The Making of the Himalaya, Karakoram, and Tibetan Plateau

My quest to figure out how the great mountain ranges of Asia, the Himalaya, Karakoram, and Tibetan Plateau were formed has thus far lasted over thirty years from my first glimpse of those wonderful snowy mountains of the Kulu Himalaya in India, peering out of that swaying Indian bus on the road to Manali. It has taken me on a journey from the Hindu Kush and Pamir Ranges along the North-West Frontier of Pakistan with Afghanistan through the Karakoram and along the Himalaya across India, Nepal, Sikkim, and Bhutan and, of course, the great high plateau of Tibet. During the latter decade I have extended these studies eastwards throughout South East Asia and followed the Indian plate boundary all the way east to the Andaman Islands, Sumatra, and Java in Indonesia. There were, of course, numerous geologists who had ventured into the great ranges over the previous hundred years or more and whose findings are scattered throughout the archives of the Survey of India. These were largely descriptive and provided invaluable ground-truth for the surge in models that were proposed to explain the Himalaya and Tibet. When I first started working in the Himalaya there were very few field constraints and only a handful of pioneering geologists had actually made any geological maps. The notable few included Rashid Khan Tahirkheli in Kohistan, D. N. Wadia in parts of the Indian Himalaya, Ardito Desio in the Karakoram, Augusto Gansser in India and Bhutan, Pierre Bordet in Makalu, Michel Colchen, Patrick LeFort, and Arnaud Pêcher in central Nepal. Maps are the starting point for any geological interpretation and mapping should always remain the most important building block for geology. I was extremely lucky that about the time I started working in the Himalaya enormous advances in almost all aspects of geology were happening at a rapid pace. It was the perfect time to start a large project trying to work out all the various geological processes that were in play in forming the great mountain ranges of Asia. Satellite technology suddenly opened up a whole new picture of the Earth from the early Landsat images to the new Google Earth images.

Roof of the World: Tibet, Pamirs

The Tibetan Plateau is by far the largest region of high elevation, averaging just above 5,000 metres above sea level, and the thickest crust, between 70 and 90 kilometres thick, anywhere in the world. This huge plateau region is very flat—lying in the internally drained parts of the Chang Tang in north and central Tibet, but in parts of the externally drained eastern Tibet, three or four mountain ranges larger and higher than the Alps rise above the frozen plateau. Some of the world’s largest and longest mountain ranges border the plateau, the ‘flaming mountains’ of the Tien Shan along the north-west, the Kun Lun along the north, the Longmen Shan in the east, and of course the mighty Himalaya forming the southern border of the plateau. The great trans-Himalayan mountain ranges of the Pamir and Karakoram are geologically part of the Asian plate and western Tibet but, as we have noted before, unlike Tibet, these ranges have incredibly high relief with 7- and 8-kilometre-high mountains and deeply eroded rivers and glacial valleys. The western part of the Tibetan Plateau is the highest, driest, and wildest area of Tibet. Here there is almost no rainfall and rivers that carry run-off from the bordering mountain ranges simply evaporate into saltpans or disappear underground. Rivers draining the Kun Lun flow north into the Takla Makan Desert, forming seasonal marshlands in the wet season and a dusty desert when the rivers run dry. The discovery of fossil tropical leaves, palm tree trunks, and even bones from miniature Miocene horses suggest that the climate may have been wetter in the past, but this is also dependent on the rise of the plateau. Exactly when Tibet rose to its present elevation is a matter of great debate. Nowadays the Indian Ocean monsoon winds sweep moisture-laden air over the Indian sub-continent during the summer months (late June–September). All the moisture is dumped as the summer monsoon, the torrential rains that sweep across India from south-east to north-west.

The Day the Earth Shook: The Sumatra–Andaman Earthquake 2004

At 00.58 GMT (7.58 local time) on Sunday, 26 December 2004 a massive earthquake occurred off the north-west coast of Sumatra. The earthquake measured between magnitude 9.0 and 9.3 on the Richter scale with its epicentre at 3.32oN, 95.85oE, and occurred at a depth of approximately 30 kilometres. It was the second largest earthquake recorded since instrumental records began and was the deadliest natural disaster in recorded history. The earthquake and the resulting tsunami are estimated to have killed at least 228,000 people across fifteen countries bordering the Indian Ocean. The worst affected countries were Indonesia, Sri Lanka, India, Thailand, Burma, the Maldives, and Somalia. The earthquake occurred on the subduction zone interface between the down-going Indian Ocean plate and the overriding Burma–Andaman–Sumatra plate. It ruptured approximately 1600 kilometres’ length of the plate boundary from Sumatra all the way north to the Burmese coast, travelling at 2–3 kilometres per second. Aftershocks continued unrelentingly for over four months after the earthquake, several reaching magnitude 7.5 as far north as the northern Andaman Islands. The seismic waves indicated a thrust fault earthquake that tilted the surface up to the south-west and down to the north-east. The ground surface was elevated as much as 11 metres at the epicentre, with the tilted surface sinking up to one metre further to the north-east, offshore Sumatra. During the rupture, the Burma plate slipped as much as 15 metres horizontally as the Indian Ocean plate slipped beneath. The force of the quake perceptibly shifted the Earth’s axis, raised sea level globally and speeded Earth’s rotation. It has been suggested that the earthquake shortened the length of the day by 2.68 microseconds, because of the decrease in oblateness of the Earth. The earthquake caused the Earth to wobble on its axis by up to 2.5 cm in the direction of 145o east longitude. The natural ‘Chandler wobble’, a small motion in the Earth’s axis of rotation (the motion that occurs when the spinning object is not a perfect sphere) can be up to 9 metres over 433 days, so this eventually offsets the comparatively minor wobble produced by the earthquake.

Mountains and Maoists: Annapurna, Manaslu

Sarangkhot village is perched on top of a hill overlooking the Phewa Lake and Nepal’s second city of Pokhara. The views from here are some of the most wonderful in all the Himalaya. To the north-west, the huge snowy ramparts of Dhaulagiri rise above the Kali Gandaki Gorge, one of the world’s deepest canyons. East of the Kali Gandaki the whole Annapurna Range forms an icy rampart that blocks the entire northern horizon, with the majestic spire of Machapuchare, the ‘Fish Tail’, rearing up in the foreground. Hanging glaciers clinging to the side of Machapuchare glisten in the sunlight and cascade down to the green bamboo jungles of the Seti khola. The Annapurnas extend east into the Lamjung Himal, and then across another deep canyon, the Burhi Gandaki, the 8,000-metre-high massif Manaslu appears on the far eastern horizon. Winds funnel down the Pokhara Valley and rise up to the ridge at Saranghot, making this the perfect take-off place for hang-gliders. To jump off the ridge at Saranghot and see the whole Nepalese Himalaya unfurl to the north, ride the thermals with the black kites, eagles, and vultures cruising alongside, and land back at the lakeside is one of the new wave of extreme sports to have recently caught on in Nepal. It is difficult not to like Pokhara. The monsoonal rains in Nepal can be dramatic. Clouds gradually form in the late morning, welling up the valley to hug the high peaks, with just the tips of the mountains standing clear and proud above a sea of cloud. Suddenly the skies darken, streaks of lightning appear out of nowhere, and thunderclaps ricochet around the mountain walls. One or two large raindrops herald a torrential monsoonal downpour, rain falling out of black clouds in sheets. Trickles of water in rivulets become raging torrents in minutes, and very soon waterfalls gush over every cliff. The rains finally ease as suddenly as they started, the skies gradually clearing as mists linger in the deep forested valleys.

North-West Frontier: Kohistan, Hindu Kush, Pamirs

The Hindu Kush Mountains run along the Afghan border with the North-West Frontier Province of Pakistan. Following the First Anglo-Afghan war of 1839– 42 the British government in Simla decided that the North-West Frontier of British India had to have an accurate delineation. Sir Mortimer Durand mapped the border between what is now Pakistan and Afghanistan in 1893 and this frontier is known as the Durand Line. Unfortunately it is a political frontier and one that splits the Pathan or Pushtun-speaking lands into two, with the North-West Frontier Province and Waziristan in Pakistan to the east and the Afghan provinces of Kunar, Nangahar, Khost, Paktiya, and Kandahar to the west. The border regions north of Baluchistan in Quetta and Waziristan are strong tribal areas and ones that have never come under the direct rule of the Pakistani government. Warlords run their drug and arms businesses from well-fortified mud-walled hilltop fortresses. During the period that Lord Curzon was Viceroy of India from 1899 to 1905 the entire border regions of British India were mapped out along the Karakoram, Kashmir, Ladakh, and south Tibetan Ranges. During Partition, in 1947, once again an artificial border was established separating mostly Muslim Pakistan from India. Lord Mountbatten, the last Viceroy, gave Sir Cyril Radcliffe the invidious task of delineating the border in haste to avoid a civil war that would surely have come, and on 17 August 1947 Pakistan inherited all the territory between the Durand Line and the new Indian frontier, the Radcliffe Line. In the north, the disputed Kashmir region still remained unresolved and the northern boundary of Pakistan ran north to the main watershed along the Hindu Kush, Hindu Raj, and Karakoram Ranges. To the west, Afghanistan was a completely artificial country created by the amalgamation of the Pathans of the east, Hazaras of the central region, the Uzbeks in the Mazar-i-Sharif area, and the Tadjiks of the Panjshir Valley along the border with Pakistan’s North-West Frontier Province. The British lost three wars trying to invade this mountainous land between 1839 and 1919, and the Soviet Union which occupied Afghanistan for ten years from 1979 also withdrew across the Oxus River in failure in February 1989.

Frozen Rivers and Fault Lines

After seven summer field seasons working in the north-western Himalaya in India, I had heard of a winter trade route that must rank as one of the most outlandish journeys in the Himalaya. The largely Buddhist Kingdoms of Ladakh and Zanskar are high, arid, mountainous lands to the north of the Greater Himalayan Range and in the rain shadow of the summer monsoon. Whereas the southern slopes of the Himalaya range from dense sub-tropical jungles and bamboo forests to rhododendron woods and magnificent alpine pastures carpeted in spring flowers, the barren icy lands to the north are the realm of the snow leopard, the yak, and the golden eagles and lammergeier vultures that soar overhead. The Zanskar Valley lies immediately north-east of the 6–7,000-metre-high peaks of the Himalayan crest and has about thirty permanent settlements, including about ten Buddhist monasteries. I had seen the Zanskar Ranges from the summit of White Sail in Kulu and later spent four summer seasons mapping the geology along the main trekking routes. In summer, trekking routes cross the Himalaya westwards to Kashmir, southwards to Himachal Pradesh, and northwards to Leh, the ancient capital of Ladakh. Winter snows close the Zanskar Valley from the outside world for up to six months a year when temperatures plummet to minus 38oC. Central Zanskar is a large blank on the map, virtually inaccessible, with steepsided jagged limestone mountains and deep canyons. The Zanskar River carves a fantastic gorge through this mountain range and for only a few weeks in the middle of winter the river freezes. The Chaddur, the walk along the frozen Zanskar River, takes about ten to twelve days from Zanskar to the Indus Valley and, in winter time, was the only way in or out before the road to Kargil was constructed. I mentioned this winter trek to Ben Stephenson during our summer fieldwork in Kishtwar and he stopped suddenly, turned around, and said ‘Mike we just have to do this trek!’ So the idea of a winter journey into Zanskar was born, and four of us set off from Oxford in January 1995.

Around the Bend: Nanga Parbat, Namche Barwa

From the geological mapping, structural, and metamorphic investigations along the main Himalayan Range from Zanskar in the west through the Himachal Pradesh and Kumaon regions of India and along the whole of Nepal to Sikkim, a similar story was emerging. The overall structure and distribution of metamorphic rocks and granites was remarkably similar from one geological profile to the next. The Lesser Himalaya, above the Main Boundary Thrust was composed of generally older sedimentary and igneous rocks, unaffected by the young Tertiary metamorphism. Travelling north towards the high peaks, the inverted metamorphism along the Main Central Thrust marked the lower boundary of the Tertiary metamorphic rocks formed as a result of the India–Asia collision. The large Himalayan granites, many forming the highest peaks, lay towards the upper boundary of the ‘Greater Himalayan sequence’. North of this, the sedimentary rocks of the Tethyan Himalaya crop out above the low-angle normal fault, the South Tibetan Detachment. The northern ranges of the Himalaya comprise the sedimentary rocks of the northern margin of India. The two corner regions of the Himalaya, however, appeared to be somewhat different. The Indian plate has two major syntaxes, where the structural grain of the mountains swings around through ninety degrees: the western syntaxis, centred on the mountain of Nanga Parbat in Pakistan, and the eastern syntaxis, centred on the mountain of Namche Barwa in south-east Tibet. Nanga Parbat (8,125 m) is a huge mountain massif at the north-western end of the great Himalayan chain. It is most prominent seen from the Indus Valley and the hills of Kohistan to the west, where it seems to stand in glorious isolation, ringed by the deep gorges carved by the Indus and Astor Rivers, before the great wall of snowy peaks forming the Karakoram to the north.

Mapping the Geology of Everest and Makalu

There are few places in the world where a geologist can actually take a look at the rocks and structures 5 or 6 kilometres down beneath the Earth’s surface. The opposing forces of nature—the uplift of rocks towards the Earth’s surface and their erosion and removal—usually balance each other out, at least roughly. It is only where the rate of uplift of rocks greatly exceeds erosion that high mountains are built. This is precisely why the Himalaya are so unique to geologists studying mountain-building processes. The Himalaya is an active mountain range: the plate convergence rates are high, uplift rates are extremely high, and glacial and fluvial erosion has carved deep channels in between the mountains. By walking and climbing all around Everest we can actually map and study the rocks in three dimensions, which elsewhere, beneath the Tibetan Plateau for example, remain buried below the Earth’s surface. After the Survey of India discovered that Mount Everest was the highest mountain in the world, a pioneering expedition set out to fly across the summit and take photographs. On 3 April 1933 a Houston-Weston biplane piloted by Lord Clydesdale flew across the summit and took the first photos of the mountain. Clydesdale wrote: ‘We were in a serious position. The great bulk of Everest was towering above us to the left, Makalu down-wind to the right and the connecting range dead ahead, with a hurricane wind doing its best to carry us over and dash us on the knife-edge side of Makalu.’ The earliest geologists to study the structure of Mount Everest, A. M. Heron and Noel Odell, both noted the apparent conformity of strata with sedimentary rocks on top of the mountain lying above the more metamorphosed rocks around the base In his 1965 paper on the structure of Everest, Lawrence Wager wrote: ‘It never ceases to surprise the writer that the highest point of the Earth’s surface is composed of sedimentary rocks which are relatively flat-lying and but little metamorphosed.’

Oceans and Continents

Sitting atop a rickety Indian bus trundling up the Beas Valley to the delightful hill station of Manali in the Kulu Valley of Himachal Pradesh, peering between swaying bodies and piles of luggage, I caught my first glimpse of the snowy peaks of the Himalaya. Yes, those white streaks way up in the sky were not, after all, clouds: they were glints of sunlight on impossibly high and steep ice-fields plastered onto the sides of mountains that tore up into the sky. It was a sight to take one’s breath away and I knew instantly that this was going to be the start of a great adventure. We were a typical shoestring British student expedition of five friends who could fit easily into two overloaded rickshaws, heading for the mountains around the Tos Glacier. Mountaineers dream about climbing in the Himalaya. Since my earliest days of climbing the hills and crags of Snowdonia and northern Scotland, I had yearned to see and climb those magical Himalayan Mountains. Now here I was, and the reality of the Himalaya was even better than I imagined. I had taken three months off from my PhD studies on the geology of the Oman Mountains to go on this expedition. We had driven a Land Rover out from England to Muscat through a snowy Europe and across the Empty Quarter of Arabia from Syria and Jordan to the United Arab Emirates and Oman. After three months’ fieldwork in Oman I caught a passenger ship, the MV Dwarka, last of the British East India Company merchant vessels that plied the Gulf route from Basra via Kuwait, Bahrain, Dubai, and Muscat to Karachi, and then travelled through Pakistan by train into India. That first expedition to Kulu was a revelation. We camped on the Tos Glacier, four days’ walk above the village of Manikarin in the Parbati Valley of eastern Kulu, for about four weeks. During that time the weather was perfect almost every day.

Faces of Everest

Trekking to Everest from the Sola Khumbu in Nepal is most definitely one of life’s great treats. When Nepal first opened up to foreigners in 1950 there was only one road from India to Kathmandu via the border town of Raxaul. Early expeditions to Everest had to trek from the plains of India either from Jogbani or Jaynagar in south-eastern Nepal. For the purist, the trail nowadays starts in the Kathmandu Valley, whilst the road head at the village of Jiri is the normal starting point for overlanders. The first week’s walking goes from west to east towards the village of Junbesi, against the grain of the land, crossing three passes and several rivers draining south from the Rolwaling and Khumbu Himalaya. Once across the Dudh Kosi River and up the hill to Lukla, the trail heads north up into the high country. Many trekkers nowadays fly directly into Lukla, where the plane lands at the impressive and frighteningly tilted airstrip built by Edmund Hillary and his Sherpa friends high on the side of the Dudh Kosi. From Lukla, the trail winds through forests of blue pine, fir, silver birch, and the ubiquitous rhododendron. In spring the hills are a mass of red, pink, and white rhododendrons. Meadows are carpeted in wild flowers—gentians, primrose, edelweiss, and the magical Himalayan blue poppy. Small Sherpa villages with their sturdy homes built from slabs of schist and gneiss have expanded with new trekking lodges springing up annually. The terraced rice paddies of the lowlands are soon left behind and apple orchards are a mass of blooms in the spring. Clouds well up and float quietly down into the valleys. The forests with their hanging mosses become eerily quiet. The senses dwell on the serene beauty of the forests and streams, all green and full of life and sound. Suddenly one’s eye is caught by something higher up, way above the clouds. With amazement, one realizes that is no cloud up there: it is a mountain, five miles high, far above the peaceful green of the valley.