Facts and Details

MOUNTAINS

Shishapangma, world's 14th highest mountain Mountains are often formed where tectonic plates collide and land is pushed upwards or to a lesser extent where magma rises towards the surfaces and causes the ground to swell and bulge or where faults move and crack. New mountains tend be higher than old ones because they have been recently pushed up by these forces. Old mountains are smaller because the forces that built them ended long ago and they have been worn down by millions of years of weathering and erosion. Mountains with craggy peaks, sheer cliffs and spectacular Alpine features are usually that way because they have been carved and chiseled by glaciers and ice. [Source: Mostly from Cliff Notes, USGS and newspaper articles]

Mountain building features include: 1) anticlines, a folds that points upward like an arch. 2) synclines, folds that points downward; 3) geosynclines, large synclines caused when sediments from mountain ranges bend down the crust. Faults can cause the land to rise or fall. Valleys called grabbens often form and fill with sediment.

Mountains are often formed where plates collide and land is pushed upwards or to a lesser extent where magma rises towards the surfaces and causes the ground to swell and bulge or where faults move and crack. New mountains tend be higher than old ones because they have been recently pushed up by these forces. Old mountains are smaller because the forces that built them ended long ago and they have been worn down by millions of years of weathering and erosion. Mountains with craggy peaks, sheer cliffs and spectacular Alpine features are usually that way because they have been carved and chiseled by glaciers and ice.

Mountains result from the application of tectonic forces to rocks, usually sedimentary or volcanic rocks. (These may be changed to metamorphic rocks as mountain-building progresses, and at times metamorphic rocks can be pushed into mountains). Mountain-building on continents is associated with intense deformation, folding, and faulting, usually along convergent plate boundaries. An orogeny, or orogenesis, is the overall process by which a mountain system is built. [Source: CliffsNotes.com. Features of Mountain Belts Cliff Notes Cliff Notes ]

Mountain ranges are groups of mountain peaks or ridges that form discrete topographic areas that are usually bordered by valleys or rivers. It takes tens or hundreds of millions of years to develop mountain belts, long chains of mountain ranges that can extend across continents or along their edges.

The higher you climb the colder it gets. This is because as air rises is expands and therefore cools. On average the temperature drops 1degree F for every 300 feet rise in elevation. Above the freezing line snow falls and may accumulate into glaciers.

Mountains: Summit Climb Summit Climb ; Trekking Tibet Trekking Tibet ; Samrat Nepal Samrat Nepal ; Himalayas Wikipedia article on the Himalayas Wikipedia ; Making of Himalayas geol.unibas ; Himalayas site himalayas.dk ; Mt. Everest : Wikipedia Wikipedia National Geographic National Geographic Mount Everest.net Mont Everest.net Summit Post Summit Post ; Glaciers: All About Glaciers nsidc.org ; Wikipedia article on Glaciers Wikipedia ; Wikipedia article on Avalanches Wikipedia

Features of Mountain Belts

Mountain belts typically are thousands of kilometers long and hundreds of kilometers across and parallel continental coastlines. The American Cordillera is a series of steep mountain ranges that rim the western edge of North and South America; it is one of the longest mountain belts in the world. In general, the taller mountains are geologically younger than lower mountains (for example, the steeper Rocky Mountains are younger than the lower and more rounded Appalachian Mountains) because older ranges have undergone more weathering and erosion. Most mountain ranges are uplifted, erode to low elevations, and are uplifted again before they become stable.[Source: CliffsNotes.com. Features of Mountain Belts, Cliff Notes Cliff Notes ]

Cratons. Billions of years ago the now-stable interior of North America was a mountainous, tectonically active region that eventually stabilized and weathered to a peneplain (an area reduced by erosion nearly to a plain). A continental interior that has been structurally inactive for hundreds of millions of years is called a craton. It is composed of mostly plutonic and metamorphic rocks. The craton is a “basement” upon which sequences of sedimentary rocks were deposited under marine or nonmarine conditions. The central United States is covered by about 2,000 meters of sedimentary rocks that were deposited in shallow Paleozoic oceans. Continents have grown larger through accretionary episodes in which mostly sedimentary material and volcanic arcs were welded to the craton through plate collisions, usually resulting in mountain-building.

Rock types. Mountains are typically composed of folded sedimentary strata that may be up to five times as thick as the original sedimentary sequence that covered the cratonic interior. The folded and broken layers indicate the rock has undergone deformation during mountain-building. Since mountain belts typically form along tectonically active coastlines and above subduction zones, much of the sedimentary rock is marine in origin. The sediments are often parts of the accretionary wedge that have been compressed, folded, and driven onto the continent by plate tectonic processes.

How intensely a mountain belt is folded depends on how great the tectonic forces were. Mountain-building forces are intensely compressional, and the sedimentary sequence in a basin is often squeezed into a mountain range that is less than half the width of the original basin. Rock layers are typically contorted into tight fold patterns, including overturned or recumbent folds. Fold and thrust belts in many mountain ranges are the result of multiple thrust layers (sheets) of rock that have been thrust forward and stacked vertically along the low-angle detachment faults that separate the thrust sheets. After uplift has been completed, a later stage of tensional stress develops that forms a series of fault-block (horst and graben) mountains. The faulting is an adjustment to the extensional stress created by the vertical uplift.

The core of a mountain range tends to be its most intensely metamorphosed part. The metamorphic rocks were originally sedimentary rocks or volcanic rocks that were intensely metamorphosed through deep burial, folding, and tectonic uplift. It is often difficult to recognize the original rock types, and metamorphic rocks are typically mapped as “schist” or “gneiss.” Migmatites are some of the most intensely metamorphosed rocks that are found in the cores of mountain ranges. The large batholithic intrusions that underlie mountain ranges were formed by partial melting during the mountain-building process. The continental crust under mountain ranges is thicker than that under the cratonic interior; similarly, the crust under younger mountain ranges is thicker than the crust under older ranges. The uplift of these blocks of crust eventually stabilizes through isostatic adjustments. Geologically young, tectonically active mountains have more earthquakes and volcanic activity than the older, more stabilized mountain chains.

Types of Mountains

There are four types of mountains: 1) folded mountains, formed by pressure within the Earth that caused uplifting; 2) fault block mountains, formed by shifts along faults; 3) dome mountains, formed by uplift by magma that doesn't break through the surface; and 4) volcanoes.

Although each mountain range has a unique set of characteristics, a particular mountain can be structurally classified as upwarped, volcanic, fault-block (horst and graben), or folded (complex). It is not unusual to find all four categories of mountains within a single mountain range.[Source: CliffsNotes.com. Types of Mountain Belts, Cliff Notes Cliff Notes ]

Upwarped mountains are generally the result of broad arching of the crust or sometimes great vertical displacement along a highangle fault. The Black Hills in South Dakota and the Adirondack Mountains in New York are upwarped mountain ranges. These mountains are more rounded and show some unloading features such as exfoliation. Volcanic mountains are the accumulations of large amounts of volcanic lavas and pyroclastic material around the volcanic vent, such as seamounts and stratovolcanoes. The Hawaiian and Aleutian Islands are volcanic mountains.

Fault-block mountains result from tensional stress. They are bounded by high-angle normal faults, and usually form a series of horsts and grabens. Broad crustal uplift (possibly a result of subduction stresses or mantle upwelling) can stretch and break the crust, creating fault zones along which the blocks move or slide. Uneven tectonic uplift can tilt the blocks. A good example of fault-block mountains are those in Nevada that are part of the Basin and Range region. Folded, or complex, mountains are created by intense compressional forces that fold, fault, and metamorphose the rocks, resulting in many of the world's biggest mountain belts, such as the Himalayas.

How Mountains Form

Mountain building features include: 1) anticlines, a folds that points upward like an arch. 2) synclines, folds that points downward; 3) geosynclines, large synclines caused when sediments from mountain ranges bend down the crust. Faults can cause the land to rise ro fall. Valleys called grabbens often form and fill with sediment.

In general, it takes hundreds of millions of years for mountain belts to form, stabilize, and erode to become part of a stable craton. This evolution is marked by three stages: accumulation, orogeny, and uplift/block-faulting. [Source: CliffsNotes.com. How Mountains Form, Cliff Notes Cliff Notes ]

Accumulation. Many mountains contain sequences of sedimentary and volcanic rocks that reach thicknesses of 2,000 to 3,000 meters. Most of this material was deposited in a passive or active continental marine environment during the accumulation stage. The sedimentary material typically weathers from the continental landmass or offshore island arc; deep marine sediments can also be scraped from the subducting plate and piled onto the accretionary wedge. Thick sequences of sandstone, shale, and limestone with minor volcanic material accumulate along passive continental margins, such as the eastern coast of the United States. Sediments that accumulate along a convergent boundary (active continental margin) are more varied than those along a passive margin and often contain up to 50 percent andesitic flows and tuffs. Limestones are rare to absent. Graywackes are common and represent a rapid accumulation of sediment from a nearby magmatic arc. These sedimentary and volcanic deposits along the continental margins have been pushed up into many of the mountain ranges we see today.

Mountain-building convergence. Orogenesis is the mountain-building and associated folding, faulting, deformation, and metamorphism that result from the onset of intense tectonic stress. Igneous intrusions are also common. The layered rocks are tightly compressed into folds that often result in thrust faulting. The deepest rocks are metamorphosed into schists, gneisses, and migmatites. Compression also results in vertical uplift of the deformed rock sequence. Block faulting can also occur after the forces have thrust the metamorphosed and deformed rocks upward and outward.

Ocean-continent convergence deforms the accretionary wedge, metamorphoses rocks in the subduction zone, creates a mountainous magmatic arc, and develops fold-and-thrust belts on the backarc side of the magmatic arc. Ocean-continent convergence results in the formation of the rugged topography of the deep ocean trenches and seamounts. The magmatic arc is elevated because of the massive igneous upwellings underneath it.

Arc-continent convergence results when the intervening ocean is destroyed by subduction, welding an island arc to the continental edge. This convergence also results in deformation, uplift, and orogeny. Tectonic forces along the continental edge continue to generate heat, igneous intrusions, and compressional forces to the continental edge. It is probable that the northwestern United States was formed by a series of arcs that collided with and were welded to the North American craton.

Lhotse, world's 4th highest mountain The collision of two continental masses, or continent-continent convergence, also results in the formation of mountain belts. The thick sedimentary sequences that formed on both continental edges are squeezed into intensely deformed mountain ranges that are some of the highest in the world, such as the Himalayas between India and the rest of Asia. The Himalayas are still rising because of continued compression along the suture boundary, and they host frequent earthquakes. Some geologists theorize that the Appalachian Mountains in the eastern United States were built as a result of the collision of the European and African plates with the North American plate that helped form the supercontinent Pangaea. The Appalachians and the Caledonian Mountains of Great Britain and Norway were all once joined along the same suture zone before Pangaea rifted into the continents that we see today.

Postconvergence mountain-building. A mountain range undergoes additional uplift and block-faulting after orogeny has ceased. Because the continental crust was thickened during mountain-building, the gradual uplift over tens of millions of years is a result of isostatic adjustment. As material is eroded from the mountain belt, more uplift compensates for the loss of weight (mass) during erosion. The uplift creates vertical and extensional (tensional) stresses that result in the block-faulting of mountain ranges along a series of normal faults. Fault blocks may also be tilted if the stresses are unevenly distributed. Scattered volcanic activity can also be part of this phase of mountain development. Fault-blocked mountain ranges are usually separated by valleys filled with thousands of feet of sediment, such as those of the Great Basin (the Basin and Range region) in the western United States.

Much of our understanding of mountain-building processes has come from studying ancient mountain belts that have since eroded to form flat erosional surfaces. Fieldwork in mountain ranges can be difficult because the rocks are complexly folded and faulted and because of the great changes in elevation. But such fieldwork can be productive because these features are important in the mapping and examination of the third dimension of the earth.

Scientists can reconstruct mountain-building activity and plate moment in the past by studying terrestrial sediment deposits. Thick deposits generally mean bigger mountains as bigger slopes cause more material to erode than relatively flat plains.

Alpine Glaciers

Makalu, world's 5th highest mountain A typical Alpine glacier resembles a hand. The palm is the main part of the glacier and where snow is accumulating and turning into ice. The fingers, sometimes called tongues or snouts, are rivers of ice that flow down various valleys and out of the mountains.

Tributary glaciers are similar to the streams that feed a river. They are created in reaches of the mountains, where they scrape off rock and pick up gravel and carry them with into the main glacier, resulting in the twisting, parallel black lines that you often see in large glaciers.

Crevasses are large cracks that occur in glaciers. Icefalls are areas where the glacier is moving relatively quickly and breaking apart, producing large areas of crevasses and jagged ice. Calving refers to large pieces of ice falling off the end of glaciers. This is usually associated with glaciers that terminate in bodies of water, which causes the ice to melt and fracture more quickly. After a calved piece of ice falls into the water it becomes an iceberg.

Moraines are the walls of debris that mark the edge of major Alpine glacier tongues. When the ice melts at the bottom of a glaciers rock and soil are deposited. Over time large amounts of this debris accumulate into moraines.

Alpine Glacier Geological Features

Cho_Oyu, world's 6th highest mountain Glacier pick up and carry massive amounts of rock and soils. These and the ice itself can wear away the hardest rocks and scour the landscape under and beside a glacier, creating a geological features associated with glaciers.

Alpine glacier features include: 1) U-shaped valleys, mountain valleys that have been carved out by glaciers; 2) hanging valleys, U-shaped valleys that chopped off by a glacier going another direction, leaving a valley with a big cliff at its widest and lowest point (spectacular waterfalls often form here); 3) cirques, bowl-like basins formed by glacial erosion; 4) cols, jagged glacier-carved peaks.

Glaciers act like dams that store water in the winter and release it the summer when farmers most need it. But if too much water is releases, such as during a spring heavy rain, when spring melting is at peak, flood can occur. Sometimes lakes created within glaciers burst their dams and cause catastrophic flooding.

When a glacier retreats, the land is occupied by a succession of plants, beginning with lichens, grasses and flowering plants. As they produce detritus that fertilizes the soil, mat-forming trees such as willows appear. Within about 50 years, thickets of alder trees have established themselves. A mature forest generally takes about 200 to 250 years to establish itself after a glacier is gone.

Measuring Mountains

Dhaulagiri, world's 7th highest mountain Mountains do not have "official" heights because there is no officially designated international body that sorts out conflicting claims. The final word on such measurements in the United States is the United States Geological Survey. Outside the United States, for Americans anyway, it is often the National Geographic Society.

To calculate the elevation of mountains early surveyors used precision theodolites (high-resolution telescopes that measure horizontal and vertical angles) to take measurements from several different places. After the data was collected it was taken to surveying offices where men calculated the heights using complex formulas. The explorer Louis Baume wrote "the calculation of the heights of Himalayan peaks is a realm of such erudite complexity than even angels armed with theodolites and plum lines would dare to tread within." [Source: Jon Krakauer, Smithsonian]

Using the method of triangulation, a surveyor used a theodolite to "shoot the angle of the peak's rise" from two different locations, each of which had a known altitude. After measuring the distance between to the two locations, the survey team knew the side and two angles of triangle. Using a trigonometry the length of the other sides could be determined. After allowances were made for the curvature of the earth, atmospheric refraction, and plum line deflection caused by the gravity of a large object like a mountain a height figure could be determined.

Problems with Measuring Mountains the Traditional Way

Manaslu, world's 8th highest mountain Making allowances for the curvature of the earth is a relatively straight forward process but calculating atmospheric refraction, and plum line deflection is more of an art than a science

Atmospheric refraction is the bending of light by the atmosphere before it reaches the theodolite. It causes a mountain to appear higher than it really is and is influenced by things like temperature, humidity, atmospheric pressure which are constantly changing throughout out the day, causing measurements to rise or fall several hundred feet. The further away from a mountain measurements are made the greater the likelihood the surveyors measurements are off.

Another problem is how the altitude of the survey locations is determined. They too are made from the triangulation of two locations, and these locations are in turn made from the triangulation of two other locations, and so it goes on down the line until locations at sea level are reached. If errors are made at one location there errors are passed on to calculations of other locations.

Measuring Mountains the Modern Way

Today the elevation of mountains can be determined using Global Positioning System (GPS) devices, which measure the distance of the devise from the center of the earth using satellites. The distance from the center of the earth to sea level is determined accurately using the same method and subtracted from the original figure to give the height of the mountain.

Determining elevation with GPS is trickier than determining location, in terms of latitude and longitude. Readings have be taken from several locations to get an accurate overall reading.

The most difficult thing about using GPS devices, which weigh about four pounds, is getting them to the summits of mountains. As hard as that may be it is easier than lugging up much heavier surveying equipment and Doppler receivers, which ar also used to measure elevation.

Mountains and Global Warming

Global warming seems to be having a more profound impact on higher elevations than lower elevations the same ways it seems to a more profound affect on higher latitudes than lower latitudes. Temperatures are increasing at upper elevations. Vegetation that formality could not survive there has appeared. Taller plants are crowding out shorter tundra and high altitude plants

The higher elevations of Africa, the Andes mountains in South America, and the Alps in Europe are warming at a faster pace than lowlands. Forests are creping up to higher elevations along with disease-carrying insects.

The flamboyant multimillionaire Mou Qizhong suggested blasting a 30-mile hole in the Himalayas to let in warm air.

HIMALAYAS

Nanga_Parbat, world's 9th highest mountain The Himalayas as most everyone knows are the highest mountains in the world, with 30 peaks over 24,000 feet. The highest mountains in Europe, North and South America barely top 20,000 feet. The word Himalaya is Sanskrit for "abode of the snow" and a Himal is a massif of mountains. Technically Himalaya is the plural of Himal and there should be no such word as Himalayas.

The Himalayas stretch for 1,500 miles from eastern Tibet and China to a point where India, Pakistan, China and Afghanistan all come together. The mountain kingdoms of Sikkim, Bhutan and Nepal are all contained within the range. The southern side of the Himalayas are like a huge climatic wall. During the summer monsoon winds push massive rain clouds against the mountains squeezing out rain onto some of the wettest places on earth. On the leeward, rain-blocked side of the range, on the Tibetan plateau, are some of the driest and most barren places on the planet.

The Himalaya-Karakoram range contains nine of the world’s top ten highest peaks and 96 of the world's 109 peaks over 24,000 feet. If the Karakorum, Pamir, Tian Shan and Hindu Kush ranges and Tibet--which are extensions of the Himalayas into Pakistan, China, Afghanistan and Central Asia--are including in the Himalayas then the 66 highest mountains in the world are in the Himalayas. The 67th highest is Aconcagua in Argentina and Chile

Several of the greatest rivers in the world—the Ganges, Indus, Brahmaputra, Mekong, Yangtze and Yellow rivers—originate in either the Himalayas or the Tibetan plateau. Some people live in valleys nestled between Himalayan ridges but few people actually live on the slopes of the mountains.

Geology of the Himalayas

Annapurna, world's 10th highest mountain, with Fang The Himalayas are not just one range of mountains but a series of three parallel ranges that rise up from the plains of India, Pakistan and Bangladesh. Between the massifs and peaks are eroded river gorges, some of the deepest valleys in the world, and massive, slowly-creeping glaciers.

The southernmost range, the Siwalik Hills, barely tops 5000 feet. The Lesser Himalayas, in the middle, vary in altitude between 7,000 and 15,000 feet, and are indented with valleys like the Kathmandu Valley. The third range is known as the Great Himalayas and this is where all the world's biggest peaks are found.

The Himalayas are young mountains. Because of this they experience frequent landslides and rapid erosion, creating precipitous topography with sharp peaks and V-shaped ravines rather than alluvial valleys or lakes. Wind, rain, run off and snow continue shaping the mountains today. The mountains remain about the same height because the rate of erosion is about the same as the amount of uplift. The amount of snow also varies considerably. The greatest depths are recorded in the summer when the monsoons dump large amounts of snow on the higher elevation of the Himalayas. In the winter, high wind scour the landscape and blow snow away.

Himalayas and Plate Tectonics

Gasherbrum I, world's 11th highest mountain The Himalayas began 65 million years when the Indian subcontinent climaxed a 70 million year journey across the Indian Ocean with a collision into Asia. The force and pressure of the collision between the Asian plate and India, pushed massive folds of sedimentary rock up from out of the earth. The pressure and heat of the mountain building forces turned some of rock into metamorphic rocks such schists and gneisses. Wind, rain, run off and glacial ice created the awesome Alpine shapes you see today.

Much of the rock pushed upwards by the mountain building activity is limestone and sandstone that was once at the bottom of the ocean. It is possible to find fossils of sea creatures in the Himalayas at an elevation of four kilometers above sea level.

Plate tectonic continues to push the Indian subcontinent under Nepal and China, which sit on the Eurasian Plate, forcing Tibet and the entire Himalayan range to rise about 10 millimeters a year and move towards China at a rate if about five centimeters a year. Before it was pushed upwards Tibet was a well watered plain. As the Himalayas were pushed up they deprived Tibet of rain, turning it into a dry plateau.

The Indian Plate is moving northeastward at a rate of 1.7 inches a year relative to the Eurasian Plate which embraces most of Asia and Europe. A great amount of energy drives the collision and is released at the boundaries of the plates, which explains partly why India, Nepal , Tibet and China experience sometimes experience devastating earthquakes.

The Himalayas: Two Continents Collide

Broad Peak, world's 12th highest mountain Among the most dramatic and visible creations of plate-tectonic forces are the lofty Himalayas, which stretch 2,900 km along the border between India and Tibet. This immense mountain range began to form between 40 and 50 million years ago, when two large landmasses, India and Eurasia, driven by plate movement, collided. Because both these continental landmasses have about the same rock density, one plate could not be subducted under the other. The pressure of the impinging plates could only be relieved by thrusting skyward, contorting the collision zone, and forming the jagged Himalayan peaks. [Source: USGS]

About 225 million years ago, India was a large island still situated off the Australian coast, and a vast ocean (called Tethys Sea) separated India from the Asian continent. When Pangaea broke apart about 200 million years ago, India began to forge northward. By studying the history -- and ultimately the closing-- of the Tethys, scientists have reconstructed India's northward journey. About 80 million years ago, India was located roughly 6,400 km south of the Asian continent, moving northward at a rate of about 9 meters a century. When India rammed into Asia about 40 to 50 million years ago, its northward advance slowed by about half. The collision and associated decrease in the rate of plate movement are interpreted to mark the beginning of the rapid uplift of the Himalayas.

The 6,000-km-plus journey of the India landmass (Indian Plate) before its collision with Asia (Eurasian Plate) about 40 to 50 million years ago (see text). India was once situated well south of the Equator, near the continent of Australia. The Himalayas and the Tibetan Plateau to the north have risen very rapidly. In just 50 million years, peaks such as Mt. Everest have risen to heights of more than 9 km. The impinging of the two landmasses has yet to end. The Himalayas continue to rise more than 1 cm a year -- a growth rate of 10 km in a million years! If that is so, why aren't the Himalayas even higher? Scientists believe that the Eurasian Plate may now be stretching out rather than thrusting up, and such stretching would result in some subsidence due to gravity.

Gasherbrum 2, world's
13th highest mountain Fifty kilometers north of Lhasa (the capital of Tibet), scientists found layers of pink sandstone containing grains of magnetic minerals (magnetite) that have recorded the pattern of the Earth's flip-flopping magnetic field. These sandstones also contain plant and animal fossils that were deposited when the Tethys Sea periodically flooded the region. The study of these fossils has revealed not only their geologic age but also the type of environment and climate in which they formed. For example, such studies indicate that the fossils lived under a relatively mild, wet environment about 105 million years ago, when Tibet was closer to the equator. Today, Tibet's climate is much more arid, reflecting the region's uplift and northward shift of nearly 2,000 km. Fossils found in the sandstone layers offer dramatic evidence of the climate change in the Tibetan region due to plate movement over the past 100 million years.

At present, the movement of India continues to put enormous pressure on the Asian continent, and Tibet in turn presses on the landmass to the north that is hemming it in. The net effect of plate-tectonics forces acting on this geologically complicated region is to squeeze parts of Asia eastward toward the Pacific Ocean. One serious consequence of these processes is a deadly "domino" effect: tremendous stresses build up within the Earth's crust, which are relieved periodically by earthquakes along the numerous faults that scar the landscape. Some of the world's most destructive earthquakes in history are related to continuing tectonic processes that began some 50 million years ago when the Indian and Eurasian continents first met.

MT. EVEREST

Everest from Rombok Gompa,Tibet Mt. Everest is 29,028 feet high (5½ miles high). Taller than 21 Empire State buildings piled on top of one another and almost as high as the cruising altitude of Boeing 747 jumbo jets, Mt. Everest is so high that it sometimes penetrates the jet stream, blowing mountain climbers off the top, and dozens of feet have to be subtracted from surveying measurements to compensate for the gravity created by the mountain.

Located on the border of Tibet (China) and Nepal, Mt. Everest is sometimes referred to as the third pole. It was first known to British surveyors—who first sighted it many miles away in Denhra Dun in India and took measurements of its heights from there—as Peak XV. In 1852 it became significant when a Bengali clerk working in an office in Delhi exclaimed "I have discovered the highest mountain in world" after tabulating measurements of Peak XV from different survey stations across northern India in 1849 and 1850.

Mt. Everest is named after the British after Sir George Everest, a Welshman and the Surveyor General of the Great Trigonometric Survey of India and the man in charge of mapping India between 1830 and 1843. Everest most likely never saw the mountain named after him. It is believed he would likely have preferred a local name given to tthe mountain.

The Nepalese call Mt. Everest "Samgarmatha" ("Goddess of the Universe" or literally “Forehead of the Sky”) and Sherpas and Tibetans call it "Qomolangma" or Chomolungma ("Goddess Mother of the Land"). For them the mountain is sacred and the idea of climbing it, until recently, was strange. According to a Sherpa legend Mt. Everest is the home of a goddess bearing a bowl of food and a mongoose spitting jewels. Mt. Everest is located at about the same latitude as Tampa, Florida.

Climbers say that other mountains are much more difficult to climb than Mt. Everest. Jan Morris, who accompanied the first successful Everest expedition, wrote: “It’s not the most beautiful of mountains—several of its neighbors were shapelier—but whether in fact or simply in the mind, it seems conspicuously nobler than any of them.” Among the most impressive sights at the summit is the pyramid-shapes shadow that Everest produces at sunrise and sunset. Hardly anybody has been it from the summit itself because few climbers are there at those times.

Measuring the Height of Mt. Everest

Climbing routes on Tibetan side
Using a global positional device (GPS) placed on the summit in 1999, scientists at the University of Colorado calculated the height of Mt. Everest to be 29,035 feet, or 8,500 meters.(with a margin of error or plus or minus seven feet). This is seven feet higher than earlier estimates. The new height was recognized by the National Geographic Society and placed on their maps.

The measurements were made after a Seattle-based astronomer claimed in 1987 that K2 in Pakistan might be 29,064 feet high, making it higher that Mt. Everest. The K2 measurement was made measuring the altitude of a knoll near K2 using a 75-pound Doppler receiver (a device that measures distance through analysis of slight variations in the wavelength of radio waves) on the knoll and a satellite passing overhead and then using ordinary triangulation to determine the height of K2.

The first survey of Mt. Everest in the 1850s came up with the altitude figure of 29,002 feet based on measurements taken at six sites in the India plains. A second survey made at the turn of the century determined the height of Mt. Everest was 29,141 feet. In the 1954, when Indian surveyors made 12 readings at locations much closer to the mountain, they came with the widely accepted elevation of 29,028 feet (8,848 meters).

The global positioning device taken to the summit of Mt. Everest in 1998 was placed there by mountain climbers. The devise also determined that Everest is still rising at a rate of about a third of an inch every year and moving northeast at rate of three inches a year. Recently a Chinese mountaineering revised the height of Mt. Everest as four meters lower.

Still there is some debate as to what is the world's highest mountain. Mauna Kea on the island of Hawaii stands 33,480 feet above the ocean floor and 13,796 feet above sea level. According to the Guinness Book of Records, Chimborazo, a 20,560-feet-high volcano in Ecuador, is 7,054 feet further from the center of the earth than Mt. Everest. It's distance from the earth's center is a result of the fact that Chimborazo is only 98 miles from the equator (the earth is slightly flat at the poles and wide at the equator). Chimborazo was thought to bebthe highest mountain in the world until the 1850s.

Surveying Mt. Everest

Because the original measurements of Mt. Everest were made from the faraway plains of India, the height calculations were corrected by as much as 1,375 feet to compensate for refraction alone. Moreover, the chain of triangulation locations began 1,000 miles way in Madras. For K2, they began 1,700 miles away in Madras.

The early surveyors were prohibited from crossing into Tibet by the Chinese emperor. To get around this the British hired local tribesmen who disguised their surveyor chains as prayer beads. These tribesmen were educated men known as "pandits." The word "pundit," an expression which originally meant "learned man" was derived from the name of this group.

All measurements of Mt. Everest are based on the elevation of the snowcap on the summit not the summit itself. No one knows how deep the snow is and it may vary as much as three feet in the course of a year.

Image Sources: Wikimedia Commons; Except Everest climbing routes, Luca Galuzzi and Alan Arnette

Text Sources: New York Times, Washington Post, Los Angeles Times, Times of London, National Geographic, The New Yorker, Time, Newsweek, Reuters, AP, Lonely Planet Guides, Compton’s Encyclopedia and various books and other publications.

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© 2008 Jeffrey Hays

Last updated April 2010