| Pastoruri Glacier | |
|---|---|
 View of Pastoruri Glacier in 2010 | |
| Type | Valley glacier |
| Location | Peru |
| Coordinates | 09°55′12″S77°10′56″W / 9.92000°S 77.18222°W |
| Area | 8 km2 (3.1 sq mi) |
| Length | 4 km (2.5 mi) |
| Terminus | Lake |
| Status | Retreating |
The Pastoruri glacier is a cirque glacier, located in the southern part of the Cordillera Blanca, part of the Andes mountain range, in Northern Peru in the Ancash region. It is one of the few glaciers left in the tropical areas of South America. [1]
The glacier is around 8 square kilometres (3.1 sq mi) in size, and around 4 kilometres (2.5 mi) long with a terrestrial snout ending. [1] The glacier is currently retreating quickly. It has lost 22% of its size and 15.5% of its ice mass in the last 30–35 years. [2]
The glacier occupies an Andean peak around 5,250 metres (17,200 feet) above sea level, and so has steep, cliff like edges, with heavily crevassed areas characteristic of a cirque glacier. [1]
The area and the glacier is usually covered in soft snow and is a popular area with tourists, snowboarders and ice climbers. [1]
Engineer Benjamin Morales Arnao, local glaciologist, has tested a method to reverse the thaw; cover the ice with a layer of sawdust 15 cm thick. The experiment was carried out on Mount Chaupijanca and Pastoruri. The first glacier managed to keep four meters of ice and the second kept five meters. "This material acts as an insulator. It contains cellulose and thus we managed to decrease the melting glacier. Although this method has worked well, we'll be testing other alternatives", said Morales. [3] "Those experiments curb glacial retreat on a small scale, but cannot bring ice blocks like Pastoruri back from the brink," said Selwyn Valverde with the Huascaran National Park, home to Pastoruri and more than 700 other shrinking Peruvian glaciers. "It's irreversible at this point," he said, adding that Pastoruri is no longer technically a glacier because it does not build up ice in the winter to release in the summer. "It's just loss, loss, loss now. It doesn't accumulate anymore." [4]
Greenland is located between the Arctic Ocean and the North Atlantic Ocean, northeast of Canada and northwest of Iceland. The territory comprises the island of Greenland—the largest island in the world—and more than a hundred other smaller islands. Greenland has a 1.2-kilometer-long (0.75 mi) border with Canada on Hans Island. A sparse population is confined to small settlements along certain sectors of the coast. Greenland possesses the world's second-largest ice sheet.
A glacier is a persistent body of dense ice that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as crevasses and seracs, as it slowly flows and deforms under stresses induced by its weight. As it moves, it abrades rock and debris from its substrate to create landforms such as cirques, moraines, or fjords. Although a glacier may flow into a body of water, it forms only on land and is distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water.
Glaciology is the scientific study of glaciers, or, more generally, ice and natural phenomena that involve ice.
The Aletsch Glacier or Great Aletsch Glacier is the largest glacier in the Alps. It has a length of about 23 km (14 mi) (2014), a volume of 15.4 km3 (3.7 cu mi) (2011), and covers about 81.7 km2 (2011) in the eastern Bernese Alps in the Swiss canton of Valais. The Aletsch Glacier is composed of four smaller glaciers converging at Konkordiaplatz, where its thickness was measured by the ETH to be still near 1 km (3,300 ft). It then continues towards the Rhône valley before giving birth to the Massa. The Aletsch Glacier is – like most glaciers in the world today – a retreating glacier. As of 2016, since 1980 it lost 1.3 kilometres (0.81 mi) of its length, since 1870 3.2 kilometres (2.0 mi), and lost also more than 300 metres (980 ft) of its thickness.
Gangotriglacier is located in Uttarkashi District, Uttarakhand, India in a region bordering Tibet. This glacier, one of the primary sources of the Ganges, has a volume of over 27 cubic kilometers. The glacier is about 30 kilometres long and 2 to 4 km wide. Around the glacier are the peaks of the Gangotri Group, including several peaks notable for extremely challenging climbing routes, such as Shivling, Thalay Sagar, Meru, and Bhagirathi III. It flows roughly northwest, originating in a cirque below Chaukhamba, the highest peak of the group.
An ice shelf is a large platform of glacial ice floating on the ocean, fed by one or multiple tributary glaciers. Ice shelves form along coastlines where the ice thickness is insufficient to displace the more dense surrounding ocean water. The boundary between the ice shelf (floating) and grounded ice is referred to as the grounding line; the boundary between the ice shelf and the open ocean is the ice front or calving front.
Jökulsárlón is a large glacial lake in southern part of Vatnajökull National Park, Iceland. Situated at the head of the Breiðamerkurjökull glacier, it developed into a lake after the glacier started receding from the edge of the Atlantic Ocean. The lake has grown since then at varying rates because of melting of the glaciers. The glacial front is now about 8 km (5.0 mi) away from the ocean's edge and the lake covers an area of about 18 km2 (6.9 sq mi). In 2009 it was reported to be the deepest lake in Iceland, at over 284 m (932 ft), as glacial retreat extended its boundaries. The size of the lake has increased fourfold since the 1970s.
Mendenhall Glacier is a glacier about 13.6 miles (21.9 km) long located in Mendenhall Valley, about 12 miles (19 km) from downtown Juneau in the southeast area of the U.S. state of Alaska. The glacier and surrounding landscape is protected as part of the 5,815 acres (2,353 ha) Mendenhall Glacier Recreation Area, a federally designated unit of the Tongass National Forest.
The Franz Josef Glacier is a 12-kilometre-long (7.5 mi) temperate maritime glacier in Westland Tai Poutini National Park on the West Coast of New Zealand's South Island. Together with the Fox Glacier 20 kilometres (12 mi) to the south, and a third glacier, it descends from the Southern Alps to less than 300 metres (980 ft) above sea level.
Tasman Glacier is the largest glacier in New Zealand, and one of several large glaciers which flow south and east towards the Mackenzie Basin from the Southern Alps in New Zealand's South Island.
Glacial motion is the motion of glaciers, which can be likened to rivers of ice. It has played an important role in sculpting many landscapes. Most lakes in the world occupy basins scoured out by glaciers. Glacial motion can be fast or slow, but is typically around 25 centimetres per day (9.8 in/d).
Thwaites Glacier is an unusually broad and vast Antarctic glacier located east of Mount Murphy, on the Walgreen Coast of Marie Byrd Land. It was initially sighted by polar researchers in 1940, mapped in 1959–1966 and officially named in 1967, after the late American glaciologist Fredrik T. Thwaites. The glacier flows into Pine Island Bay, part of the Amundsen Sea, at surface speeds which exceed 2 kilometres (1.2 mi) per year near its grounding line. Its fastest-flowing grounded ice is centered between 50 and 100 kilometres east of Mount Murphy. Like many other parts of the cryosphere, it has been adversely affected by climate change, and provides one of the more notable examples of the retreat of glaciers since 1850.
The Juneau Icefield is an ice field located just north of Juneau, Alaska, continuing north through the border with British Columbia, extending through an area of 3,900 square kilometres (1,500 sq mi) in the Coast Range ranging 140 km (87 mi) north to south and 75 km (47 mi) east to west. The icefield is the source of many glaciers, including the Mendenhall Glacier and the Taku Glacier. The icefield is home to over 40 large valley glaciers and 100 smaller ones. The Icefield serves as a tourist attraction with many travellers flown in by helicopter for quick walks on the 240-to-1,400-metre deep ice and the massive, awe-inspiring moist crevasses. The icefield, like many of its glaciers, reached its maximum glaciation point around 1700 and has been in retreat since. Much of the icefield is contained within the Tongass National Forest. Since 1948, the Juneau Icefield Research Program has monitored glaciers of the Juneau Icefield. On the west side of the icefield, from 1946-2009, the terminus of the Mendenhall Glacier has retreated over 700 metres (0.43 mi).
Crucial to the survival of a glacier is its mass balance of which surface mass balance (SMB), the difference between accumulation and ablation. Climate change may cause variations in both temperature and snowfall, causing changes in the surface mass balance. Changes in mass balance control a glacier's long-term behavior and are the most sensitive climate indicators on a glacier. From 1980 to 2012 the mean cumulative mass loss of glaciers reporting mass balance to the World Glacier Monitoring Service is −16 m. This includes 23 consecutive years of negative mass balances.
The retreat of glaciers since 1850 is well documented and is one of the effects of climate change. The retreat of mountain glaciers provide evidence for the rise in global temperatures since the late 19th century. Examples include mountain glaciers in western North America, Asia, the Alps in central Europe and tropical and subtropical regions of South America and Africa. Since glacial mass is affected by long-term climatic changes, e.g., precipitation, mean temperature, and cloud cover, glacial mass changes are one of the most sensitive indicators of climate change. Retreat of glaciers is also a major reason for sea level rise. Excluding peripheral glaciers of ice sheets, the total cumulated global glacial losses over the 26-year period from 1993 to 2018 were likely 5500 gigatons, or 210 gigatons per yr.
The Kongsvegen is a glacier, located in west Spitsbergen, Svalbard, 1,250 kilometres (780 mi) north of the Norwegian mainland.
Overdeepening is a characteristic of basins and valleys eroded by glaciers. An overdeepened valley profile is often eroded to depths which are hundreds of metres below the lowest continuous surface line along a valley or watercourse. This phenomenon is observed under modern day glaciers, in salt-water fjords and fresh-water lakes remaining after glaciers melt, as well as in tunnel valleys which are partially or totally filled with sediment. When the channel produced by a glacier is filled with debris, the subsurface geomorphic structure is found to be erosionally cut into bedrock and subsequently filled by sediments. These overdeepened cuts into bedrock structures can reach a depth of several hundred metres below the valley floor.
The Qori Kalis Glacier is a tropical glacier located in the Cordillera Oriental section of the Andes mountains of Peru. It is one of the few tropical glaciers left in the world, and is the main outlet of the Quelccaya Ice Cap.
The Quelccaya Ice Cap is the second largest glaciated area in the tropics, after Coropuna. Located in the Cordillera Oriental section of the Andes mountains in Peru, the cap covers an area of 42.8 square kilometres (16.5 sq mi) with ice up to 200 metres (660 ft) thick. It is surrounded by tall ice cliffs and a number of outlet glaciers, the largest of which is known as Qori Kalis Glacier; lakes, moraines, peat bogs and wetlands are also present. There is a rich flora and fauna, including birds that nest on the ice cap. Quelccaya is an important source of water, eventually melting and flowing into the Inambari and Vilcanota Rivers.
A glacier head is the top of a glacier. Although glaciers seem motionless to the observer they are in constant motion and the terminus is always either advancing or retreating.