where afternoon temperatures may exceed 40 °C (104 °F).

[edit] Environment
The dramatic changes in elevation along this transect result in a variety of biomes, from tropical savannas along the Indian border, to subtropical broadleaf and coniferous forests in the hills, to temperate broadleaf and coniferous forests on the slopes of the Himalaya, to montane grasslands and shrublands, and finally rock and ice at the highest elevations.

This corresponds to the Terai-Duar savanna and grasslands ecoregion.

Subtropical forests dominate the lower elevations of the Hill Region. They form a mosaic running east-west across Nepal, with Himalayan subtropical broadleaf forests between 500 and 1,000 metres (1,640 and 3,281 ft) and Himalayan subtropical pine forests between 1,000 and 2,000 metres (3,281 and 6,562 ft). At higher elevations, to 3,000 metres (9,843 ft), are found temperate broadleaf forests: eastern Himalayan broadleaf forests to the east of the Gandaki River and western Himalayan broadleaf forests to the west.

The native forests of the Mountain Region change from east to west as precipitation decreases. They can be broadly classified by their relation to the Gandaki River. From 3,000 to 4,000 metres (9,843 to 13,123 ft) are the eastern and western Himalayan subalpine conifer forests. To 5,500 metres (18,045 ft) are the eastern and western Himalayan alpine shrub and meadows.

[edit] River system
Nepal has three categories of rivers. The largest river systems—from east to west Koshi, Gandaki/Narayani, Karnali/Goghra and Mahakali -- originate in or beyond the high Himalaya and maintain substantial flows from glacial melt through the hot, droughty spring before the summer monsoon. These largest rivers cross the mountains in deep gorges before emerging onto the plains where they have deposited megafans exceeding 10,000 km2 (3,861 sq mi) area.

the Koshi is also called Sapta Koshi for its seven Himalayan tributaries: Indrawati, Bhote Koshi, Tama Koshi, Dudh Koshi, Liku, Arun, and Tamor. The Arun rises about 150 kilometers inside Tibet.

The Gandaki/Narayani also has seven Himalayan tributaries: Daraudi, Seti Gandaki, Madi, Kali, Marsyandi, Budhi, and Trisuli also called Sapta Gandaki. The Kali Gandaki flows between the 8,000-meter (26,247 ft) Dhaulagiri and Annapurna ranges in the world's deepest valley. After the seven upper tributaries have joined, the river becomes the Narayani inside Nepal, however it is called the Gandak in India.

The Karnali drains western Nepal, with the Bheri and Seti as major tributaries. The upper Karnali rises inside Tibet near sacred Lake Manasarovar and Mount Kailash. The area around these features is the hydrographic nexus of South Asia by containing the sources of the Indus, Sutlej, Ganges tributary Karnali and Yarlung Zangbo/Brahmaputra. It is the center of the universe according to traditional cosmography. The Mahakali or Kali along the Nepal-India border on the west joins the Karnali in India, where the river is known as Goghra or Ghaghara.

Second category rivers rise in the Middle Hills and Mahabharat Range, from east to west the Mechi, Kankai and Kamala south of the Kosi; the Bagmati that drains Kathmandu Valley between the Kosi and Gandaki systems, then the West Rapti and the Babai between the Gandaki and Karnali systems. Without glacial sources, annual flow regimes are more variable although limited flow persists through the dry season.

Third category rivers rise in the outermost Siwalik foothills and are mostly seasonal.

None of these river systems support significant commercial navigation. Instead, deep gorges create obstacles to establishing transport and communication networks and de-fragmenting the economy. Foot-trails are still primary transportation routes in many hill districts.


Nepal's towns, villages, rivers and peaks[edit] River Management
All three categories are capable of causing serious floods, for example the West Rapti in the second category is called Gorakhpur's Sorrow for its history of urban flooding. Koshi River in the first category caused a major flood in August 2008 in Bihar state, India after breaking through a poorly-maintained embankment just inside Nepal.

Since uplift and erosion are more or less in equilibrium in the Himalaya, rapid uplift is balanced by annual increments of cubic kilometers of sediments washing down from the mountains, then on the plains settling out of suspension on vast alluvial fans or inland deltas over which rivers meander and change course at least every few decades, causing some experts to question whether manmade embankments can contain the problem of flooding. Traditional Mithila culture along the lower Koshi in Nepal and Bihar celebrated the river as the giver of life for its fertile alluvial soil, yet also the taker of life through its catastrophic floods.

Another approach would be to build large dams—in gorges crossing the Mahabharat Range or further upstream—with storage capacities measured in cubic kilometers to capture high flows during the monsoon when there is usually enough rainfall on the plains if not flooding, then releasing water for hydroelectric generation and irrigation especially during the hot and dry pre-monsoon "summer". Nepal would appear to have unusual potential given its average annual 150 cm. of precipitation and thousands of meters of relief between mountains and plains, but there has only been limited development of this potential for example on the Kali Gandaki north of Tansen.

Building dams in Nepal is controversial for several reasons. First, the region is seismically active. Dam failures caused by earthquakes could cause tremendous death and destruction downstream, particularly on the densely populated Gangetic Plain. Second, global warming has led to the formation of glacial lakes dammed by unstable moraines. Sudden failures of these moraines could lead to cascading failures of manmade structures downstream. Third, sedimentation rates in the Himalaya are extremely high, leading to rapid loss of storage capacity as sediments accumulate behind dams. Fourth, there are complicated questions of cross-border equity in how India and Nepal would share costs and benefits that have proven difficult to resolve in the context of frequent acrimony between the two countries.

[edit] Area and boundaries
Area
Total: 147,181 km²
Land: 143,181 km²
Water: 4,000 km²
Area - comparative
Roughly 1⅔ Tasmania's size
Roughly twice New Brunswick's size
Slightly less than twice Scotland's size
Slightly larger than Arkansas
Land boundaries
Total: 2,926 km
Border countries: China 1,236 km, India 1,690 km
Coastline
0 km (landlocked)
Maritime claims
None (landlocked)
Elevation extremes
Lowest point: Kanchan Kalan 70 m
Highest point: Sagarmatha (Mount Everest) 8,848 m
[edit] Resources and land use
Natural resources
Quartz, water, timber, hydropower, scenic beauty, small deposits of lignite, copper, cobalt, iron ore
Land use
Arable land: 21.68%
Permanent crops: 0.64%
Other: 77.68% (2001)
Irrigated land
11,350 km² (1998 est.)
[edit] Forests
25.4% of Nepal's land area, or about 36,360 km2 (14,039 sq mi) is covered with forest according to FAO figures from 2005. FAO estimates that around 9.6% of Nepal's forest cover consists of primary forest which is relatively intact. About 12.1% Nepal's forest is classified as protected while about 21.4% is conserved according to FAO. About 5.1% Nepal's forests are classified as production forest. Between 2000-2005, Nepal lost about 2,640 km2 (1,019 sq mi) of forest. Nepal's 2000-2005 total deforestation rate was about 1.4% per year meaning it lost an average of 530 km2 (205 sq mi) of forest annually. Nepal's total deforestation rate from 1990-2000 was 920 km2 (355 sq mi) or 2.1% per year. The 2000-2005 true deforestation rate in Nepal, defined as the loss of primary forest, is -0.4% or 70 km2 (27 sq mi) per year.

Deforestation is driven by multiple processes. In the hills, conversion of forests to agricultural land—even on steep hillsides via terracing—is historically important, but has lessened in recent decades due to a shortage of remaining suitable terrain in the hills while mosquito suppression having opened formerly malarial land for settlement in the Terai. As a result, forest land in the Terai is being cleared by settlers.

In the hills, greater contemporary impacts involve degradation of forests rather than outright clearing. Degradation is caused by harvesting firewood, and to a lesser extent wood for traditional architecture. These harvests are often carried to unsustainable levels. Trees are also severely damaged by intensive harvesting of leaves as fodder, especially in the driest months preceding the summer monsoon. Households typically keep at least one cow or buffalo for milk production and may also keep oxen for agricultural labor. In addition goats are herded as the main source of meat that is culturally acceptable to upper-caste Hindus.

FAO Forestry Department Nepal Country Page
Ministry of Forests and Soil Conservation Nepal
Forestry Information in Nepal
[edit] Environmental concerns
Natural hazards
Severe thunderstorms, flooding, landslides, drought, and famine depending on the timing, intensity, and duration of the summer monsoons
Environment - current issues
Deforestation (overuse of wood for fuel and lack of alternatives); contaminated water (with human and animal wastes, agricultural runoff, and industrial effluents); wildlife conservation; vehicular emissions; High arsenic and microbiological levels in groundwater
Environment - international agreements
Party to: Biodiversity, Climate Change, Desertification, Endangered Species, Hazardous Wastes, Law of the Sea, Nuclear Test Ban, Ozone Layer Protection, Tropical Timber 83, Tropical Timber 94, Wetlands
Signed, but not ratified: Marine Life Conservation
Existing and proposed dams, barrages and canals for flood control, irrigation and hydroelectric generation
Geography - note
Landlocked; strategic location between China and India; contains eight of world's 10 highest peaks
[edit] See also
Nepal
List of mountains in Nepal
[edit] References
^ Dahal
This article incorporates public domain material from websites or documents of the Library of Congress Country Studies.
This article incorporates public domain material from the CIA World Factbook document "2005 edition".



[edit] External links
Nepal Encyclopedia Geopolitical category
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koshi (sorrow of bihar)

This article may require copy editing for grammar, style, cohesion, tone or spelling. You can assist by editing it. (August 2008)
Koshi River
River
Countries China, Nepal, India
State Bihar

Cities Biratnagar, Purnia, Katihar

The Kosi River -- called Koshi in Nepal (Nepali: कोशी नदी) as well as Saptakoshi for its seven Himalayan tributaries -- is a transboundary river between Nepal and India, one of the largest tributaries of the Ganges.

The river, along with its tributaries, drains a total area of 69,300 km2 (26,800 sq mi) up to its confluence with the Ganges in India (29,400 km2/11,400 sq mi in China, 30,700 km2/11,900 sq mi in Nepal and 9,200 km2/3,600 sq mi in India). The watershed also includes part of Tibet, including the Mount Everest region, and the eastern third of Nepal.

The river basin is surrounded by the ridges separating it from the Yarlung Zangbo River in the north, the Gandaki in the west, the Mahananda in the east, and by the Ganges in the south. The river is joined by major tributaries in the Mahabharat Range approximately 48 km (30 mi) north of the Indo-Nepal border. Below the outermost foothills (Siwaliks) the river has built up a megafan some 15,000 sq. km in extent, breaking into more than twelve distinct channels with shifting courses due to flooding.[1][2] Kamlā, Bāghmati (Kareh) and Budhi Gandak are major tributaries of Koshi in India, besides minor tributaries like Bhutahi Balān.[3][4] Over the last 250 years, the Kosi River has shifted its course over 120 kilometres (75 mi) from east to west.[5] and the unstable nature of the river is attributed to the heavy silt which it carries during the monsoon season. Flooding in India has extreme effects. India is second in the world after Bangladesh in deaths due to flooding, accounting for one fifth of global flooding deaths. The Kosi River (The Sorrow of Bihar) is one of two major tributaries, the other river being Gandak, draining the plains of north Bihar, the most flood-prone area of India[6]
Kanchenjunga. It has seven major tributaries: the Sun Koshi, the Tama Koshi or Tamba Koshi, the Dudh Koshi, the Indravati, the Likhu River, the Arun and the Tamur. The Dudh Koshi joins the Sun Koshi at the Nepalese village of Harkapur. At Triveni Sun the Koshi is joined by the Arun and the Tamar, after which the river is called the Sapta Koshi. At Barāhkṣetra in Nepal, it descends from the mountains and it is then called simply the Koshi. These tributaries encircle Mt Everest from all sides and are fed by the world's highest glaciers. Further down the Triveni, the river cuts a deep gorge across the lesser Himalayan range of Mahabharat Lekh in a length of 10 km (6.2 mi) and debouches into the plains near Chatra. After flowing for another 58 km (36 mi), it enters the north Bihar plains near Bhimnagar and after another 260 km (160 mi), flows into the Ganges near Kursela(1). The river travels a distance of 729 km (453 mi) from its source to the confluence with the Ganges.

The Kosi river fan located in the northern part of India (in northeast Bihar and eastern Mithila) is one of the largest alluvial cones built by any river in the world. This 180 km (110 mi)-long and 150 km (93 mi)-wide alluvial cone shows evidence of lateral channel shifting exceeding 120 km (75 mi) during the past 250 years through more than 12 distinct channels. The river, which used to flow near Purnea in the 18th century, now flows west of Saharsa (1). The Kosi alluvial cone and its adjoining area have been studied in detail by remote sensing techniques. The data have been integrated with the available geological and geophysical information to decipher the causes responsible for the lateral shift of such a high-magnitude fan. A satellite image shows the old palaeo-channels of the Koshi river with its former (before 1731) confluence with the Mahananda River north of Lava.[7]

mahendra cave nepal

Mahendra Cave is one of the most prominent Tourist Attractions in Pokhara. Pokhara is a major city in Nepal that is located between the Greater Himalaya and Mahabharata Range. This enthralling city of Pokhara is set amidst the tranquil and serene valley, which is the gateway to the world of excitement, natural beauty and adventure. The Mahendra Cave is one site that adds to the charm of the city. You can site the Mahendra Cave at Batulechaur. It will take you just about ten minutes drive from the central market place of the city. As the name of the cave suggests, it has been named after the Late King Mahendra Bir Bikram Shah Dev. Over the years, this has become one of the most visited tourist spots in Pokhara.

It is interesting to note that Mahendra Cave in Pokhara is a natural tunnel that is illuminated artificially. It is recommended to take a torch or light with you for your safety inside the cave. This cave is internationally famous for its rich rock varieties. These rocks are said to sparkle when lights strike on it. Here, you can find big boulders of rocks that are used to block several opening of the caves. Several stalactites in the cave create an eerie effect among the travelers.

caves

A cave or cavern is a natural underground space large enough for a human to enter. Some people suggest that the term cave should only apply to cavities that have some part that does not receive daylight; however, in popular usage, the term includes smaller spaces like sea caves, rock shelters, and grottos.

Speleology is the science of exploration and study of all aspects of caves and the environment which surrounds the caves. Exploring a cave for recreation or science may be called caving, potholing, or, in Canada and the United States, spelunking (see Caving).

[edit] Geographic distribution
Caves are found throughout the world, but only a portion of them have been explored and documented by cavers. The distribution of documented cave systems is widely skewed toward countries where caving has been popular for many years (such as France, Italy, Australia, the UK, the United States, etc.). As a result, explored caves are found widely in Europe, Asia, North America, and Oceania but are sparse in South America, Africa, and Antarctica. This is a great generalization, as large expanses of North America and Asia contain no documented caves, whereas areas such as the Madagascar dry deciduous forests and parts of Brazil contain many documented caves. As the world’s expanses of soluble bedrock are researched by cavers, the distribution of documented caves is likely to shift. For example, China, despite containing around half the world's exposed limestone - more than 1,000,000 square kilometers (390,000 sq mi) - has relatively few documented caves
[edit] Primary cave

Exploring a lava tube in Hawaii.Some caves are formed at the same time as the surrounding rock. These are sometimes called primary caves.

Lava tubes are formed through volcanic activity and are the most common 'primary' caves. The lava flows downhill and the surface cools and solidifies. The hotter lava continues to flow under that crust, and if most of the liquid lava beneath the crust flows out, a hollow tube remains, thus forming a cavity. Examples of such caves can be found on the Canary Islands, Hawaii, and many other places. Kazumura Cave near Hilo is a remarkably long and deep lava tube; it is 65.6 kilometers (40.8 mi) long.

Lava caves, include but are not limited to lava tubes. Other caves formed through volcanic activity include rift caves, lava mold caves, open vertical volcanic conduits, and inflationary caves.

[edit] Sea cave or littoral cave
Main article: Sea cave

Painted Cave, a large sea cave, Santa Cruz Island, CaliforniaSea caves are found along coasts around the world. A special case is littoral caves, which are formed by wave action in zones of weakness in sea cliffs. Often these weaknesses are faults, but they may also be dykes or bedding-plane contacts. Some wave-cut caves are now above sea level because of later uplift. Elsewhere, in places such as Thailand's Phang Nga Bay, solutional caves have been flooded by the sea and are now subject to littoral erosion. Sea caves are generally around 5 meters (16 ft) to 50 meters (160 ft) in length but may exceed 300 meters (980 ft).

[edit] Corrasional cave or erosional cave
Corrasional or erosional caves are those that form entirely by erosion by flowing streams carrying rocks and other sediments. These can form in any type of rock, including hard rocks such as granite. Generally there must be some zone of weakness to guide the water, such as a fault or joint. A subtype of the erosional cave is the wind or aeolian cave, carved by wind-born sediments. Note that many caves formed initially by solutional processes often undergo a subsequent phase of erosional or vadose enlargement where active streams or rivers pass through them.

[edit] Glacier cave
Main article: Glacier cave

Glacier cave in Big Four Glacier, Big Four Mountain, Washington, ca. 1920.Glacier caves occur in ice and under glaciers and are formed by melting. They are also influenced by the very slow flow of the ice, which tends to close the caves again. (These are sometimes called ice caves, though this term is properly reserved for caves that contain year-round ice formations).

[edit] Fracture cave
Fracture caves are formed when layers of more soluble minerals, such as gypsum, dissolve out from between layers of less soluble rock. These rocks fracture and collapse in blocks of stone.

[edit] Talus cave
Talus caves are the openings between rocks that have fallen down into a pile, often at the bases of cliffs (called "talus").

[edit] Anchihaline cave
Main article: Anchihaline cave
Anchihaline caves are caves, usually coastal, containing a mixture of freshwater and saline water (usually sea water). They occur in many parts of the world, and often contain highly specialized and endemic faunas.

deeepest valley

Owens Valley is the arid valley of the Owens River in eastern California in the United States, to the east of the Sierra Nevada. The mountains on either side (including Mount Whitney) reach above 14,000 feet (4,300 m) in elevation, while the floor of the Owens Valley is at 4,000 feet (1,200 m), making the valley one of the deepest in the United States.[2] The Sierra Nevada casts the valley in a rain shadow, which makes Owens Valley "the land of little rain."[3] The bed of Owens Lake, now a dry alkali flat, sits on the southern end of the valley.

The valley provides water to the Los Angeles Aqueduct, the source of one-third of the water for Los Angeles, and is infamous as the scene of one of the fiercest and longest running episodes of the California Water Wars. These episodes inspired aspects of the film Chinatown.

Towns in the Owens Valley include Bishop, Lone Pine, Independence and Big Pine. The major road in the valley is U.S. Route 395.
Beginning about 3 million years ago, the Sierra Nevada Fault and the White Mountains Fault systems became active with repeated episodes of slip earthquakes gradually producing the impressive relief of the eastern Sierra Nevada and White Mountain escarpments that bound the northern Owens Valley-Mono Basin region.

Owens Valley is a graben; a downdropped block of land between two vertical faults. Owens Valley is the westernmost graben in the Basin and Range Province. It is also part of a trough which extends from Oregon to Death Valley called the Walker Lane.[4]

The western flank of much of the valley has large moraines coming off the Sierra Nevada. These unsorted piles of rock, boulders, and dust were bulldozed to where they are by glaciers during the last ice age. An excellent example of a moraine is on State Route 168 as it climbs into Buttermilk Country.[4]

This graben was formed by a long series of earthquakes, such as the 1872 Lone Pine earthquake, that have moved the graben down and helped move the Sierra Nevada up. The graben is in fact much larger than the depth of the valley suggests; gravity studies suggest that 10,000 feet (3,048.0 m) of sedimentary rock mostly fills the graben and that a very steep escarpment is buried under the western length of the valley. The topmost part of this escarpment is exposed at Alabama Hills.

See also: Inyo and Mono Craters. Smaller versions of the Devils Postpile, can be found, for example, by Little Lake.

death valley

Death Valley National Park is a National Park located east of the Sierra Nevada in the arid Great Basin of the United States. Parts of the park are in southern Inyo County and northern San Bernardino County in Eastern California, with a small extension into southwestern Nye County and extreme southern Esmeralda County in Nevada. In addition, there is an exclave (Devil's Hole) in southern Nye County. The park covers 5,262 square miles (13,630 km2), encompassing Saline Valley, a large part of Panamint Valley, almost all of Death Valley, and parts of several mountain ranges.[1] Death Valley National Monument was declared a U.S. National Monument in 1933, placing the area under federal protection. In 1994, the monument was redesignated a national park, as well as being substantially expanded to include Saline and Eureka valleys.[1]

It is the hottest and driest of the national parks in the United States. The second-lowest point in the Western Hemisphere is in Badwater Basin, which is 282 feet (86 m) below sea level. The park is home to many species of plants and animals that have adapted to this harsh desert environment. Some examples include creosote bush, Bighorn Sheep, Coyote, and the Death Valley Pupfish, a survivor of much wetter times. Approximately 95% of the park is designated as wilderness.[2] Its wilderness area covers 4,774 square miles (12,360 km2), making it the largest in the Lower 48 states, and the sixth largest in the United States overall. Death Valley National Park is visited annually by more than 770,000 visitors who come to see its diverse geologic features, desert wildlife, historic sites, scenery, and clear night skies.[3]

Mining was the primary activity in the area before it was protected. The first documented non-Native Americans to enter Death Valley did so in the winter of 1849, thinking they would save time by taking a shortcut to the gold fields of California. They were stuck for weeks and in the process gave the valley its name, even though only one of their group died there. Several short-lived boom towns sprang up during the late 19th and early 20th centuries to exploit minor local bonanzas of gold. The only long-term profitable ore to be mined, however, was borax, a mineral used to make soap and an important industrial compound. Today, borax is an essential component of high-temperature resistant boro-silicate glass products, for example Pyrex cookware. Twenty-mule teams were used to transport ore out of the valley; helping to make it famous and the subject of books, radio programs, television series, and movies.

The natural environment of the area has been shaped largely by its geology. The valley itself is actually a graben. The oldest rocks are extensively metamorphosed and at least 1.7 billion years old.[4] Ancient warm, shallow seas deposited marine sediments until rifting opened the Pacific Ocean. Additional sedimentation occurred until a subduction zone formed off the coast. This uplifted the region out of the sea and created a line of volcanoes. Later the crust started to pull apart, creating the current Basin and Range landform. Valleys filled with sediment and, during the wet times of glacial periods, with lakes, such as Lake Manly.

The park has a diverse and complex geologic history. Since its formation, the area that comprises the park has experienced at least four major periods of extensive volcanism, three or four periods of major sedimentation, and several intervals of major tectonic deformation where the crust has been reshaped. Two periods of glaciation (a series of ice ages) have also had effects on the area, although no glaciers ever existed in the ranges now in the park.

[edit] Basement and Pahrump Group
Little is known about the history of the oldest exposed rocks in the area due to extensive metamorphism (alteration of rock by heat and pressure). Radiometric dating gives an age of 1,700 million years for the metamorphism (during the Proterozoic: See bottom of the geologic timeline).[4] About 1,400 million years ago a mass of granite now in the Panamint Range intruded this complex.[24] Uplift later exposed these rocks to nearly 500 million years of erosion.[24]

On these basement rocks was deposited the sedimentary formation of the Pahrump Group. This occurred after uplift-associated erosion removed whatever rocks covered the Proterozoic-aged rocks. The Pahrump is composed of arkose conglomerate (quartz clasts in a concrete-like matrix) and mud stone in its lower part, followed by dolomite from carbonate banks topped by algal mats in stromatolites, and finished with basin-filling sediment derived from the above, including possible glacial till from the hypothesized Snowball Earth glaciation.[25] The very youngest rocks in the Pahrump Group are from basaltic lava flows.

antartica

For other uses, see Antarctica (disambiguation).
Antarctica


This map uses an orthographic projection, near-polar aspect. The South Pole is near the center, where longitudinal lines converge.

Area (Overall)

(ice-free)

(ice-covered)
14,000,000 km2 (5,400,000 sq mi)[1]
280,000 km2 (100,000 sq mi)
13,720,000 km2 (5,300,000 sq mi)
Population
(permanent)
(non-permanent) 7th
0
approx. 1,000
Dependencies 4[show]
· Bouvet Island
· French Southern Territories
· Heard Island and McDonald Islands
· South Georgia and the South Sandwich Islands
Official Territorial lands Antarctic Treaty System
8[show]
· Adelie Land
· Antártica
· Argentine Antarctica
· Australian Antarctic Territory
· British Antarctic Territory
· Queen Maud Land
· Peter I Island
· Ross Dependency
Unofficial Territorial claims 1[show]
Brazilian Antarctica
Reserved the right to make claims 2[show]
· Russian Federation
· United States of America
Time Zones None
UTC-3 (Graham Land only)
Internet Top-level domain .aq
Calling Code Dependent on the parent country of each base (one such is +672).

Adelie Penguin chicks in Antarctica, with MS Explorer and an iceberg in the background.Antarctica (pronounced /ænˈtɑrktɪkə/ ( listen)) is Earth's southernmost continent, underlying the South Pole. It is situated in the Antarctic region of the southern hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean. At 14.0 million km2 (5.4 million sq mi), it is the fifth-largest continent in area after Asia, Africa, North America, and South America. About 98% of Antarctica is covered by ice, which averages at least 1.6 kilometres (1.0 mi) in thickness.

Antarctica, on average, is the coldest, driest, and windiest continent, and has the highest average elevation of all the continents.[2] Antarctica is considered a desert, with annual precipitation of only 200 mm (8 inches) along the coast and far less inland.[3] There are no permanent human residents but anywhere from 1,000 to 5,000 people reside throughout the year at the research stations scattered across the continent. Only cold-adapted plants and animals survive there, including penguins, seals, nematodes, Tardigrades, mites, many types of algae and other microorganisms, and tundra vegetation.

Although myths and speculation about a Terra Australis ("Southern Land") date back to antiquity, the first confirmed sighting of the continent is commonly accepted to have occurred in 1820 by the Russian expedition of Mikhail Lazarev and Fabian Gottlieb von Bellingshausen. The continent, however, remained largely neglected for the rest of the 19th century because of its hostile environment, lack of resources, and isolation. The first formal use of the name "Antarctica" as a continental name in the 1890s is attributed to the Scottish cartographer John George Bartholomew. The name Antarctica is the romanized version of the Greek compound word ανταρκτική (antarktiké), feminine of ανταρκτικός (antarktikos),[4] meaning "opposite to the north".[5]

The Antarctic Treaty was signed in 1959 by twelve countries; to date, forty-six countries have signed the treaty. The treaty prohibits military activities and mineral mining, supports scientific research, and protects the continent's ecozone. Ongoing experiments are conducted by more than 4,000 scientists of many nationalities and with different research interests.[1]
Centered asymmetrically around the South Pole and largely south of the Antarctic Circle, Antarctica is the southernmost continent and is surrounded by the Southern Ocean; alternatively, it may be considered to be surrounded by the southern Pacific, Atlantic, and Indian Oceans, or by the southern waters of the World Ocean. It covers more than 14,000,000 km2 (5,400,000 sq mi), making it the fifth-largest continent, about 1.3 times as large as Europe. The coastline measures 17,968 km (11,165 mi) and is mostly characterized by ice formations, as the following table shows:

Coastal types around Antarctica (Drewry, 1983) Type Frequency
Ice shelf (floating ice front) 44%
Ice walls (resting on ground) 38%
Ice stream/outlet glacier (ice front or ice wall) 13%
Rock 5%
Total 100%

Maritime AntarcticaAntarctica is divided in two by the Transantarctic Mountains close to the neck between the Ross Sea and the Weddell Sea. The portion west of the Weddell Sea and east of the Ross Sea is called West Antarctica and the remainder East Antarctica, because they roughly correspond to the Western and Eastern Hemispheres relative to the Greenwich meridian.

About 98% of Antarctica is covered by the Antarctic ice sheet, a sheet of ice averaging at least 1.6 km (1.0 mi) thick. The continent has about 90% of the world's ice (and thereby about 70% of the world's fresh water). If all of this ice were melted, sea levels would rise about 60 m (200 ft).[19] In most of the interior of the continent, precipitation is very low, down to 20 mm (0.8 in) per year; in a few "blue ice" areas precipitation is lower than mass loss by sublimation and so the local mass balance is negative. In the dry valleys the same effect occurs over a rock base, leading to a desiccated landscape.

West Antarctica is covered by the West Antarctic Ice Sheet. The sheet has been of recent concern because of the real, if small, possibility of its collapse. If the sheet were to break down, ocean levels would rise by several metres in a relatively geologically short period of time, perhaps a matter of centuries. Several Antarctic ice streams, which account for about 10% of the ice sheet, flow to one of the many Antarctic ice shelves.

East Antarctica lies on the Indian Ocean side of the Transantarctic Mountains and comprises Coats Land, Queen Maud Land, Enderby Land, Mac Robertson Land, Wilkes Land and Victoria Land. All but a small portion of this region lies within the Eastern Hemisphere. East Antarctica is largely covered by the East Antarctic Ice Sheet.


Mount Erebus, an active volcano on Ross Island.Vinson Massif, the highest peak in Antarctica at 4,892 m (16,050 ft), is located in the Ellsworth Mountains. Antarctica contains many other mountains, both on the main continent and the surrounding islands. Located on Ross Island, Mount Erebus is the world's southernmost active volcano. Another well-known volcano is found on Deception Island, which is famous for a giant eruption in 1970. Minor eruptions are frequent and lava flow has been observed in recent years. Other dormant volcanoes may potentially be active.[20] In 2004, an underwater volcano was found in the Antarctic Peninsula by American and Canadian researchers. Recent evidence shows this unnamed volcano may be active.[21]

Antarctica is home to more than 70 lakes that lie at the base of the continental ice sheet. Lake Vostok, discovered beneath Russia's Vostok Station in 1996, is the largest of these subglacial lakes. It was once believed that the lake had been sealed off for 500,000 to one million years but a recent survey suggests that, every so often, there are large flows of water from one lake to another.[22]

There is some evidence, in the form of ice cores drilled to about 400 m (1,300 ft) above the water line, that Lake Vostok's waters may contain microbial life. The frozen surface of the lake shares similarities with Jupiter's moon Europa. If life is discovered in Lake Vostok, this would strengthen the argument for the possibility of life on Europa.[23] On 7 February 2008, a NASA team embarked on a mission to Lake Untersee, searching for extremophiles in its highly alkaline waters. If found, these resilient creatures could further bolster the argument for extraterrestrial life in extremely cold, methane-rich environments.[24]

africa

Africa is the world's second-largest and second most-populous continent, after Asia. At about 30.2 million km² (11.7 million sq mi) including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area.[2] With a billion people (as of 2009, see table) in 61 territories, it accounts for about 14.72% of the World's human population. The continent is surrounded by the Mediterranean Sea to the north, both the Suez Canal and the Red Sea along the Sinai Peninsula to the northeast, the Indian Ocean to the southeast, and the Atlantic Ocean to the west. The continent has 54 states, including Madagascar, various island groups, and the Sahrawi Arab Democratic Republic, a member state of the African Union whose statehood is disputed by Morocco.

Africa, particularly central eastern Africa, is widely regarded within the scientific community to be the origin of humans and the Hominidae clade (great apes), as evidenced by the discovery of the earliest hominids and their ancestors, as well as later ones that have been dated to around seven million years ago – including Sahelanthropus tchadensis, Australopithecus africanus, A. afarensis, Homo erectus, H. habilis and H. ergaster – with the earliest Homo sapiens (modern human) found in Ethiopia being dated to ca. 200,000 years ago.[3]

Africa straddles the equator and encompasses numerous climate areas; it is the only continent to stretch from the northern temperate to southern temperate zones.[4]
Africa is the largest of the three great southward projections from the largest landmass of the Earth. Separated from Europe by the Mediterranean Sea, it is joined to Asia at its northeast extremity by the Isthmus of Suez (transected by the Suez Canal), 163 km (101 miles) wide.[46] (Geopolitically, Egypt's Sinai Peninsula east of the Suez Canal is often considered part of Africa, as well.)[47] From the most northerly point, Ras ben Sakka in Tunisia (37°21' N), to the most southerly point, Cape Agulhas in South Africa (34°51'15" S), is a distance of approximately 8,000 km (5,000 miles);[48] from Cape Verde, 17°33'22" W, the westernmost point, to Ras Hafun in Somalia, 51°27'52" E, the most easterly projection, is a distance of approximately 7,400 km (4,600 miles).[49] The coastline is 26,000 km (16,100 miles) long, and the absence of deep indentations of the shore is illustrated by the fact that Europe, which covers only 10,400,000 km² (4,010,000 square miles) – about a third of the surface of Africa – has a coastline of 32,000 km (19,800 miles).[49]

Africa's largest country is Sudan, and its smallest country is the Seychelles, an archipelago off the east coast.[50] The smallest nation on the continental mainland is The Gambia.


Biomes of Africa (see world vegetation map for key)According to the ancient Romans, Africa lay to the west of Egypt, while "Asia" was used to refer to Anatolia and lands to the east. A definite line was drawn between the two continents by the geographer Ptolemy (85–165 AD), indicating Alexandria along the Prime Meridian and making the isthmus of Suez and the Red Sea the boundary between Asia and Africa. As Europeans came to understand the real extent of the continent, the idea of Africa expanded with their knowledge.

Geologically, Africa includes the Arabian Peninsula; the Zagros Mountains of Iran and the Anatolian Plateau of Turkey mark where the African Plate collided with Eurasia. The Afrotropic ecozone and the Saharo-Arabian desert to its north unite the region biogeographically, and the Afro-Asiatic language family unites the north linguistically.

Climate
The climate of Africa ranges from tropical to subarctic on its highest peaks. Its northern half is primarily desert or arid, while its central and southern areas contain both savanna plains and very dense jungle (rainforest) regions. In between, there is a convergence where vegetation patterns such as sahel, and steppe dominate.

south pole

The South Pole, also known as the Geographic South Pole or Terrestrial South Pole, is one of the two points where the Earth's axis of rotation intersects its surface. It is the southernmost point on the surface of the Earth and lies on the opposite side of the Earth from the North Pole. Situated on the continent of Antarctica, it is the site of the United States Amundsen-Scott South Pole Station, which was established in 1956 and has been permanently staffed since that year. The Geographic South Pole should not be confused with the South Magnetic Pole.

Contents [hide]
1 Geography
1.1 Ceremonial South Pole
2 Exploration
2.1 Pre-1900
2.2 1900–1950
2.3 1950–present
3 Territorial claims
4 Climate, and day and night
5 Time
6 Flora and fauna
7 See also
8 References
9 External links


[edit] Geography

The Geographic South Pole
The Ceremonial South PoleFor most purposes, the Geographic South Pole is defined as the southern point of the two points where the Earth's axis of rotation intersects its surface (the other being the Geographic North Pole). However, the Earth's axis of rotation is actually subject to very small 'wobbles', so this definition is not adequate for very precise work; see Geographic North Pole for further information.

The geographic coordinates of the South Pole are usually given simply as 90°S, since its longitude is geometrically undefined and irrelevant. When a longitude is desired, it may be given as 0°W. At the South Pole all directions face north. For this reason, directions at the Pole are given relative to "grid north", which points northwards along the prime meridian.[1]

The Geographic South Pole is located on the continent of Antarctica (although this has not been the case for all of Earth's history because of continental drift). It sits atop a featureless, windswept, icy plateau at an altitude of 2,835 meters (9,306 ft), about 1,300 km (800 mi) from the nearest sea at McMurdo Sound. The ice is estimated to be about 2,700 meters (9,000 ft) thick at the Pole, so the land surface under the ice sheet is actually near sea level.[2]

The polar ice sheet is moving at a rate of roughly 10 meters per year in a direction between 37° and 40° west of grid north,[3] down towards the Weddell Sea. Therefore, the position of the station and other artificial features relative to the geographic pole gradually shifts over time.

The Geographic South Pole is marked by a small sign and a stake in the ice pack, which are repositioned each year on New Year's Day to compensate for the movement of the ice.[4] The sign records the respective dates that Roald Amundsen and Robert F. Scott reached the Pole, followed by a short quotation from each man and gives the elevation as 2,835 m (9,301 ft).[5]

north pole

The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is, subject to the caveats explained below, defined as the point in the northern hemisphere where the Earth's axis of rotation meets the Earth's surface. It should not be confused with the North Magnetic Pole.

The North Pole is the northernmost point on Earth, lying diametrically opposite the South Pole. It defines geodetic latitude 90° North, as well as the direction of True North. At the North Pole all directions point south; all lines of longitude converge there, so its longitude can be defined as any degree value.

While the South Pole lies on a continental land mass, the North Pole is located in the middle of the Arctic Ocean amidst waters that are almost permanently covered with constantly shifting sea ice. This makes it impractical to construct a permanent station at the North Pole (unlike the South Pole). However, the Soviet Union, and later Russia, have constructed a number of manned drifting stations, some of which have passed over or very close to the Pole. In recent years, a number of studies have predicted that the North Pole may become seasonally ice-free due to Arctic shrinkage, with timescales varying from a few years to fifty years or more.

The sea depth at the North Pole has been measured at 4,261 metres (13,980 ft).[1] The nearest land is usually said to be Kaffeklubben Island, off the northern coast of Greenland about 700 km (440 mi) away, though some perhaps non-permanent gravel banks lie slightly further north.

sahara desert

The Sahara (Arabic: الصحراء الكبرى‎, aṣ-ṣaḥrā´ al-kubra, "The Greatest Desert") is the world's largest non-arctic desert, and technically the world's third largest desert. At over 9,000,000 square kilometres (3,500,000 sq mi), it covers most of Northern Africa, making it almost as large as the United States or the continent of Europe. The desert stretches from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean. To the south, it is delimited by the Sahel: a belt of semi-arid tropical savanna that comprises the northern region of central and western Sub-Saharan Africa.

The Sahara has an intermittent history that may go back as much as 3 million years.[1] Some of the sand dunes can reach 180 metres (590 ft) in height.[2] The name comes from the Arabic word for desert: (صَحراء), "ṣaḥrā´" ( صحراء (help·info); [sˤɑħrɑːʔ]).[3][4]

Contents [hide]
1 Overview
2 Geography
3 Climate history
3.1 Snow and ice
4 Ecoregions
5 Fauna
6 History
6.1 Berbers
6.2 Egyptians
6.3 Nubians
6.4 Phoenicians
6.5 Greeks
6.6 Urban civilization
6.7 Trans-Saharan trade
6.8 European imperialism
6.9 Modern times
7 Peoples and languages
8 See also
9 References
9.1 Notes
9.2 Bibliography
10 External links


[edit] Overview
The Sahara's boundaries are the Atlantic Ocean on the west, the Atlas Mountains and the Mediterranean Sea on the north, the Red Sea and Egypt on the east, and the Sudan and the valley of the Niger River on the south. The Sahara is divided into western Sahara, the central Ahaggar Mountains, the Tibesti Mountains, the Aïr Mountains (a region of desert mountains and high plateaus), Ténéré desert and the Libyan desert (the most arid region). The highest peak in the Sahara is Emi Koussi (3,415 m/11,204 ft) in the Tibesti Mountains in northern Chad.

The Sahara divides the continent of Africa into North and Sub-Saharan Africa. The southern border of the Sahara is marked by a band of semiarid savanna called the Sahel; south of the Sahel lies the lusher Sudan and the Congo River Basin. Most of the Sahara consists of rocky hamada; ergs (large sand dunes) form only a minor part.

People lived on the edge of the desert thousands of years ago[5] since the last ice age. The Sahara was then a much wetter place than it is today. Over 30,000 petroglyphs of river animals such as crocodiles [6] survive, with half found in the Tassili n'Ajjer in southeast Algeria. Fossils of dinosaurs, including Afrovenator, Jobaria and Ouranosaurus, have also been found here. The modern Sahara, though, is not lush in vegetation, except in the Nile Valley, at a few oases, and in the northern highlands, where Mediterranean plants such as the olive tree are found to grow. The region has been this way since about 5000 years ago. Some 2.5 million people currently live in the Sahara, most of these in Egypt, Mauritania, Morocco and Algeria. Dominant ethnicities in the Sahara are various Berber groups including Tuareg tribes, various Arabised Berber groups such as the Hassaniya-speaking Maure (Moors, also known as Sahrawis), and various black African ethnicities including Toubou, Nubians, Zaghawa, Kanuri, Peul (Fulani), Hausa and Songhai. Important cities located in the Sahara include Nouakchott (the capital of Mauritania), Tamanrasset, Ouargla, Bechar, Hassi Messaoud, Ghardaia, and El Oued (Algeria), Timbuktu (Mali), Agadez (Niger), Ghat (Libya), as well as Faya-Largeau (Chad).

[edit] Geography

A geographical map of Africa, showing the ecological break that defines the Saharan areaThe Sahara covers large parts of Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Western Sahara, Sudan and Tunisia. It is one of three distinct physiographic provinces of the African massive physiographic division.

The desert landforms of the Sahara are shaped by wind (eolian) or by occasional rains, and include sand dunes and dune fields or sand seas (erg), stone plateaus (hamada), gravel plains (reg), dry valleys (wadi), and salt flats (shatt or chott).[7] Unusual landforms include the Richat Structure in Mauritania.

Several deeply dissected mountains and mountain ranges, many volcanic, rise from the desert, including the Aïr Mountains, Ahaggar Mountains, Saharan Atlas, Tibesti Mountains, Adrar des Iforas, and the Red Sea hills. The highest peak in the Sahara is Emi Koussi, a shield volcano in the Tibesti range of northern Chad.

Most of the rivers and streams in the Sahara are seasonal or intermittent, the chief exception being the Nile River, which crosses the desert from its origins in central Africa to empty into the Mediterranean. Underground aquifers sometimes reach the surface, forming oases, including the Bahariya, Ghardaïa, Timimoun, Kufrah, and Siwah.

The central part of the Sahara is hyper-arid, with little vegetation. The northern and southern reaches of the desert, along with the highlands, have areas of sparse grassland and desert shrub, with trees and taller shrubs in wadis where moisture collects.

To the north, the Sahara reaches to the Mediterranean Sea in Egypt and portions of Libya, but in Cyrenaica and the Magreb, the Sahara borders Mediterranean forest, woodland, and scrub ecoregions of northern Africa, which have a Mediterranean climate characterized by a winter rainy season. According to the botanical criteria of Frank White[8] and geographer Robert Capot-Rey,[9][10] the northern limit of the Sahara corresponds to the northern limit of Date Palm cultivation (Phoenix dactylifera), and the southern limit of Esparto (Stipa tenacissima), a grass typical of the Mediterranean climate portion of the Maghreb and Iberia. The northern limit also corresponds to the 100 mm (3.9 in) isohyet of annual precipitation.[11]

To the south, the Sahara is bounded by the Sahel, a belt of dry tropical savanna with a summer rainy season that extends across Africa from east to west. The southern limit of the Sahara is indicated botanically by the southern limit of Cornulaca monacantha (a drought-tolerant member of the Chenopodiaceae), or northern limit of Cenchrus biflorus, a grass typical of the Sahel.[9][10] According to climatic criteria, the southern limit of the Sahara corresponds to the 150 mm (5.9 in) isohyet of annual precipitation (note that this is a long-term average, since precipitation varies strongly from one year to another).[11]


An oasis in the Ahaggar Mountains. Oases are crucial to support life in very arid deserts.
An intense Saharan dust storm sent a massive dust plume northwestward over the Atlantic Ocean on March 2, 2003[edit] Climate history
The climate of the Sahara has undergone enormous variation between wet and dry over the last few hundred thousand years.[12] During the last glacial period, the Sahara was even bigger than it is today, extending south beyond its current boundaries.[13] The end of the glacial period brought more rain to the Sahara, from about 8000 BC to 6000 BC, perhaps due to low pressure areas over the collapsing ice sheets to the north.[14]

Once the ice sheets were gone, northern Sahara dried out, But in southern Sahara, the drying trend was soon counteracted by the monsoon, which brought rain further north than it does today. The monsoon is due to heating of air over the land during summer. The hot air rises and pulls in cool, wet air from the ocean, which causes rain. Thus, though it seems counterintuitive, the Sahara was wetter when it received more insolation in the summer. This was caused by a stronger tilt in Earth's axis of orbit than today, and perihelion occurred at the end of July.[15]

By around 3400 BC, the monsoon retreated south to approximately where it is today,[16] leading to the gradual desertification of the Sahara.[17] The Sahara is now as dry as it was about 13,000 years ago.[12] These conditions are responsible for what has been called the Sahara pump theory.

The Sahara has one of the harshest climates in the world. The prevailing north-easterly wind often causes the sand to form sand storms and dust devils.[18] Half of the Sahara receives less than 20 mm (0.79 in) of rain per year, and the rest receives up to 10 cm (3.9 in) per year.[19] The rainfall happens very rarely, but when it does it is usually torrential when it occurs after long dry periods, which can last for years.

The southern boundary of the Sahara, as measured by rainfall, was observed to both advance and retreat between 1980 and 1990. As a result of drought in the Sahel, the southern boundary moved south 130 kilometres (81 mi) overall during that period.[20]. Deforestation has also caused the Sahara to advance south in recent years[citation needed], as trees and bushes continue to be used as fuel source.

Recent signals indicate that the Sahara and surrounding regions are greening due to increased rainfall. Satellites show extensive regreening of the Sahel between 1982 and 2002, and in both Eastern and Western Sahara a more than 20 year long trend of increased grazing areas and flourishing trees and shrubs has been observed by climate scientist Stefan Kröpelin.[21]

[edit] Snow and ice
For the only time in recorded weather history, snow fell in the Sahara desert in southern Algeria on February 18, 1979. The storm lasted only half an hour and the snow was gone within hours.

[edit] Ecoregions

The major topographic features of the Saharan region.The Sahara comprises several distinct ecoregions, whose variations in temperature, rainfall, elevation, and soils harbor distinct communities of plants and animals. According to the World Wide Fund for Nature (WWF), the ecoregions of the Sahara include:

Atlantic coastal desert: The coastal desert occupies a narrow strip along the Atlantic coast, where fog generated offshore by the cool Canary Current provides sufficient moisture to sustain a variety of lichens, succulents, and shrubs. It covers 39,900 square kilometers (15,400 square miles) in Western Sahara and Mauritania.[22]
North Saharan steppe and woodlands: This ecoregion lies along the northern desert, next to the Mediterranean forests, woodlands, and scrub ecoregions of the northern Maghreb and Cyrenaica. Winter rains sustain shrublands and dry woodlands that form a transition between the Mediterranean climate regions to the north and the hyper-arid Sahara proper to the south. It covers 1,675,300 square kilometers (646,800 square miles) in Algeria, Egypt, Libya, Mauritania, Morocco, Tunisia, and Western Sahara.[23]
Sahara desert: This ecoregion covers the hyper-arid central portion of the Sahara where rainfall is minimal and sporadic. Vegetation is rare, and this ecoregion consists mostly of sand dunes (erg, chech, raoui), stone plateaus (hamadas), gravel plains (reg), dry valleys (wadis), and salt flats. It covers 4,639,900 square km (1,791,500 square miles) of Algeria, Chad, Egypt, Libya, Mali, Mauritania, Niger, and Sudan.[24]
South Saharan steppe and woodlands: The South Saharan steppe and woodlands occupy a narrow band running east and west between the hyper-arid Sahara and the Sahel savannas to the south. Movements of the equatorial Intertropical Convergence Zone (ITCZ) bring summer rains during July and August which average 100 to 200 mm (3.9 to 7.9 in), but vary greatly from year to year. These rains sustain summer pastures of grasses and herbs, with dry woodlands and shrublands along seasonal watercourses. The ecoregion covers 1,101,700 km2 (425,400 mi2) in Algeria, Chad, Mali, Mauritania, and Sudan.[25]
West Saharan montane xeric woodlands: Several volcanic highlands in the western portion of the Sahara provide a cooler, moister environment that supports Saharo-Mediterranean woodlands and shrublands. The ecoregion covers 258,100 km2 (99,700 mi2), mostly in the Tassili n'Ajjer of Algeria, with smaller enclaves in the Aïr of Niger, the Dhar Adrar of Mauritania, and the Adrar des Iforas of Mali and Algeria.[26]
Tibesti-Jebel Uweinat montane xeric woodlands: The Tibesti and Jebel Uweinat highlands foster higher, more regular rainfall and cooler temperatures, which support woodlands and shrublands of palms, acacias, myrtle, oleander, Tamarix, and several rare and endemic plants. The ecoregion covers 82,200 km2 (31,700 mi2) in the Tibesti of Chad and Libya, and Jebel Uweinat on the border of Egypt, Libya, and Sudan.[27]
Saharan halophytics: Seasonally-flooded saline depressions in the Sahara are home to halophytic, or salt-adapted, plant communities. The Saharan halophytics cover 54,000 km2 (20,800 mi2), including the Qattara and Siwa depressions in northern Egypt, the Tunisian salt lakes of central Tunisia, Chott Melghir in Algeria, and smaller areas of Algeria, Mauritania, and Western Sahara.[28]
Tanezrouft: One of the harshest regions on Earth and the driest in the Sahara, contains no vegetation and very little life.
[edit] Fauna

Shadows of camels with travelers on dunes in TunisiaDromedary camels and goats are the most domesticated animals found in the Sahara. Because of its qualities of endurance and speed, the dromedary is the favorite animal used by nomads.
The Leiurus quinquestriatus (aka deathstalker) scorpion which can be 10 cm (3.9 in) long. Its venom contains large amounts of agitoxin and scyllatoxin and is very dangerous; however, a sting from this scorpion rarely kills a healthy adult.
The monitor lizard. It has been suggested that the occasional habit of varanids to stand on their two hind legs and to appear to "monitor" their surroundings led to the original Arabic name waral ورل, which is translated to English as "monitor".[29]
Sand vipers, which average less than 50 cm (20 in) in length. Many have a pair of horns, one over each eye. Active at night, they usually lie buried in the sand with only their eyes visible. Bites are painful, but rarely fatal.
The African Wild Dog has some populations confirmed[citation needed] in the southern Sahara and is frequently misidentified as the cryptid Adjule.
The fennec fox, pale fox and Rüppell's fox, are omnivorous canids living in many parts of Sahara.
The hyrax. It first appears in the fossil record over 40 million years ago, and for many millions of years hyraxes were the primary terrestrial herbivore in Africa.
The ostrich which is a flightless bird native to Africa. They have become rare.
The addax, a large white antelope, is a threatened species. Adapted to the desert, they can remain months without drinking, even a whole year.
The Saharan cheetah lives in Algeria, Togo, Niger, Mali, Benin, and Burkina Faso. There remain less than 250 mature cheetahs which are very cautious, fleeing any human presence. The cheetah avoids the sun from April to October. It then seeks the shelter of shrubs such as balanites and acacias. They are unusually pale.[30][31]
The dorcas gazelle is a north African gazelle that can also go for a long time without water.
There exist other animals in the Sahara (birds in particular) such as African Silverbill and Black-throated Firefinch among others.

[edit] History

Photo of the Sahara from 1908[edit] Berbers
Berbers are one of the oldest known inhabitants of the Sahara Desert.[citation needed] They are the people that occupied (and still occupy) more than two thirds of the Sahara's total surface.[citation needed]The Garamantes Berbers built a prosperous empire in the heart of the desert.[citation needed] The Tuareg nomads continue, to present day, to inhabit and move across wide Sahara surfaces in Algeria, Mali, Niger, Mauritania, and Libya. Some of the oldest Berber Tifinagh inscriptions are found in Southern Algeria, Northern Mali and Niger.[citation needed]

[edit] Egyptians
By 6000 BC predynastic Egyptians in the southwestern corner of Egypt were herding cattle and constructing large buildings. Subsistence in organized and permanent settlements in predynastic Egypt by the middle of the 6th millennium BC centered predominantly on cereal and animal agriculture: cattle, goats, pigs and sheep. Metal objects replaced prior ones of stone. Tanning of animal skins, pottery and weaving are commonplace in this era also.[32] There are indications of seasonal or only temporary occupation of the Al Fayyum in the 6th millennium BC, with food activities centering on fishing, hunting and food-gathering. Stone arrowheads, knives and scrapers are common.[33] Burial items include pottery, jewelry, farming and hunting equipment, and assorted foods including dried meat and fruit. Burial in desert environments appears to enhance Egyptian preservation rites, and dead are buried facing due west.[32] By 3400 BC, the Sahara was as dry as it is today, and it became a largely impenetrable barrier to humans, with only scattered settlements around the oases, but little trade or commerce through the desert. The one major exception was the Nile Valley. The Nile, however, was impassable at several cataracts, making trade and contact by boat difficult.


A Saharan village in Mali[edit] Nubians
During the Neolithic, before the onset of desertification, around 9500 BC the central Sudan had been a rich environment supporting a large population ranging across what is now barren desert, like the Wadi el-Qa'ab. By the 5th millennium BC, the peoples who inhabited what is now called Nubia, were full participants in the "agricultural revolution," living a settled lifestyle with domesticated plants and animals. Saharan rock art of cattle and herdsmen found suggests the presence of a cattle cult like those found in Sudan and other pastoral societies in Africa today.[34] Megaliths found at Nabta Playa are overt examples of probably the world's first known Archaeoastronomy devices, predating Stonehenge by some 1000 years.[35] This complexity, as observed at Nabta Playa, and as expressed by different levels of authority within the society there, likely formed the basis for the structure of both the Neolithic society at Nabta and the Old Kingdom of Egypt.[36]

[edit] Phoenicians
The peoples of Phoenicia, who flourished between 1200-800 BC, created a confederation of kingdoms across the entire Sahara to Egypt. They generally settled along the Mediterranean coast, as well as the Sahara, among the peoples of Ancient Libya, who were the ancestors of peoples who speak Berber languages in North Africa and the Sahara today, including the Tuareg of the central Sahara.

The Phoenician alphabet seems to have been adopted by the ancient Libyans of north Africa, and Tifinagh is still used today by Berber-speaking Tuareg camel herders of the central Sahara.

Sometime between 633 BC and 530 BC, Hanno the Navigator either established or reinforced Phoenician colonies in Western Sahara, but all ancient remains have vanished with virtually no trace. (See History of Western Sahara.)


An Algerian man in urban dress
The 12th Century traveller Benjamin of Tudela in the Sahara (Dumouza, 19th Century engraving)[edit] Greeks
By 500 BC, a new influence arrived in the form of the Greeks. Greek traders spread along the eastern coast of the desert, establishing trading colonies along the Red Sea coast. The Carthaginians explored the Atlantic coast of the desert. But the turbulence of the waters and the lack of markets never led to an extensive presence further south than modern Morocco. Centralized states thus surrounded the desert on the north and east; it remained outside the control of these states. Raids from the nomadic Berber people of the desert were a constant concern of those living on the edge of the desert.

[edit] Urban civilization
An urban civilization, the Garamantes, arose around this time in the heart of the Sahara, in a valley that is now called the Wadi al-Ajal in Fazzan, Libya.[12] The Garamantes achieved this development by digging tunnels far into the mountains flanking the valley to tap fossil water and bring it to their fields. The Garamantes grew populous and strong, conquering their neighbors and capturing many slaves (which were put to work extending the tunnels). The ancient Greeks and the Romans knew of the Garamantes and regarded them as uncivilized nomads. However, they traded with the Garamantes, and a Roman bath has been found in the Garamantes capital of Garama. Archaeologists have found eight major towns and many other important settlements in the Garamantes territory. The Garamantes civilization eventually collapsed after they had depleted available water in the aquifers, and could no longer sustain the effort to extend the tunnels still further into the mountains.[37]

[edit] Trans-Saharan trade
Main article: Trans-Saharan trade
Following the Islamic conquest of North Africa in the mid-seventh to early eighth centuries, trade across the desert intensified. The kingdoms of the Sahel, especially the Ghana Empire and the later Mali Empire, grew rich and powerful exporting gold and salt to North Africa. The emirates along the Mediterranean Sea sent south manufactured goods and horses. From the Sahara itself, salt was exported. This process turned the scattered oasis communities into trading centres, and brought them under the control of the empires on the edge of the desert. A significant slave trade crossed the desert (See Arab slave trade).

This trade persisted for several centuries until the development in Europe of the caravel allowed ships, first from Portugal but soon from all Western Europe, to sail around the desert and gather the resources from the source in Guinea. The Sahara was rapidly remarginalized.

[edit] European imperialism
At the beginning of the 19th century, most of the northern Sahara, including most of present-day Algeria, Tunisia, Libya, and Egypt, was part of the Ottoman Empire. The Sahel and southern Sahara were home to several independent states.

European colonialism in the Sahara began in the 19th century. France conquered Algeria from the Ottomans in 1830, and French rule spread south from Algeria and eastwards from Senegal into the upper Niger to include present-day Algeria, Chad, Mali, Mauritania, Morocco (1912), Niger, and Tunisia (1881).

Egypt, under Muhammad Ali and his successors, conquered Nubia (1820–22), founded Khartoum (1823), and conquered Darfur (1874). Egypt, including the Sudan, became a British protectorate in 1882. Egypt and Britain lost control of the Sudan from 1882 to 1898 as a result of the Mahdist War. After its capture by British troops in 1898, the Sudan became a Anglo-Egyptian condominium.

Spain captured present-day Western Sahara after 1874. In 1912, Italy captured Libya from the Ottomans.

To promote the Roman Catholic religion in the desert, the Pope in 1868 appointed a delegate Apostolic of the Sahara and the Sudan; later in the 19th century his jurisdiction was reorganized into the Vicariate Apostolic of Sahara.

[edit] Modern times

A natural rock arch in south western LibyaEgypt became independent of Britain in 1936, although the Anglo-Egyptian Treaty of 1936 allowed Britain to keep troops in Egypt and maintained the British-Egyptian condominium in the Sudan. British military forces were withdrawn in 1954.

Most of the Saharan states achieved independence after World War II: Libya in 1951, Morocco, Sudan, and Tunisia in 1956, Chad, Mali, Mauritania, and Niger in 1960, and Algeria in 1962. Spain withdrew from Western Sahara in 1975, and it was partitioned between Mauritania and Morocco. Mauritania withdrew in 1979, but Morocco continues to hold the territory.

The modern era has seen a number of mines and communities develop to exploit the desert's natural resources. These include large deposits of oil and natural gas in Algeria and Libya and large deposits of phosphates in Morocco and Western Sahara.

A number of Trans-African highways have been proposed across the Sahara, including the Cairo-Dakar Highway along the Atlantic coast, the Trans-Sahara Highway from Algiers on the Mediterranean to Kano in Nigeria, the Tripoli-Cape Town Highway from Tripoli in Libya to Ndjamena in Chad, and the Cairo-Cape Town Highway which follows the Nile. Each of these highways is partially complete, with significant gaps and unpaved sections.

[edit] Peoples and languages
The Sahara is home to a number of people and languages. Arabic is the most widely spoken language in the Sahara, from the Atlantic to the Red Sea. Berber people are found from western Egypt to Morocco, including the Tuareg pastoralists of the central Sahara. The Beja live in the Red Sea Hills of southeastern Egypt and eastern Sudan. The Arabic, Berber, and Beja languages are part of the Afro-Asiatic language family.

Speakers of the Nilo-Saharan language family also inhabit the Sahara, including the Fur of Darfur in western Sudan and the Saharan languages of Niger, Chad and western Sudan, which includes the Kanuri, Tedaga, and Dazaga.

machu picchu

Machu Picchu (Quechua: Machu Pikchu, "Old Mountain", pronounced [ˈmɑ.t͡ʃu ˈpix.t͡ʃu]) is a pre-Columbian Inca site located 2,430 metres (7,970 ft) above sea level.[1][2] It is situated on a mountain ridge above the Urubamba Valley in Peru, which is 80 kilometres (50 mi) northwest of Cusco and through which the Urubamba River flows. Most archaeologists believe that Machu Picchu was built as an estate for the Inca emperor Pachacuti (1438–1472). Often referred to as "The Lost City of the Incas", it is perhaps the most familiar icon of the Inca World.

The Incas started building the estate around AD 1400 but it was abandoned as an official site for the Inca rulers a century later at the time of the Spanish conquest of the Inca Empire. Although known locally, it was unknown to the outside world before being brought to international attention in 1911 by the American historian Hiram Bingham. Since then, Machu Picchu has become an important tourist attraction.

Machu Picchu was declared a Peruvian Historical Sanctuary in 1981 and a UNESCO World Heritage Site in 1983.[2] Since it was not plundered by the Spanish when they conquered the Incas, it is especially important as a cultural site and is considered a sacred place. Machu Piccu was named one of the New Seven Wonders of the World through an online and telephone poll conducted by the New7Wonders foundation.

Machu Picchu was built in the classical Inca style, with polished dry-stone walls. Its primary buildings are the Intihuatana, the Temple of the Sun, and the Room of the Three Windows. These are located in what is known by archaeologists as the Sacred District of Machu Picchu. In September 2007, Peru and Yale University reached an agreement regarding the return of artifacts which Hiram Bingham had removed from Machu Picchu in the early twentieth century.

Amazon

Amazon.com, Inc. (NASDAQ: AMZN) is an American-based multinational electronic commerce company. Headquartered in Seattle, Washington, it is America's largest online retailer, with nearly three times the Internet sales revenue of the runner up, Staples, Inc., as of January 2010.[3]

Jeff Bezos founded Amazon.com, Inc. in 1994 and launched it online in 1995. It started as an online bookstore, but soon diversified to product lines of VHS, DVD, music CDs and MP3s, computer software, video games, electronics, apparel, furniture, food, toys, and so on. Amazon has established separate websites in Canada, the United Kingdom, Germany, France, Japan, and China. It also provides international shipping to certain countries for some of its products.

On January 15, 2009, a survey published by Verdict Research found that Amazon was the UK's favorite music and video retailer, and came third in overall retail rankings.[4]

nile(the longest river)

The Nile (Arabic: النيل‎, an-nīl, Ancient Egyptian iteru or Ḥ'pī, Coptic piaro or phiaro) is a major north-flowing river in Africa, generally regarded as the longest river in the world.[1]

The Nile has two major tributaries, the White Nile and Blue Nile, the latter being the source of most of the Nile's water and fertile soil, but the former being the longer of the two. The White Nile rises in the Great Lakes region of central Africa, with the most distant source in southern Rwanda at 2°16′55.92″S 29°19′52.32″E / 2.2822°S 29.3312°E / -2.2822; 29.3312, and flows north from there through Tanzania, Lake Victoria, Uganda and southern Sudan, while the Blue Nile starts at Lake Tana in Ethiopia at 12°2′8.8″N 37°15′53.11″E / 12.035778°N 37.2647528°E / 12.035778; 37.2647528, flowing into Sudan from the southeast. The two rivers meet near the Sudanese capital of Khartoum.

The northern section of the river flows almost entirely through desert, from Sudan into Egypt, a country whose civilization has depended on the river since ancient times. Most of the population and cities of Egypt lie along those parts of the Nile valley north of Aswan, and nearly all the cultural and historical sites of Ancient Egypt are found along the banks of the river. The Nile ends in a large delta that empties into the Mediterranean Sea.

sagarmatha(mt.everst)

Mount Everest – also called Qomolangma Peak (Tibetan: ཇོ་མོ་གླང་མ), Mount Sagarmāthā (Nepali: सगरमाथा), Chajamlungma (Limbu), Zhumulangma Peak (Chinese: 珠穆朗玛峰 Zhūmùlǎngmǎ Fēng) or Mount Chomolungma – is the highest mountain on Earth above sea level, and the highest point on the Earth's continental crust, as measured by the height above sea level of its summit, 8,848 metres (29,029 ft). The mountain, which is part of the Himalaya range in Asia, is located on the border between Sagarmatha Zone, Nepal, and Tibet, China.

In 1856, the Great Trigonometric Survey of India established the first published height of Everest, then known as Peak XV, at 29,002 ft (8,840 m). In 1865, Everest was given its official English name by the Royal Geographical Society upon recommendation of Andrew Waugh, the British Surveyor General of India at the time. Chomolungma had been in common use by Tibetans for centuries, but Waugh was unable to propose an established local name because Nepal and Tibet were closed to foreigners.
Sagarmāthā
ཇོ་མོ་གླང་མ

Everest from Kala Patthar in Nepal
Elevation 8,848 m (29,029 ft) [1]
Ranked 1st
Prominence 8,848 m (29,029 ft) 
Notice special definition for Everest.
Listing Seven Summits
Eight-thousander
Country high point
Ultra

The highest mountain in the world attracts well-experienced mountaineers as well as novice climbers who are willing to pay substantial sums to professional mountain guides to complete a successful climb. The mountain, while not posing substantial technical climbing difficulty on the standard route (other eight-thousanders such as K2 or Nanga Parbat are much more difficult), still has many inherent dangers such as altitude sickness, weather and wind. By the end of the 2008 climbing season, there had been 4,102 ascents to the summit by about 2,700 individuals.[4] Climbers are a significant source of tourist revenue for Nepal, whose government also requires all prospective climbers to obtain an expensive permit, costing up to US $ 25,000 per person.[5] By the end of 2009 Everest had claimed 216 lives,[4] including eight who perished during a 1996 storm high on the mountain. Conditions are so difficult in the death zone that most corpses have been left where they fell. Some of them are visible from standard climbing routes.[6]