Surge channel

A surge channel is a narrow inlet, usually on a rocky shoreline, and is formed by differential erosion of those rocks by coastal wave action.[1][2] As waves strike the shore, water fills the channel, and drains out again as the waves retreat. The narrow confines of the channel create powerful currents that reverse themselves rapidly as the water level rises and falls, and cause violent hydrodynamic mixing. However, there is relatively little exchange of water between channels; experimental studies and mathematical modelling of the coastline near Hopkins Marine Station in California have shown that water is rapidly mixed within each channel, but that it mostly moves in an oscillatory manner. Surge channels have been likened to 'containment vessels', retaining water borne gametes and probably enhancing the effectiveness of external fertilisation of marine species dwelling within them.[3][4]

Surge channels can form in reefs,[2]:14[5] and the term is sometimes also applied to breaches of coastal dunes by storms.[6][7]

Surge channels can range from a few inches across to 10 feet or more across. They may create tide pools if the conditions are correct, but the rapid water movement almost always creates a dangerous situation for people or animals that are caught in it.[8] The West Coast Trail on the coast of Vancouver Island, B.C., is known for its large number of surge channels, some of which are impassable even at low tide and must be crossed inland.[9][10]

Surge channel
Surge channel on the West Coast Trail, Vancouver Island.
Surge... (5651706021)
Surge channel at Cronulla, New South Wales

See also

References

  1. ^ Spellman, Frank R. (2010-03-16). Geography for Nongeographers. Government Institutes. p. 30. ISBN 9781605906874.
  2. ^ a b Light, Sol Felty (2007). The Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon. University of California Press. ISBN 9780520239395.
  3. ^ Denny, Mark; Diariki, Jeff; Distefano, Sandra (October 1992). "Biological Consequences of Topography on Wave-swept Rocky Shores: I. Enhancement of External Fertilization". Biological Bulletin. 183 (2): 220.
  4. ^ Levin, Simon A.; Powell, Thomas M.; Steele, John H. (1993). Patch Dynamics. Springer Science & Business Media. p. 54. ISBN 9783642501555.
  5. ^ Karleskint, George; Turner, Richard; Small, James (2013). Introduction to Marine Biology. Belmont, California: Cengage Learning. pp. 403–404. ISBN 1133364462.
  6. ^ Kusky, Timothy M. (2003). Geological Hazards: A Sourcebook. Greenwood Publishing Group. p. 155. ISBN 9781573564694.
  7. ^ Kusky, Timothy M. (2008). The Coast: Hazardous Interactions Within the Coastal Environment. Infobase Publishing. p. 56. ISBN 9780816064670.
  8. ^ "Surge Channels". coastsmart.ca. CoastSmart. Retrieved 25 July 2018.
  9. ^ Leadem, Tim (2015). Hiking the West Coast of Vancouver Island: An Updated and Comprehensive Guide to All Major Trails. Greystone Books Ltd. pp. 58, 66, 117, 146–147. ISBN 9781771641463.
  10. ^ "West Coast Trail Map" (PDF). Pacific Rim National Park Reserve. Retrieved 25 July 2018.
British Academy Television Awards 2008

The 2008 British Academy Television Awards were held on 20 April at the London Palladium Theatre in London. The ceremony was broadcast live on BBC One in the United Kingdom. The nominations were announced on 18 March 2008. Drama Cranford received the most nominations with four, making Judi Dench the most nominated actress in BAFTA history for her work on TV and film combined. Long-running soap opera Coronation Street failed to earn a nomination, for the first time in ten years. Bruce Forsyth received the Academy Fellowship Award.Winners in bold.

Channel (geography)

In physical geography, a channel is a type of landform consisting of the outline of a path of relatively shallow and narrow body of fluid, most commonly the confine of a river, river delta or strait. The word is cognate to canal, and sometimes shows in this form, e.g. the Hood Canal.

Coast

The coast, also known as the coastline or seashore, is the area where land meets the sea or ocean, or a line that forms the boundary between the land and the ocean or a lake. A precise line that can be called a coastline cannot be determined due to the coastline paradox.

The term coastal zone is a region where interaction of the sea and land processes occurs. Both the terms coast and coastal are often used to describe a geographic location or region (e.g., New Zealand's West Coast, or the East and West Coasts of the United States). Edinburgh is an example city on the coast of Great Britain.

The term pelagic coast refers to a coast that fronts the open ocean, as opposed to a more sheltered coast in a gulf or bay. A shore, on the other hand, can refer to parts of land adjoining any large body of water, including oceans (seashore) and lakes (lake shore). Similarly, the somewhat related term stream bed or stream bank refers to the land alongside or sloping down to a river (riverbank) or body of water smaller than a lake. Bank is also used in some parts of the world to refer to an artificial ridge of earth intended to retain the water of a river or pond; in other places this may be called a levee.

While many scientific experts might agree on a common definition of the term coast, the delineation of the extents of a coast differ according to jurisdiction, with many scientific and government authorities in various countries differing for economic and social policy reasons. According to the UN atlas, 44% of people live within 150 km (93 mi) of the sea.

Coastal geography

Coastal geography is the study of the constantly changing region between the ocean and the land, incorporating both the physical geography (i.e. coastal geomorphology, geology and oceanography) and the human geography (sociology and history) of the coast. It includes understanding coastal weathering processes, particularly wave action, sediment movement and weather, and the ways in which humans interact with the coast

Island

An island or isle is any piece of sub-continental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, skerries, cays or keys. An island in a river or a lake island may be called an eyot or ait, and a small island off the coast may be called a holm. A grouping of geographically or geologically related islands is called an archipelago, such as the Philippines.

An island may be described as such, despite the presence of an artificial land bridge; examples are Singapore and its causeway, and the various Dutch delta islands, such as IJsselmonde. Some places may even retain "island" in their names for historical reasons after being connected to a larger landmass by a land bridge or landfill, such as Coney Island and Coronado Island, though these are, strictly speaking, tied islands. Conversely, when a piece of land is separated from the mainland by a man-made canal, for example the Peloponnese by the Corinth Canal or Marble Hill in northern Manhattan during the time between the building of the United States Ship Canal and the filling-in of the Harlem River which surrounded the area, it is generally not considered an island.

There are two main types of islands in the sea: continental and oceanic. There are also artificial islands.

List of landforms

Landforms are categorised by characteristic physical attributes such as elevation, slope, orientation, rock exposure, and soil type.

Mudflat

Mudflats or mud flats, also known as tidal flats, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A recent global analysis suggested they are as extensive globally as mangroves. They are found in sheltered areas such as bays, bayous, lagoons, and estuaries. Mudflats may be viewed geologically as exposed layers of bay mud, resulting from deposition of estuarine silts, clays and marine animal detritus. Most of the sediment within a mudflat is within the intertidal zone, and thus the flat is submerged and exposed approximately twice daily.

In the past tidal flats were considered unhealthy, economically unimportant areas and were often dredged and developed into agricultural land. Several especially shallow mudflat areas, such as the Wadden Sea, are now popular among those practising the sport of mudflat hiking.

On the Baltic Sea coast of Germany in places, mudflats are exposed not by tidal action, but by wind-action driving water away from the shallows into the sea. These wind-affected mudflats are called windwatts in German.

Outline of oceanography

The following outline is provided as an overview of and introduction to Oceanography.

Surf zone

As ocean surface waves come closer to shore they break, forming the foamy, bubbly surface called surf. The region of breaking waves defines the surf zone. After breaking in the surf zone, the waves (now reduced in height) continue to move in, and they run up onto the sloping front of the beach, forming an uprush of water called swash. The water then runs back again as backswash. The nearshore zone where wave water comes onto the beach is the surf zone. The water in the surf zone, or breaker zone, is shallow, usually between 5 and 10 m (16 and 33 ft) deep; this causes the waves to be unstable.

Landforms
Beaches
Processes
Management
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