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A23a
A23a is a large tabular iceberg which calved from the Filchner–Ronne Ice Shelf in 1986. It was then stuck on the sea bed for many years but then started moving in 2020. Its area is about , which made it one of the largest icebergs in the world until it was temporarily surpassed in size by A76. In November 2023, A23a was tracked moving past the northern tip of the Antarctic Peninsula and headed toward the Southern Ocean. On 1 December 2023, the iceberg was intercepted by the polar research ship RRS ''Sir David Attenborough'', off the tip of the Antarctic Peninsula. At 10 knots, it took the ship several hours to sail along two sides of the iceberg. The iceberg is expected to release a significant quantity of mineral dust as it melts and so the ship took water samples around its perimeter. On 14 January 2024, dramatic archways caused by wave action on A23a were documented by a drone operated by Eyos Expeditions videographer Richard Sidey and expedition leader Ian Strachan. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Druzhnaya Station
Druzhnaya Station is any one of four different Antarctic research stations operated by the Soviet Union and later Russia from 1976 to 2013. Druzhnaya I Druzhnaya I was established in 1975 as seasonal field camps on the Filchner Ice Shelf to carry out topographic and geodetic mapping of the local area. In 1986, satellite images revealed ice breakup near Druzhnaya I. It drifted to sea in 1986 when the ice it was on broke from the main ice shelf as iceberg A23a. It was later discovered at sea by the ship Kapitan Kondratyev. Its equipment and prefabricated structures were airlifted to the recently constructed Druzhnaya III. Druzhnaya II Druzhnaya II was a temporary field camp that operated from January 13 to February 21, 1982, on the Ronne Ice Shelf. It supported in the carrying out of radar sounding of the ice shelf. Druzhnaya III Druzhnaya III was established in 1987 near Cape Norvegia. The station was constructed in two weeks. Kapitan Kondratyev offloaded materials fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iceberg A23a From 2011 To 2023
An iceberg is a piece of freshwater ice more than 15 m long that has broken off a glacier or an ice shelf and is floating freely in open (salt) water. Smaller chunks of floating glacially-derived ice are called "growlers" or "bergy bits". The sinking of the ''Titanic'' in 1912 led to the formation of the International Ice Patrol in 1914. Much of an iceberg is below the surface, which led to the expression "tip of the iceberg" to illustrate a small part of a larger unseen issue. Icebergs are considered a serious maritime hazard. Icebergs vary considerably in size and shape. Icebergs that calve from glaciers in Greenland are often irregularly shaped while Antarctic ice shelves often produce large tabular (table top) icebergs. The largest iceberg in recent history (2000), named B-15, measured nearly 300 km × 40 km. The largest iceberg on record was an Antarctic tabular iceberg of over [] sighted west of Scott Island, in the South Pacific Ocean, by the USS Glacier ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iceberg
An iceberg is a piece of freshwater ice more than 15 m long that has broken off a glacier or an ice shelf and is floating freely in open (salt) water. Smaller chunks of floating glacially-derived ice are called "growlers" or "bergy bits". The sinking of the ''Titanic'' in 1912 led to the formation of the International Ice Patrol in 1914. Much of an iceberg is below the surface, which led to the expression " tip of the iceberg" to illustrate a small part of a larger unseen issue. Icebergs are considered a serious maritime hazard. Icebergs vary considerably in size and shape. Icebergs that calve from glaciers in Greenland are often irregularly shaped while Antarctic ice shelves often produce large tabular (table top) icebergs. The largest iceberg in recent history (2000), named B-15, measured nearly 300 km × 40 km. The largest iceberg on record was an Antarctic tabular iceberg of over [] sighted west of Scott Island, in the South Pacific Ocean, by the USS Gla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Calving
Ice calving, also known as glacier calving or iceberg calving, is the breaking of ice chunks from the edge of a glacier.Essentials of Geology, 3rd edition, Stephen Marshak It is a form of ice ablation or ice disruption. It is the sudden release and breaking away of a mass of ice from a glacier, iceberg, ice front, ice shelf, or crevasse. The ice that breaks away can be classified as an iceberg, but may also be a growler, bergy bit, or a crevasse wall breakaway.Glossary of Glacier Terms Ellin Beltz, 2006. Retrieved July 2009. Calving of glaciers is often accompanied by a loud cracking or booming sound before blocks of ice up to high break loose and crash into the water. The entry of the ice into the water causes large, and often hazardous waves. The waves formed in locations like [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filchner–Ronne Ice Shelf
The Filchner-Ronne Ice Shelf, also known as Ronne-Filchner Ice Shelf, is an Antarctic ice shelf bordering the Weddell Sea. Description The seaward side of the Filchner-Ronne ice shelf is divided into Eastern (Filchner) and the larger Western (Ronne) sections by Berkner Island. The whole ice shelf covers some 430,000 km2, making it the second largest ice shelf in Antarctica (and on Earth), after the Ross Ice Shelf. It grows perpetually due to a flow of inland ice sheets. From time to time, when the shearing stresses exceed the strength of the ice, cracks form and large parts of the ice sheet separate from the ice shelf and float off and disperse as icebergs. This is known as calving. The Ronne ice shelf is the larger and western part of the Filchner-Ronne ice shelf. It is bounded on the west by the base of the Antarctic Peninsula (Graham Land with Zumberge Coast and Orville Coast) and Ellsworth Land. Commander Finn Ronne, USNR, leader of the Ronne Antarctic Research ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iceberg A-76
An iceberg is a piece of freshwater ice more than 15 m long that has broken off a glacier or an ice shelf and is floating freely in open (salt) water. Smaller chunks of floating glacially-derived ice are called "growlers" or "bergy bits". The sinking of the ''Titanic'' in 1912 led to the formation of the International Ice Patrol in 1914. Much of an iceberg is below the surface, which led to the expression "tip of the iceberg" to illustrate a small part of a larger unseen issue. Icebergs are considered a serious maritime hazard. Icebergs vary considerably in size and shape. Icebergs that calve from glaciers in Greenland are often irregularly shaped while Antarctic ice shelves often produce large tabular (table top) icebergs. The largest iceberg in recent history (2000), named B-15, measured nearly 300 km × 40 km. The largest iceberg on record was an Antarctic tabular iceberg of over [] sighted west of Scott Island, in the South Pacific Ocean, by the USS Glacier ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctic Peninsula
The Antarctic Peninsula, known as O'Higgins Land in Chile and Tierra de San Martín in Argentina, and originally as Graham Land in the United Kingdom and the Palmer Peninsula in the United States, is the northernmost part of mainland Antarctica. The Antarctic Peninsula is part of the larger peninsula of West Antarctica, protruding from a line between Cape Adams (Weddell Sea) and a point on the mainland south of the Eklund Islands. Beneath the ice sheet that covers it, the Antarctic Peninsula consists of a string of bedrock islands; these are separated by deep channels whose bottoms lie at depths considerably below current sea level. They are joined by a grounded ice sheet. Tierra del Fuego, the southernmost tip of South America, is about away across the Drake Passage. The Antarctic Peninsula is in area and 80% ice-covered. The marine ecosystem around the western continental shelf of the Antarctic Peninsula (WAP) has been subjected to rapid climate change. Over the past ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southern Ocean
The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the World Ocean, generally taken to be south of 60° S latitude and encircling Antarctica. With a size of , it is regarded as the second-smallest of the five principal oceanic divisions: smaller than the Pacific, Atlantic, and Indian oceans but larger than the Arctic Ocean. Over the past 30 years, the Southern Ocean has been subject to rapid climate change, which has led to changes in the marine ecosystem. By way of his voyages in the 1770s, James Cook proved that waters encompassed the southern latitudes of the globe. Since then, geographers have disagreed on the Southern Ocean's northern boundary or even existence, considering the waters as various parts of the Pacific, Atlantic, and Indian oceans, instead. However, according to Commodore John Leech of the International Hydrographic Organization (IHO), recent oceanographic research has discovered the importance of Southe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RRS Sir David Attenborough
RRS ''Sir David Attenborough'' is a research vessel owned by the Natural Environment Research Council and operated by the British Antarctic Survey for the purposes of both research and logistic support. The ship replaces a pair of existing vessels, and . The vessel is named after broadcaster and naturalist Sir David Attenborough. Background In 2014, the UK Government announced funding for the construction of a new polar research vessel for the British Antarctic Survey (BAS) to replace a pair of existing ships. This new ship was intended not only to be fully equipped with the latest instrumentation for the purposes of carrying out research in polar regions, for which it would have an improved icebreaking capability and greater endurance over the existing polar research vessel, but also to serve as a logistic support vessel for BAS teams in inshore locations. BAS contracted Houlder Ltd to undertake the basic design in which suggestions for the final configuration of the new sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knot (unit)
The knot () is a unit of speed equal to one nautical mile per hour, exactly (approximately or ). The ISO standard symbol for the knot is kn. The same symbol is preferred by the Institute of Electrical and Electronics Engineers ( IEEE), while kt is also common, especially in aviation, where it is the form recommended by the International Civil Aviation Organization (ICAO). The knot is a non- SI unit. The knot is used in meteorology, and in maritime and air navigation. A vessel travelling at 1 knot along a meridian travels approximately one minute of geographic latitude in one hour. Definitions ;1 international knot = :1 nautical mile per hour (by definition), : (exactly), : (approximately), : (approximately), : (approximately) : (approximately). The length of the internationally agreed nautical mile is . The US adopted the international definition in 1954, having previously used the US nautical mile (). The UK adopted the international nautical mile definition in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineral Dust
Mineral dust is atmospheric aerosol originated from the suspension of minerals constituting the soil, composed of various oxides and carbonates. Human activities lead to 30% of the airborne dust load in the atmosphere. The Sahara Desert is the major source of mineral dust, which subsequently spreads across the Mediterranean (where it is the origin of rain dust) and Caribbean seas into northern South America, Central America, and eastern North America, and Europe. Additionally, it plays a significant role in the nutrient inflow to the Amazon rainforest. The Gobi Desert is another source of dust in the atmosphere, which affects eastern Asia and western North America. Characteristics Mineral dust is mainly constituted of the oxides (SiO2, Al2O3, FeO, Fe2O3, CaO, and others) and carbonates (CaCO3, MgCO3) that constitute the Earth's crust. Global mineral dust emissions are estimated at 1000-5000 million tons per year, of which the largest part is attributed to deserts. Alth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA Earth Observatory
NASA Earth Observatory is an online publishing outlet for NASA which was created in 1999. It is the principal source of satellite imagery and other scientific information pertaining to the climate and the environment which are being provided by NASA for consumption by the general public. It is funded with public money, as authorized by the United States Congress, and is part of the EOS Project Science Office located at Goddard Space Flight Center. , NASA Earth Observatory has won the Webby People's Voice Award in Education three times. There were a series of publicized images issued by the website in 2008, including imagery of clouds streaming over the Caspian Sea, dust storms curling off the coast of Morocco, the crumbling of the Wilkins Ice Shelf, Hurricane Bertha, and others. See also * Earth observation ** Earth observation satellite * Space exploration Space exploration is the use of astronomy and space technology to explore outer space. While the exploration ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
