A glacier is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. Glaciers slowly deform and flow under stresses induced by their weight, creating crevasses, seracs, and other distinguishing features. They also abrade rock and debris from their substrate to create landforms such as cirques, moraines, or fjords. Glaciers form only on land and are distinct from the much thinner sea ice and lake ice that forms on the surface of bodies of water.
The Territory of Heard Island and McDonald Islands (HIMI) is an Australian external territory comprising a volcanic group of mostly barren Antarctic islands, about two-thirds of the way from Madagascar to Antarctica. The group's overall size is 372 km2 (144 sq mi) in area and it has 101.9 km (63 mi) of coastline. Discovered in the mid-19th century, the islands lie on the Kerguelen Plateau in the Indian Ocean and have been an Australian territory since 1947. They contain Australia's only two active volcanoes. The summit of one, Mawson Peak, is higher than any mountain in all other Australian states or territories, except Dome Argus, Mount McClintock and Mount Menzies in the Australian Antarctic Territory.
The Alpine region of Switzerland, conventionally referred to as the Swiss Alps, represents a major natural feature of the country and is, along with the Swiss Plateau and the Swiss portion of the Jura Mountains, one of its three main physiographic regions. The Swiss Alps extend over both the Western Alps and the Eastern Alps, encompassing an area sometimes called Central Alps. While the northern ranges from the Bernese Alps to the Appenzell Alps are entirely in Switzerland, the southern ranges from the Mont Blanc massif to the Bernina massif are shared with other countries such as France, Italy, Austria and Liechtenstein.
An esker, eskar, eschar, or os, sometimes called an asar, osar, or serpent kame, is a long, winding ridge of stratified sand and gravel, examples of which occur in glaciated and formerly glaciated regions of Europe and North America. Eskers are frequently several kilometres long and, because of their uniform shape, look like railway embankments.
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), has about 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 Concordia Place, 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.
The McMurdo Dry Valleys are a row of largely snow-free valleys in Antarctica, located within Victoria Land west of McMurdo Sound. The Dry Valleys experience extremely low humidity and surrounding mountains prevent the flow of ice from nearby glaciers. The rocks here are granites and gneisses, and glacial tills dot this bedrock landscape, with loose gravel covering the ground. It is one of the driest places on Earth and has not seen rain for nearly 2 million years.
The Greenland ice sheet is a vast body of ice covering 1,710,000 square kilometres (660,000 sq mi), roughly near 80% of the surface of Greenland.
Periyar, IPA: [peɾijɐːr], is the longest river and the river with the largest discharge potential in the Indian state of Kerala. It is one of the few perennial rivers in the region and provides drinking water for several major towns. The Periyar is of utmost significance to the economy of Kerala. It generates a significant proportion of Kerala's electrical power via the Idukki Dam and flows along a region of industrial and commercial activity. The river also provides water for irrigation and domestic use throughout its course besides supporting a rich fishery. Due to these reasons, the river has been named the "Lifeline of Kerala". Kochi city, in the vicinity of the river mouth draws its water supply from Aluva, an upstream site sufficiently free of seawater intrusion. Twenty five percent of Kerala's industries are along the banks of river Periyar. These are mostly crowded within a stretch of 5 kilometres (3 mi) in the Eloor-Edayar region (Udhyogamandal), about 10 kilometres (6 mi) north of Kochi harbor.
Folgefonna is a collective term for three plateau glaciers in the Hardanger region of Vestland county, Norway. They are located on the Folgefonna peninsula in the municipalities of Ullensvang, Kvinnherad, and Etne. The three glaciers are:
Mertz Glacier is a heavily crevassed glacier in George V Coast of East Antarctica. It is the source of a glacial prominence that historically has extended northward into the Southern Ocean, the Mertz Glacial Tongue. It is named in honor of the Swiss explorer Xavier Mertz.
Svartisen is a collective term for two glaciers located in Nordland county in northern Norway. It is part of Saltfjellet-Svartisen National Park, located in the Saltfjell mountain range. The glaciers are located in the municipalities of Beiarn, Meløy, Rana, and Rødøy. Svartisen consists of two separate glaciers that are separated by the 1-kilometre (0.62 mi) long Vesterdalen valley. The two glaciers are:
The lake known as O'Higgins in Chile and San Martín in Argentina is located around coordinates 48°50′S72°36′W in Patagonia, between the Aysén del General Carlos Ibáñez del Campo Region and the Santa Cruz Province.
The retreat of glaciers since 1850 affects the availability of fresh water for irrigation and domestic use, mountain recreation, animals and plants that depend on glacier-melt, and, in the longer term, the level of the oceans. Deglaciation occurs naturally at the end of ice ages, but glaciologists find the current glacier retreat is accelerated by the measured increase of atmospheric greenhouse gases—an effect of climate change. Mid-latitude mountain ranges such as the Himalayas, Rockies, Alps, Cascades, and the southern Andes, as well as isolated tropical summits such as Mount Kilimanjaro in Africa, are showing some of the largest proportionate glacial losses. Excluding peripheral glaciers of ice sheets, total global glacial losses were likely 5500 gigatons over 1993–2018.
Flakavatnet is an alpine lake on the border of Vestland and Viken counties in Norway. The 3.43-square-kilometre (1.32 sq mi) lake lies in the municipalities of Ulvik and Hol and the lake lies entirely within the Hallingskarvet National Park. The village of Finse lies about 5 kilometres (3.1 mi) southwest of the lake.
Ablation zone or ablation area refers to the low-altitude area of a glacier or ice sheet below firn with a net loss in ice mass due to melting, sublimation, evaporation, ice calving, aeolian processes like blowing snow, avalanche, and any other ablation. The equilibrium line altitude (ELA) or snow line separates the ablation zone from the higher-altitude accumulation zone. The ablation zone often contains meltwater features such as supraglacial lakes, englacial streams, and subglacial lakes. Sediments dropped in the ablation zone forming small mounds or hillocks are called kames. Kame and kettle hole topography is useful in identifying an ablation zone of a glacier. The seasonally melting glacier deposits much sediment at its fringes in the ablation area. Ablation constitutes a key part of the glacier mass balance.
Kolka Glacier is a glacier in North Ossetia, Russia, near Mount Kazbek, known for its surging properties. The most recent and the most powerful surge took place on 20 September 2002, resulting in the death of ca. 140 people.
Bara Shigri is a glacier located in Lahaul & Spiti, Himachal Pradesh, India. It is currently extending to 27.7 kilometres and covers over 126.45 square kilometres. It is the largest glacier in Himachal Pradesh.
The geography of the Heard Island and McDonald Islands (HIMI) refers to the geography of Heard Island and the McDonald Islands, one of the most remote places on earth. The islands belong to Australia and are located 4,000 kilometres (2,485.5 mi) southwest of the mainland in the Southern Ocean. These subantarctic islands were transferred to Australia by the United Kingdom in 1947. They lie between Madagascar and Antarctica.
The Rapides River is a river in the Côte-Nord region of Quebec, Canada. It empties into the Gulf of Saint Lawrence.
