MOUNTAINS IN TIBET
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.
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) volcanos.
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.
The higher you climb the colder it gets. This is because as air rises it expands and therefore cools. On average the temperature drops 1°F for every 300 feet rise in elevation. Above the freezing line snow falls and may accumulate into glaciers.
Good Websites and Sources on Tibetan Environmental Issues: Tibet Environmental Watch tew.org ; tibet.org ; CNN report on China Exploiting Tibetan Resources money.cnn.com ; China Daily report on Huge Mineral Resources in Tibet chinadaily.com ; Free Tibet on Mineral Extraction freetibet.org ; Global Warming and Tibetan Glaciers The Independent ; China Daily on Global Warming in Tibet chinadaily.com
Mountains: China Trekking China Trekking ; 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
Links in this Website: TIBETAN NATURE Factsanddetails.com/China ; Factsanddetails.com/China ; MOUNTAINS IN TIBET Factsanddetails.com/China ; GLACIERS AND AVALANCHES IN TIBET Factsanddetails.com/China ; TIBETAN ANIMALS AND PLANTS Factsanddetails.com/China ; SNOW LEOPARDS Factsanddetails.com/China ; SHAHTOOSH AND CHIRUS Factsanddetails.com/China ; YAKS Factsanddetails.com/China
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
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.
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
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
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.
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
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: Kalachakranet.org, Purdue University
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.
© 2008 Jeffrey Hays
Last updated April 2010