| Abbot Ice Shelf' | |
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 Abbot Ice Shelf, MODIS image from 10 March 2003, 14:50 | |
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| Coordinates | 72°45′S 96°00′W / 72.750°S 96.000°W |
The Abbot Ice Shelf (72°45′S 96°00′W / 72.750°S 96.000°W) is an ice shelf 250 nautical miles (460 km; 290 mi) long and 40 nautical miles (74 km; 46 mi) wide, bordering Eights Coast from Cape Waite to Pfrogner Point in Antarctica. Thurston Island lies along the northern edge of the western half of this ice shelf; other sizable islands (Sherman Island, Carpenter Island, Dustin Island, Johnson Island, McNamara Island, Farwell Island and Dendtler Island) lie partly or wholly within this shelf.[1]
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The Blackwater estuary: change (1/4)
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Transcription
The Blackwater estuary on the coast of Essex. A place where land meets sea and human and natural processes interact. The estuary forms an environment of diverse habitats and species and is an area used in a variety of ways. It's a flatland of marshes, creeks and mudflats, used for fishing, farming and recreation. But it's the relationship between the sea and the land that is fundamental. A relationship that may at first seem predictable, until nature unleashes a freaky bent which can upset the whole balance. By looking more closely at this relationship, we can begin to understand the themes of change, contest and response that enable us to explore the environment. The first of these, the theme of change, emphasises the dynamic relationship between land and sea over time. Well, talking about change, if we just look the last 100 years, the last two generations of people, they would have seen, first of all, a salt marsh out here and not sea. Then the salt marsh washed away and it became a mudflat. Then the mudflat went and it became a beach. These changes are talking place all the time. Change is the order of the day. Change is what coasts are about. When people look at a coastline like this, they think that it's always been the same, that this is static. In actual fact, only 10,000 years ago, a microsecond of geological time, this was part of a fresh-water system with the Thames, the Thames sweeps up here. If we go forward in time from then, from those big changes at the end of the last Ice age, if we went out there now and we went out a mile on that mud, when the tide goes down, you can go a mile out, you'll come across 4,000-year-old oak forests when it was dry land. 400 year ago, this bit of sea, which is right by the beach, had sheep grazing on it. Then we come to the 14th century, the mini Ice age came. The sea level has stopped rising, all the static. That's when all the sea walls went in. It's during that period that man realised the importance of using its coast, particularly for agricultural gain. At the mouth of the Blackwater is a 7th-century Saxon chapel of St Peter, itself on the site of a Roman fort. Here, Kevin Bruce describes the impact of humans on the local landscape. The most significant factor in this has been human changes. It's been the desire of man to reclaim natural salt marsh for agricultural purposes. So the landscape that we have here is very much a man-made landscape. The farmers found it beneficial to reclaim the land here because previous than building any sea walls at all, twice a day the saltings would have been flooded by the tides. They found these saltings extremely good for pasturing sheep and Doomsday Book records that hundreds of sheep were kept on the Essex's marshes, all round the Essex coast. And from the Middle Ages, right up to the 19th century, more and more land was being recovered from the sea. It's been a constant process. What these farmers discovered on building a new sea wall, then they changed the tidal patterns. The sea was beginning to slow down and enable deposition to take place further out on the saltings. It's actually recorded in many of the documents. The farmers reckon that within five or ten years of building a sea wall, there will be new, fresh saltings for them to enclose. So, bit by bit, they must have pushed out the level of the saltings and when they found it convenient, they would enclose them to produce new land. You can actually see from the maps how far the saltings extended. But once the sea level began to rise, the situation changed again. As time went on and the mini Ice age ended, in about 1860, this coastline here, which would have been salt marshes by now, because the sea's come up a bit... There was no beach here then. In fact, this beach, in the 1930s, was a little tiny, narrow strip. As the mud is washed away, the coarse material gets washed ashore and forms these beaches. Then behind us we get these rebeds forming. You have to bear in mind, in between the rebed there, and the trees behind it and the houses on the top, that cliff was a sea cliff in Saxon times. The sea level is always going up and down since the end of the last Ice age but with a steady and consistent trend upwards and you can't stop that.
Location
The Abbott Ice Shelf extends to the south of Thurston Island, Dustin Island, McNamara Island, and Farwell Island all of which lie between the ice shelf and the Bellingshausen Sea. It occupies the whole of Peacock Sound in its western part. The Demas Ice Tongue extends into the Amundsen Sea from the west end of the ice shelf. Islands embedded in the bbott Ice Shelf include the Trice Islands, Sherman Island, Carpenter Island, Johnson Island, Lepley Nunatak and Dendtler Island. It is to the north of King Peninsula and Jones Mountains on the Eights Coast, Cape Waite on King Peninsula lies at its western end, and Pfrogner Point on Fletcher Peninsula is at its eastern end. Fletcher Peninsula separates it from the Venable Ice Shelf to the east.[2]
Discovery and name
The Abbot Ice Shelf shelf was sighted by members of the United States Antarctic Service in flights from the ship Bear, in February 1940. Its western portion was delineated from air photos taken by the United States Navy (USN) Operation Highjump, 1946–47. The full extent was mapped by the United States Geological Survey (USGS) from USN air photos of 1966. It was named by the United States Advisory Committee on Antarctic Names (US-ACAN) for Rear Admiral James Lloyd Abbot Jr., Commanding Officer, U.S. Naval Support Force, Antarctica, February 1967 to June 1969.[1]
Features
Peacock Sound
72°45′S 99°00′W / 72.750°S 99.000°W. An ice-filled sound, 135 nautical miles (250 km; 155 mi) long and 40 nautical miles (74 km; 46 mi) wide, separating Thurston Island from the Eights Coast. The sound is not navigable by ships, it being occupied by the western part of Abbot Ice Shelf. The feature was discovered by members of the USAS in flights from the ship Bear in February 1940, and was further delineated from air photos taken by United States Navy Operation Highjump in December 1946. The sound was first noted to parallel the entire south coast of Thurston Island, thereby establishing insularity, by the United States Navy Bellingshausen Sea Expedition in February 1960. Named after the sloop of war Peacock in which Captain William L. Hudson, in company with the tender Flying Fish under Lieutenant William M. Walker, both of the USEE, 1838-42, sailed along the edge of the pack ice to the north of Thurston Island for several days in March 1839.[3]
Farwell Island
72°49′S 91°10′W / 72.817°S 91.167°W. An ice-covered island, about 38 nautical miles (70 km; 44 mi) long and 10 nautical miles (19 km; 12 mi) wide, lying between McNamara and Dendtler Islands in the east part of Abbot Ice Shelf. The feature was positioned by parties from the USS Glacier and Stolen Island in February 1961, and was mapped by USGS from United States Navy air photos of 1966. Named by US-ACAN for Captain A.F. Farwell, Chief of Staff to the Commander, United States Naval Support Force, Antarctica, during Deep Freeze 1968 and 1969.[4]
Sherman Island
72°38′S 100°00′W / 72.633°S 100.000°W. An ice-covered island about 32 nautical miles (59 km; 37 mi) long and 10 nautical miles (19 km; 12 mi) wide, lying south of Thurston Island in the middle of Peacock Sound. The feature rises above Abbot Ice Shelf which occupies the sound. Delineated from aerial photographs taken by United States Navy OpHjp in December 1946. Named by US-ACAN for Admiral Forrest Sherman, United States Navy, Chief of Naval Operations, 1949-51, when preparations were being made for United States Naval support during the forthcoming IGY operations.[5]
Trice Islands
72°25′S 99°48′W / 72.417°S 99.800°W. A group of small ice-covered islands lying just west of Evans Point. The group rises above the general level of Abbot Ice Shelf which occupies the sound. First mapped from air photos taken by United States Navy OpHjp, .1946-47. Named by US-ACAN for Jack L. Trice, meteorologist at Byrd Station, 1964-65.[6]
Carpenter Island
72°39′S 98°03′W / 72.650°S 98.050°W. An oval-shaped island, 7 nautical miles (13 km; 8.1 mi) long, within the Abbot Ice Shelf of Peacock Sound. It lies 17 nautical miles (31 km; 20 mi) due east of Sherman Island. Mapped by USGS from surveys and United States Navy air photos, 1960-66. Named by US-ACAN for Donald L. Carpenter, radio scientist at Byrd Station, 1966-67.[7]
Johnson Island
72°51′S 93°55′W / 72.850°S 93.917°W. An ice-covered island, about 9 nautical miles (17 km; 10 mi) long and 5 nautical miles (9.3 km; 5.8 mi) wide, lying within Abbot Ice Shelf, about 14 nautical miles (26 km; 16 mi) southeast of Dustin Island. The feature was observed and roughly positioned as an "ice rise" by parties from the USS Glacier in February 1961. Remapped by USGS from United States Navy air photos, 1966. Named by US-ACAN for Theodore L. Johnson, electrical engineer at Byrd Station, 1964-65.[8]
Lepley Nunatak
73°07′S 90°23′W / 73.117°S 90.383°W. A small conspicuous rocky nunatak 2 nautical miles (3.7 km; 2.3 mi) southwest of Dentler Island, lying near the inner part and east end of Abbot Ice Shelf. First sighted on February 9, 1961 from helicopters of the USS Glacier and Staten Island. Named by US-ACAN for Larry K. Lepley, oceanographer of the United States Navy Hydrographic Office, who with three others was marooned at this nunatak, February 12-15, 1961, by a severe wind and snowstorm.[9]
Dendtler Island
72°58′S 89°57′W / 72.967°S 89.950°W. An ice-covered island, 14 nautical miles (26 km; 16 mi) long, lying in the east part of Abbot Ice Shelf between Farwell Island and Fletcher Peninsula. Mapped by USGS from surveys and United States Navy air photos, 1960-66. Named by US-ACAN for Major Robert Dendtler, United States Army, coordinating officer on the staff of the Commander, United States Navy Support Force, Antarctica, during Deep Freeze 1967 and 1968.[10]
Demas Ice Tongue
72°22′S 103°20′W / 72.367°S 103.333°W. Conspicuous ice tongue, about 20 nautical miles (37 km; 23 mi) long, extending west from Abbot Ice Shelf of Peacock Sound into the Amundsen Sea. Discovered by members of the USAS in flights from the Bear, February 1940, and named after E.J. Demas (d. 1979), member of the ByrdAE of 1928-30 and 1933-35.[11]
References
- ^ a b Alberts 1995, p. 1.
- ^ Thurston Island to Jones USGS.
- ^ Alberts 1995, p. 562.
- ^ Alberts 1995, p. 234.
- ^ Alberts 1995, p. 670.
- ^ Alberts 1995, p. 758.
- ^ Alberts 1995, p. 120.
- ^ Alberts 1995, p. 374.
- ^ Alberts 1995, p. 429.
- ^ Alberts 1995, p. 183.
- ^ Alberts 1995, p. 182.
Sources
- Alberts, Fred G., ed. (1995), Geographic Names of the Antarctic (PDF) (2 ed.), United States Board on Geographic Names, retrieved 3 December 2023
This article incorporates public domain material from websites or documents of the United States Board on Geographic Names. - Thurston Island to Jones Mountains (PDF), USGS: United States Geological Survey, retrieved 16 April 2024
- This article incorporates public domain material from websites or documents of the United States Geological Survey.
This page was last edited on 21 April 2024, at 12:03