Surge channel

Last updated

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

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]

Hopkins Marine Station is the marine laboratory of Stanford University. It is located ninety miles south of the university's main campus, in Pacific Grove, California on the Monterey Peninsula, adjacent to the Monterey Bay Aquarium. It is home to nine research laboratories and a fluctuating population of graduate and undergraduate students. It has also been used for archaeological exploration including that of the Chinese-American fishing village that existed on the site before being burnt down.

California State of the United States of America

California is a state in the Pacific Region of the United States. With 39.6 million residents, California is the most populous U.S. state and the third-largest by area. The state capital is Sacramento. The Greater Los Angeles Area and the San Francisco Bay Area are the nation's second and fifth most populous urban regions, with 18.7 million and 8.8 million residents respectively. Los Angeles is California's most populous city, and the country's second most populous, after New York. California also has the nation's most populous county, Los Angeles County, and its largest county by area, San Bernardino County. The City and County of San Francisco is both the country's second-most densely populated major city after New York and the fifth-most densely populated county, behind only four of the five New York City boroughs.

Gamete haploid cell that fuses with another haploid cell during fertilization (conception) in organisms that sexually reproduce

A gamete is a haploid cell that fuses with another haploid cell during fertilization (conception) in organisms that sexually reproduce. In species that produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female is any individual that produces the larger type of gamete—called an ovum —and a male produces the smaller tadpole-like type—called a sperm. In short a gamete is an egg or a sperm. This is an example of anisogamy or heterogamy, the condition in which females and males produce gametes of different sizes. In contrast, isogamy is the state of gametes from both sexes being the same size and shape, and given arbitrary designators for mating type. The name gamete was introduced by the Austrian biologist Gregor Mendel. Gametes carry half the genetic information of an individual, one ploidy of each type, and are created through meiosis.

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]

Reef A bar of rock, sand, coral or similar material, lying beneath the surface of water

A reef is a bar of rock, sand, coral or similar material, lying beneath the surface of water. Many reefs result from abiotic processes, but the best known reefs are the coral reefs of tropical waters developed through biotic processes dominated by corals and coralline algae.

Dune A hill of loose sand built by aeolian processes or the flow of water

In physical geography, a dune is a hill of loose sand built by aeolian processes (wind) or the flow of water. Dunes occur in different shapes and sizes, formed by interaction with the flow of air or water. Most kinds of dunes are longer on the stoss (upflow) side, where the sand is pushed up the dune, and have a shorter "slip face" in the lee side. The valley or trough between dunes is called a slack. A "dune field" or erg is an area covered by extensive dunes.

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]

West Coast Trail

The West Coast Trail, originally called the Dominion Lifesaving Trail, is a 75 km (47 mi) backpacking trail following the southwestern edge of Vancouver Island in British Columbia, Canada. It was built in 1907 to facilitate the rescue of shipwrecked survivors along the coast, part of the treacherous Graveyard of the Pacific. It is now part of the Pacific Rim National Park and is often rated by hiking guides as one of the world's top hiking trails.

Vancouver Island Island on the western coast of Canada

Vancouver Island is in the northeastern Pacific Ocean. It is part of the Canadian province of British Columbia. The island is 460 kilometres (290 mi) in length, 100 kilometres (62 mi) in width at its widest point, and 32,134 km2 (12,407 sq mi) in area. It is the largest island on the West Coast of North America.

See also

Related Research Articles

Coast Area where land meets the sea or ocean

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.

Beach Area of loose particles at the edge of the sea or other body of water

A beach is a landform alongside a body of water which consists of loose particles. The particles composing a beach are typically made from rock, such as sand, gravel, shingle, pebbles. The particles can also be biological in origin, such as mollusc shells or coralline algae.

Lagoon A shallow body of water separated from a larger body of water by barrier islands or reefs

A lagoon is a shallow body of water separated from a larger body of water by barrier islands or reefs. Lagoons are commonly divided into coastal lagoons and atoll lagoons. They have also been identified as occurring on mixed-sand and gravel coastlines. There is an overlap between bodies of water classified as coastal lagoons and bodies of water classified as estuaries. Lagoons are common coastal features around many parts of the world.

Wave-cut platform The narrow flat area often found at the base of a sea cliff or along the shoreline of a lake, bay, or sea that was created by erosion

A wave-cut platform, shore platform, coastal bench, or wave-cut cliff is the narrow flat area often found at the base of a sea cliff or along the shoreline of a lake, bay, or sea that was created by erosion. Wave-cut platforms are often most obvious at low tide when they become visible as huge areas of flat rock. Sometimes the landward side of the platform is covered by sand, forming the beach, and then the platform can only be identified at low tides or when storms move the sand.

A storm surge, storm flood or storm tide is a coastal flood or tsunami-like phenomenon of rising water commonly associated with low pressure weather systems, the severity of which is affected by the shallowness and orientation of the water body relative to storm path, as well as the timing of tides. Most casualties during tropical cyclones occur as the result of storm surges. It is a measure of the rise of water beyond what would be expected by the normal movement related to tides.

Asilomar State Beach state park in California

Asilomar State Beach is a state park unit of California, USA, providing public access to rocky coast and dune habitat on the Monterey Peninsula. The property includes the Asilomar Conference Grounds, a conference center built by the YWCA in 1913 that is now a National Historic Landmark. The 107-acre (43 ha) site is located in Pacific Grove and offers overnight lodging and views of the forest, surf and sand.

Littoral zone Part of a sea, lake or river that is close to the shore

The littoral zone or nearshore is the part of a sea, lake or river which is close to the shore. In coastal environments the littoral zone extends from the high water mark, which is rarely inundated, to shoreline areas that are permanently submerged. It always includes this intertidal zone and is often used to mean the same as the intertidal zone. However, the meaning of "littoral zone" can extend well beyond the intertidal zone.

Inside Passage water route in northwest North America

The Inside Passage is a coastal route for ships and boats along a network of passages which weave through the islands on the Pacific NW coast of North America. The route extends from southeastern Alaska, in the United States, through western British Columbia, in Canada, to northwestern Washington state, in the United States. Ships using the route can avoid some of the bad weather in the open ocean and may visit some of the many isolated communities along the route. The Inside Passage is heavily travelled by cruise ships, freighters, tugs with tows, fishing craft and ships of the Alaska Marine Highway, BC Ferries, and Washington State Ferries systems.

Columbia Bar

The Columbia Bar, also frequently called the Columbia River Bar, is a system of bars and shoals at the mouth of the Columbia River spanning the U.S. states of Oregon and Washington. The bar is about 3 miles (5 km) wide and 6 miles (10 km) long.

Humboldt Bay bay on the North Coast of California

Humboldt Bay is a natural bay and a multi-basin, bar-built coastal lagoon located on the rugged North Coast of California, entirely within Humboldt County. It is the largest protected body of water on the West Coast between San Francisco Bay and Puget Sound, the second largest enclosed bay in California, and the largest port between San Francisco and Coos Bay, Oregon. The largest city adjoining the bay is Eureka, the regional center and county seat of Humboldt County, followed by the town of Arcata. These primary cities together with adjoining unincorporated communities and several small towns comprise a Humboldt Bay Area total population of nearly 80,000 people, which accounts for nearly 60% of the population of Humboldt County. In addition to being home to more than 100 plant species, 300 invertebrate species, 100 fish species, and 200 bird species, the bay and its complex system of marshes and grasses support hundreds of thousands of migrating and local shore birds. Commercially, this second largest estuary in California houses the largest oyster production operations on the West Coast, producing more than half of all oysters farmed in California.

Intertidal zone The area of coast between low and high tide marks

The intertidal zone, also known as the foreshore and seashore and sometimes referred to as the littoral zone, is the area that is above water at low tide and underwater at high tide. This area can include many different types of habitats, with many types of animals, such as starfish, sea urchins, and numerous species of coral.

Rocky shore An intertidal area of coast where solid rock predominates

A rocky shore is an intertidal area of seacoasts where solid rock predominates. Rocky shores are biologically rich environments, and are a useful "natural laboratory" for studying intertidal ecology and other biological processes. Due to their high accessibility, they have been well studied for a long time and their species are well known.

Salt Point State Park

Salt Point State Park is a state park in Sonoma County, California, United States. The park covers 6,000 acres (2,400 ha) on the coast of Northern California, with 20 miles (32 km) of hiking trails and over 6 miles (9.7 km) of a rough rocky coast line including Salt Point which protrudes into the Pacific Ocean. The park also features the first underwater preserves in California. The constant impact of the waves forms the rocks into many different shapes. These rocks continue underwater providing a wide variety of habitats for marine organisms. The activities at Salt Point include hiking, camping, fishing, scuba diving and many others. The weather is cool with fog and cold winds even during the summer.

The shoreline is where the land meets the sea and it is continually changing. Over the long term, the water is eroding the land. Beaches represent a special case, in that they exist where sand accumulated from the same processes that strip away rocky and sedimentary material. That is, they can grow as well as erode. River deltas are another exception, in that silt that erodes up river can accrete at the river's outlet and extend ocean shorelines. Catastrophic events such as tsunamis, hurricanes and storm surges accelerate beach erosion, potentially carrying away the entire sand load. Human activities can be as catastrophic as hurricanes, albeit usually over a longer time interval.

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

Natural Bridges State Marine Reserve

Natural Bridges State Marine Reserve (SMR) is a marine protected area located at the northern edge of Santa Cruz, California, approximately 75 miles (121 km) south of San Francisco. The SMR covers 0.58 square miles (1.5 km2). The SMR protects all marine life within its boundaries. Fishing or other removal of any living marine resource is prohibited.

Duxbury Reef State Marine Conservation Area

Duxbury Reef State Marine Conservation Area (SMCA) is a marine protected area located about 1 mile (2 km) west of Bolinas in Marin County on California’s north central coast. This marine protected area covers 0.66 square miles (1.7 km2). Duxbury Reef SMCA prohibits the take of all living marine resources, except the recreational take of finfish from shore only and the recreational take of abalone.

Marine habitats A habitat that supports marine life

The marine environment supplies many kinds of habitats that support marine life. Marine life depends in some way on the saltwater that is in the sea. A habitat is an ecological or environmental area inhabited by one or more living species.

<i>Fucus distichus</i> species of alga

Fucus distichus or rockweed is a species of brown alga in the family Fucaceae to be found in the intertidal zones of rocky seashores in the Northern Hemisphere, mostly in rock pools.

Crystal Cove State Marine Conservation Area (SMCA) is one of a cluster of four adjoining marine protected areas that extend offshore of Newport Beach in Orange County on California’s south coast. The SMCA covers 3.45 square miles of near shore waters. Crystal Cove protects marine life by limiting the removal of marine wildlife from within its borders, including tide pools. Take of all living marine resources is prohibited except: recreational take of finfish by hook-and-line or by spearfishing, and lobster and sea urchin is allowed. Commercial take of coastal pelagic species by round haul net, spiny lobster by trap, and sea urchin is allowed.

References

  1. Spellman, Frank R. (2010-03-16). Geography for Nongeographers. Government Institutes. p. 30. ISBN   9781605906874.
  2. 1 2 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.