Makalu

Long ago, the land of India moved north. It pushed into Asia.

The rock crumpled and rose up. That made the Himalayas, with Makalu.

The US Geological Survey (USGS) explains that India was once a large island far to the south. It drifted north and rammed into Asia about 40 to 50 million years ago. Neither piece of land could sink under the other, so the rock was pushed up into the jagged Himalayan peaks.

Deep inside the mountains, rock got so hot that some of it melted. Near Makalu, that melted rock cooled into a pale granite called the Makalu leucogranite.

The USGS describes India's collision with Asia about 40 to 50 million years ago: because both landmasses have about the same rock density, neither was subducted, and the pressure was relieved by thrusting skyward. It says the Himalayas still rise more than 1 cm a year.

A 2010 study by Streule and colleagues describes the Makalu leucogranite in the eastern Nepal Himalaya as a multiphase intrusion of sheets along the top of the Greater Himalayan Sequence, part of a chain of Miocene granites along the range. Its main melting phase was 24 to 21 million years ago, with the latest melting about 16 million years ago; the authors say the data support a 'channel flow' model, in which a partly molten middle crust was squeezed southward.

Rivers of ice called glaciers flow down beside Makalu.

At the end of one glacier there is a lake.

JAXA's satellite view shows the Barun Glacier flowing on the west side of Makalu and the Lower Barun Glacier on its southwest side. Lakes lie at the ends of these glaciers, and the Kangshung Glacier is on the mountain's north side.

The International Centre for Integrated Mountain Development (ICIMOD) calls the Lower Barun glacial lake one of Nepal's critical glacial lakes. It has been growing quickly as chunks of the glacier break off into it.

In JAXA's January 2007 satellite image, the Barun Glacier flows on Makalu's west side and the Lower Barun Glacier on its southwest side, with Barun Pokhari and the Lower Barun Glacial Lake at their ends; the Kangshung Glacier lies on the north side, and Pyramid Peak (6,809 m) is 11 km to the southwest.

ICIMOD describes the Lower Barun glacial lake, in the foothills of Makalu, as one of Nepal's critical glacial lakes: it is dammed by an ice-cored moraine on one side and a calving, debris-covered glacier on the other, and it has been expanding rapidly through calving. For September 2021, ICIMOD and Kathmandu University planned fieldwork to survey its depth and its moraine. In 2018, an expedition supporting ESA's Climate Change Initiative surveyed the Barun Glacier to help understand the region's past climate.

Below the ice, the valleys have forests.

Scientists found more than one hundred kinds of orchids there.

In Makalu-Barun National Park in Nepal, one study looked at land from tropical valleys at 350 meters up to subalpine slopes at 3,500 meters. A botany student at Tribhuvan University, Dambar Bahadur Karkee, made two field visits in 1998 and 1999 and recorded 107 kinds of orchids in the park.

Most of them were epiphytes: plants that grow on the trunks and bark of trees rather than in the soil.

A dissertation at Tribhuvan University's Central Department of Botany (Karkee, 2008), based on field visits in 1998 and 1999, recorded 107 orchid species in 47 genera in Makalu-Barun National Park: 74 epiphytes, 31 terrestrial, 2 lithophytes and 1 saprophyte, with Dendrobium the largest genus (9 species).

Its study zones ran from a tropical region at 350-1,000 m to a subalpine region at 3,000-3,500 m, which held 7 terrestrial species. The study reported Oberonia parvula subsp. arunense as a new taxon and Tainia minor as a new record for Nepal.

Makalu is very hard to climb. Its ridges are thin and sharp.

High up, the air has less oxygen. People can get headaches and feel sick.

ESA says Makalu's knife-edge ridges and remote, exposed position lead many people to see it as one of the world's most difficult mountains to climb. In 1955, a climbing team that included Jean Franco reached the top.

Visitors to high places can get altitude sickness. The US Centers for Disease Control and Prevention (CDC) says children are as likely to get it as adults, and headache is its main sign. Going down at least 300 meters helps.

ESA's 2018 description notes that Makalu's knife-edge ridges and remote, exposed position make it, in many people's view, one of the world's most difficult mountains to climb. A 1958 review in the American Alpine Journal of Jean Franco's book 'Makalu' recalls the 1955 ascent that Franco, one of the climbers, describes, in which the entire climbing team, including a few Sherpas, reached the summit during a 72-hour period.

The CDC's Yellow Book says any unacclimatized traveler sleeping at 2,450 m or higher is at risk of altitude illness, that children are as susceptible as adults, and that headache is the cardinal symptom of acute mountain sickness, which improves rapidly with a descent of 300 m or more.