Karakoram

The Karakoram mountain range spans the borders of Pakistan, China, and India, with its northwestern edges stretching into Afghanistan and Tajikistan. It is the second-highest mountain range on Earth and holds four of the world’s fourteen eight-thousanders, the tallest being K2, the second highest mountain on the planet. The range is roughly 500 kilometers long and is the most glaciated place outside the polar regions, with the Siachen Glacier (76 kilometers) and Biafo Glacier (63 kilometers) ranking as the second- and third-longest non-polar glaciers. It contains eighteen summits above 7,500 meters in elevation, including four above 8,000 meters: K2, Gasherbrum I, Broad Peak, and Gasherbrum II.

The Karakoram begins in the Wakhan Corridor of eastern Afghanistan and extends east into Indian-administered Ladakh, Chinese-administered Aksai Chin, and China’s Xinjiang province. Most of the range lies within Pakistan-administered Gilgit-Baltistan. Its eastern boundary is the Aksai Chin plateau; to the northeast lies the edge of the Tibetan Plateau; and to the north are the Yarkand and Karakash river valleys, beyond which are the Kunlun Mountains. The Pamir Mountains sit at the northwestern corner, while the Hindu Kush lies to the west. The southern boundary is formed, from west to east, by the Gilgit, Indus, and Shyok rivers, which separate the Karakoram from the northwestern end of the Himalayas. These rivers flow northwest before turning sharply southwest toward Pakistan’s plains. Roughly in the middle of the range is the Karakoram Pass, once part of a now-unused trade route between Ladakh and Yarkand.

The name “Karakoram” is Turkic for “black gravel.” Central Asian traders first applied it to the Karakoram Pass. Early European travelers like William Moorcroft and George Hayward later used the term for the mountains west of the pass, though they also called them Muztagh (“Ice Mountain”). In the 1850s, Thomas Montgomerie of the Survey of India labeled the high peaks K1 through K6 (“K” for Karakoram) from his station at Mount Haramukh. In Sanskrit literature (the Puranas), the range was called Krishnagiri (black mountains), with vernacular variations Kanhagiri and Kanheri.

Due to its altitude and ruggedness, the Karakoram is far less inhabited than parts of the Himalayas further east. European explorers first arrived in the early 19th century, followed by British surveyors from 1856. Colonel Francis Younghusband’s expedition crossed the Muztagh Pass in 1887, and General Sir George K. Cockerill explored the valleys above the Hunza River in 1892. Explorations in the 1910s and 1920s established most of the region’s geography. The name “Karakoram” was used in the early 20th century by Kenneth Mason for what is now called the Baltoro Muztagh, but today it refers to the entire range from the Batura Muztagh above Hunza in the west to the Saser Muztagh in the bend of the Shyok River in the east. Floral surveys were conducted in the Shyok River catchment and from Panamik to Turtuk village by Chandra Prakash Kala during 1999 and 2000.

The Karakoram lies in one of the world’s most geologically active areas, at the plate boundary between the Indo-Australian and Eurasian plates. Between 28 and 50 percent of the range is glaciated, covering an area of more than 16,000 square kilometers, compared to 8–12 percent of the Himalayas and 2.2 percent of the Alps. Mountain glaciers can indicate climate change, advancing and retreating with long-term shifts in temperature and precipitation. Karakoram glaciers are slightly retreating, but unlike the Himalayas, where glaciers lose mass at a significantly higher rate, many are covered in a layer of rubble that insulates the ice from the sun. Where no such insulation exists, retreat is rapid. Some recent studies show a slight increase or stability in glacier mass in central and western Karakoram, termed the “Karakoram Anomaly,” contrasting with eastern Karakoram glaciers, which are retreating. Notable glaciers include Siachen, Baltoro, Hispar, Batura, Biafo, Chogo Lungma, and Yinsugaiti.

During the last ice age, a connected series of glaciers stretched from western Tibet to Nanga Parbat and from the Tarim Basin to the Gilgit District. To the south, the Indus glacier was the main valley glacier, flowing down from the Nanga Parbat massif to 2,000 meters elevation. In the north, Karakoram glaciers joined those from the Kunlun Mountains and flowed down to 2,000 meters in the Tarim Basin. While current valley glaciers reach a maximum length of 76 kilometers, several ice-age valley glacier branches and main glaciers had lengths up to 700 kilometers. The glacier snowline was about 1,500 meters lower than today.

The majority of the highest peaks are in Pakistan-administered Gilgit-Baltistan. Baltistan has more than 100 mountain peaks exceeding 6,000 meters in height. The highest peaks include K2, Gasherbrum I, Broad Peak, and Gasherbrum II, along with others named with K codes.