Kilimanjaro

Kilimanjaro
Author Selzer-McKenzie
Kilimanjaro with its three volcanic cones, Kibo, Mawenzi, and Shira, is an inactive stratovolcano in north-eastern Tanzania[2] rising 4,600 m (15,100 ft) from its base (and approximately 5,100 m (16,700 ft) from the plains near Moshi), and is additionally the highest peak in Africa at 5,891.8 metres (19,330 ft), providing a dramatic view of the surrounding plains.
he highest point on Kilimanjaro is Uhuru Peak, on the volcano Kibo. Its height value attracted a lot of interest as the reports of the first Europeans to see the mountain reached Europe. Since 1889, several attempts have been made to determine the exact height of the mountain, but the several methods have given varying results and differ by as much as 100 metres.[3] The Kilimanjaro 2008 Precise Height Measurement Expedition used GPS and gravimeter methods to output the value of 5,891.8 metres (19,330 ft).[4] On top of Kibo is a 1.5 mile wide crater. As the highest point in Africa, Uhuru Peak is one of the Seven Summits. The summit was first reached by the Marangu army scout Yohanas Kinyala Lauwo, German Hans Meyer and Austrian Ludwig Purtscheller, on October 6, 1889. Two other peaks are also dormant volcanoes: Mawenzi (5,149 m, 16,890 ft), the third highest peak in Africa (after Mount Kenya) and Shira (3,962 m, 13,000 ft). Yohanas' Notch is named after Lauwo.

Due to Kilimanjaro's equatorial location and high elevation, almost every climate type on earth is represented, including a year-round snow-topped summit.

The summit of Kilimanjaro is covered by a GSM mobile phone network, and was previously the highest point in the world with mobile phone service.
While the volcano appears to be dormant on the inside, events on top of the mountain draw global attention. The top of the mountain has seen a retreat of the most recent covering of glaciers,[5] with the most recent ice cap volume dropping by more than 80%.[6]

Sources disagree when the glaciers will be gone due to melting. In 2002, a study led by Ohio State University ice core paleoclimatologist Lonnie Thompson predicted that ice on top of Africa's tallest peak would be gone between 2015 and 2020.[7][8][9] In 2007, a team of Austrian scientists from University of Innsbruck predicted that the plateau ice cap will be gone by 2040, but some ice on the slope will remain longer due to local weather conditions.[10] Yet, another, the California Academy of Sciences, predicts that the [glaciers] will be gone by 2050.[11] A comparison of ice core records suggests conditions today are returning to those of 11,000 years ago. A study by Philip Mote of the University of Washington in the United States and Georg Kaser of the University of Innsbruck in Austria concludes that the shrinking of Kilimanjaro's ice cap is not directly due to rising temperature but rather to decreased precipitation.[12] In May 2008 The Tanzanian Minister for Natural Resources, Ms Shamsa Mwangunga, said that there were indications that snow cover on the mountain was actually increasing.[13] In January 2006, the Western Breach route was closed by the Tanzanian government following a rockslide that killed four people at Arrow Glacier Camp. On December 1, 2007 the Western Breach route was reopened for climbing.
While it is inactive, Kilimanjaro has fumaroles that emit gas in the crater on the main summit of Kibo. Scientists concluded in 2003 that molten magma is just 400 metres (1,310 ft) below the summit crater. Several collapses and landslides have occurred on Kibo in the past, one creating the area known as the Western Breach.
Mount Kilimanjaro is one of the largest stratovolcanoes in the world. Otherwise known as a composite volcano, it comprises numerous layers of lava, tephra and volcanic ash. Tephra is rhyolitic (an igneous, extrusive rock) in composition, and is formed by air-fall material of an eruption, which suggests the composite volcano was once active. However, at the moment it is dormant. According to experts there have been no eruptions in living memory. Recent studies suggest the last eruptions on the mountain were between 150,000 and 200,000 years ago.[14]

Mount Kilimanjaro is in the shape of a conical volcano; it is formed by ejecta being thrown up by the volcano vent, which then piles around the vent in the shape of a cone. Due to the fact that Mount Kilimanjaro is made up of tephra, it has a cinder cone. This is because the mountains cone is made up of tephra cinders. They are made up of blobs of congealed lava and particles. When the mountain did erupt millions of years ago, the gas-charged lava would be blown violently into the air, then breaking the smaller fragments which would solidify and fall as cinders. This left Mount Kilimanjaro with a bowl-shaped crater. In geologic history, it would not be uncommon for a stratovolcano such as Mount Kilimanjaro to have experienced explosive eruptions. The lava from the mountain is viscous (viscosity is a measure of the thickness of a fluid which is deformed by shear stress or extensional stress) which cools down before it spreads very far. The lava's viscosity helps explain why Mount Kilimanjaro has relatively small crater formations. The rock on the mountain is felsic and has high levels of silica, especially tephratic silicate. This silica is also in alternating sectors, with lava flows and ejecta in different formations. This is called stratum, which is usually formed by natural forces (i.e. volcanic eruptions) from Mount Kilimanjaro.
Relief of Kilimanjaro

The volcano is the highest in Africa and covers an area of 388,500ha. Although the volcano stands alone, it is a part of an east-west belt of volcanoes stretching over Northern Tanzania. It has three main concentric cones to the southeast in the mountain, but also has smaller parasitic cones. Also known as a satellite cone, the main vent is blocked by cooled solidified lava, and the lava is then forced out through the sides of a volcano under immense pressure. To the west side of the mountain is the peak Shira (3,962m), of which only the southern and western rims remain.

In addition to the west there is also a flat tableland. On the edges of this material is later material made by the former eruptions of the mountain, and so it’s a dissected plateau. This is a plateau which has been uplifted by volcanic activity, then been severely eroded, which explains the material around the edge of the plateau. The peak of Mawenzi (5,149m) - which is rugged and erosion-shattered- can be found in the east of the volcano. Its western face has many features: crags, pinnacles and dyke swarms. Crags are a steeped mass of rock projecting upward or outward. Pinnacles are high peaks or points of rock, but in Mount Kilimanjaros case then it’s a high point of rock. A dike (plural dyke swarm) is a type of sheet intrusion that cuts discordantly across. These come in several forms: planar wall rock structures or massive rock formations. On Mawenzi these are formed in igneous intrusions. These form in high aspect ratios, so the thickness is smaller than the other 2 dimensions. The dykes intrude into a cross-cutting fissure. These are linear volcanic vents through which lava erupts, although Mount Kilimanjaro is dormant so it does not happen.

To the eastern side of Mawenzi it falls into cliffs, with a complex system of gullies and rock faces. These rises from two massive gorges: the Great Barranco and Lesser Barranco. Gorges are deep valleys between cliffs that are formed by erosion, and were formed from the plateau that can be found to the eastern side of the mountain. The cliffs form because harder rock strata that are resistant to erosion/weathering remain exposed on the valley walls. The most recent summit is Kibo (5,891.8 m) which was last active during the Pleistocene. There are still even fumaroles. Even though there haven’t been eruptions for millions of years, there are openings near Kobe in the Earth’s crust which emits steam and gases e.g. Carbon Dioxide, Hydrochloric Acid. It even emits solfatara (Sulphurous gases). They occur along the chaotic clusters and long fissures. The hot igneous rocks react with the groundwater, which makes it release gases.

The highest point on the mountain is the southern rim of the outer crater. Moreover, between Kibo and Mawenzi is the Saddle, in which it contains high altitude tundra. This type of vegetation forms at high levels of altitude because tree growth is hindered by low temperatures and short growing seasons. There is a wide range of vegetation despite being at high altitude such as dwarf shrubs, grasses, mosses and lichens. The ecotone (difference between tundra and forest) is called the timberland. On Mount Kilimanjaro there are radial valleys that can be found on the southern and eastern slopes. They are smaller valleys that flank the mountains main valleys.
Kilimanjaro has unique vegetation such as the water holding cabbage in the tussock grassland and other plants like this, all adapted to living in alpine conditions. Kilimanjaro has a large variety of forest types over an altitudinal range of 3000 m containing over 1200 vascular plant species. Montane Ocotea forests occur on the wet southern slope. Cassipourea and Juniperus forests grow on the dry northern slope. Subalpine Erica forests at 4100 m represent the highest elevation cloud forests in Africa. In contrast to this enormous biodiversity, the degree of endemism is low. However, forest relicts in the deepest valleys of the cultivated lower areas suggest that a rich forest flora inhabited Mt Kilimanjaro in the past, with restricted-range species otherwise only known from the Eastern Arc mountains. The low degree of endemism on Kilimanjaro may result from destruction of lower altitude forest rather than the relatively young age of the mountain. Another feature of the forests of Kilimanjaro is the absence of a bamboo zone, which occurs on all other tall mountains in East Africa with a similarly high rainfall. 'Sinarundinaria alpina' stands are favoured by elephants and buffaloes. On Kilimanjaro these megaherbivores occur on the northern slopes, where it is too dry for a large bamboo zone to develop. They are excluded from the wet southern slope forests by topography and humans, who have cultivated the foothills for at least 2000 years. This interplay of biotic and abiotic factors could explain not only the lack of a bamboo zone on Kilimanjaro but also offers possible explanations for the patterns of diversity and endemism. Kilimanjaro's forests can therefore serve as a striking example of the large and long-lasting influence of both animals and humans on the African landscape.