A lagoon is a shallow stretch of salt water partly or wholly separated from the sea by a narrow strip of land or a low sand-bank or coral reef. Research Lagoon
Lakes are accumulations of water in hollows on the earth's surface. When they are drained by rivers their waters are fresh, but when they have no outlet they are salty, e.g. the Dead Sea, Sea of Aral, etc.
Lakes may owe their origin to:
Barriers across a river valley hold back the water, which forms a lake. Such barriers may be of various types. (a) Sometimes artificial barriers of concrete and masonry are built across a valley so as to make a lake which can act as a reservoir for the water-supply of a large city, e.g. LakeVyrnwy for Liverpool. (b) A glacier may deposit a mass of morainic material across a valley. In this way the lakes of the Lake District and many of the Scottish lakes were formed. (c) A landslip may occur. A lake was formed thus in the Upper GangesValley in 1892. Two years later the landslip dam gave way, and disastrous floods occurred downstream. (d) Oxbow lakes are formed from the meanders of rivers. The deposition of silt at the two ends of the 'oxbow' closes the channel between the main river and its old loop. Many oxbow lakes border the River Murray in Australia, and the lower Mississippi. (e) Sometimes a lavastream may flow across a valley and cause the formation of a lake, e.g. LakeTaupo in New Zealand. (f) Sometimes large estuaries are partially filled with silt. In the portions not so filled are large shallow lagoons. Such lagoons are found in deltaic areas. The NorfolkBroads are portions of an old river estuary. (g) When a silt-laden stream enters a lake its speed is checked and a barrier or delta is built across the lake splitting it into two portions. This has happened in the Lake District, where Keswick stands in the alluvial flats between Lakes Bassenthwaite and Derwentwater, and in Switzerland, where Interlaken is situated in the flats between Lakes Thun and Brienz. (h) The action of the sea often causes an accumulation of sand and pebbles which cuts off a lagoon of sea water. The Fleet in Dorset is such a lagoon, cut off from the sea by Chesil Bank, a long pebble beach which joins Portland Island to the mainland.
The nehrungs of East Prussia are sand-spits which enclose the shallow salt-water lagoons or halls, such as Kurische Haff. Earth movements cause lakeformation when subsidence occurs. This is most easily seen in rift valleys. Examples of riftvalley lakes are the Dead Sea, Lakes Nyasa and Tanganyika in Africa, and LakeTorrens in Australia. These are all long, narrow, and very deep lakes.
In Cheshire, the removal of underground beds of salt has caused subsidence resulting in the 'meres' of the Weaver Valley. The 'folding' of the earth across the line of a river valley may partially block a river and help to form a lake. The study of a good physical map will reveal the connection between mountain building and the formation of LakeGeneva and LakeConstance in Switzerland. Where there are large areas of depressed lowland wide and shallow lakes are formed in the lowest part of the depression, for example the Sea of Aral in Asiatic Russia, LakeBalaton in Hungary, and LakeEyre in Australia. Ice sheets and valley glaciers may scoop out hollows to form 'rock basins'. Mountain tarns and corrie lakes in North Wales and Scotland have been formed in this way. Water also accumulates in the hollows of unevenly- distributed glacial drift. Such are the lakes of East Prussia, and also those of the Cheshire-Shropshire borders near Ellesmere. Subsidence of the land surface and consequent lakeformation may be directly related to volcanic action. Lough Neagh in Northern Ireland is a shallow lake formed by subsidence of this type. Lakes are often formed by the accumulation of water in the craters of extinct volcanoes, for example the Laachersee in the Eifel region of Germany. Research Lakes
The Red-throated Diver or Red-throated Loon (Gavia stellata) is a migratory sea bird found in Iceland, northern Scotland, Ireland, Scandinavia, Greenland, Murmansk and arctic North America, migrating as far south as the Mediterranean. It grows to a length of about 60 centimetres. The nest is built on the edge of a small but deep pool, coastal lagoon or lake and is made of sphagnum or other mosses and plant stems. Paired birds return to the same location each year to build a new nest, with two eggs being laid in May or June which both partners take turns to incubate for between 28 and 36 days. If a clutch of eggs is lost, the female will lay again. The Red-throated Diver feeds mainly on fish and also amphibians, crustaceans, molluscs, aquatic insects and worms. Research Red-Throated Diver
Richard Carlson was an American writer, actor and film director. He was born in 1912 at Albert Lea, Minnesota and died in 1977 of a cerebral hemorrhage. He starred in the 1954 film 'The Creature From The Black Lagoon'. Research Richard Carlson
Brooke Shields is an American actress. She was born in 1965 at New York. She started her career as a child model at the age of one, and her acting career in a commercial for soap, before becoming known when she starred in the film 'The Blue Lagoon' Research Brooke Shields
Kelly Preston (real name Kelly Kamalelehua Palzis) is an American actress and former model. She was born in 1962 at Honolulu, Hawaii. Kelly Preston was 'discovered' by a fashion photographer when she was sixteen and became a model. She auditioned for the starring role in the 1980 film 'The Blue Lagoon' but was rejecetd in gavour of Brooke Shields. In 1986 she married Kevin Gage, getting divorced two years later and marrying John Travolta in 1991 after which she decided to become a mother and housewife first, and an actress second. Research Kelly Preston
Milla Jovovich is a Ukranian actress, model and singer. She was born at Kiev in 1975. After starting modelling at the age of nine she made her film debut in the 1991 'Return To The Blue Lagoon'. Research Milla Jovovich
Abbreviations
Research Atoll
