Matches in DBpedia 2016-04 for { ?s ?p "Barrier islands are coastal landforms and a type of dune system that are exceptionally flat or lumpy areas of sand that form by wave and tidal action parallel to the mainland coast. They usually occur in chains, consisting of anything from a few islands to more than a dozen. They are subject to change during storms and other action, but absorb energy and protect the coastlines and create areas of protected waters where wetlands may flourish. A barrier chain may extend uninterrupted for over a hundred kilometers, excepting the tidal inlets that separate the islands, the longest and widest being Padre Island of Texas. The length and width of barriers and overall morphology of barrier coasts are related to parameters including tidal range, wave energy, sediment supply, sea-level trends, and basement controls.Chains of barrier islands can be found along approximately thirteen percent of the world's coastlines. They display different settings, suggesting that they can form and be maintained in a variety of environmental settings. Numerous theories have been given to explain their formation.Lower shorefaceThe shoreface is the part of the barrier where the ocean meets the shore of the island. The barrier island body itself separates the shoreface from the backshore and lagoon/tidal flat area. Characteristics common to the lower shoreface are fine sands with mud and possibly silt. Further out into the ocean the sediment becomes finer. The effect from the waves at this point is weak because of the depth. Bioturbation is common and many fossils can be found here.Middle shorefaceThe middle shore face is located in the upper shoreface. The middle shoreface is strongly influenced by wave action because of its depth. Closer to shore the grain size will be medium size sands with shell pieces common. Since wave action is heavier, bioturbation is not likely.Upper shorefaceThe upper shore face is constantly effected by wave action. This results in development of herringbone sedimentary structures because of the constant differing flow of waves. Grain size is larger sands.ForeshoreThe foreshore is the area on land between high and low tide. Like the upper shoreface, it is constantly affected by wave action. Cross bedding and lamination are present and coarser sands are present because of the high energy present by the crashing of the waves. The sand is also very well sorted.BackshoreThe backshore is always above the highest water level point. The berm is also found here which marks the boundary between the foreshore and backshore. Wind is the important factor here, not water. During strong storms high waves and wind can deliver and erode sediment from the backshore.DunesThe dunes are located at the top of the backshore. The dunes are typical of a barrier island. The high sand dunes are only affected by wind because of their height. Similarly, strong storms are the only thing that really affect the size of the dunes. The dunes will display characteristics of typical eolian wind blown dunes. The difference here is that dunes on a barrier island typically contain vegetation roots and marine bioturbation.Lagoon and tidal flatsThe lagoon and tidal flat area is located behind the dune and backshore area. Here the water is still and this allows for fine silts, sands, and mud to settle out. Lagoons can become host to an anaerobic environment. This will allow high amounts of organic rich mud to form. Vegetation is also common."@en }
Showing triples 1 to 2 of
2
with 100 triples per page.
- Barrier_island abstract "Barrier islands are coastal landforms and a type of dune system that are exceptionally flat or lumpy areas of sand that form by wave and tidal action parallel to the mainland coast. They usually occur in chains, consisting of anything from a few islands to more than a dozen. They are subject to change during storms and other action, but absorb energy and protect the coastlines and create areas of protected waters where wetlands may flourish. A barrier chain may extend uninterrupted for over a hundred kilometers, excepting the tidal inlets that separate the islands, the longest and widest being Padre Island of Texas. The length and width of barriers and overall morphology of barrier coasts are related to parameters including tidal range, wave energy, sediment supply, sea-level trends, and basement controls.Chains of barrier islands can be found along approximately thirteen percent of the world's coastlines. They display different settings, suggesting that they can form and be maintained in a variety of environmental settings. Numerous theories have been given to explain their formation.Lower shorefaceThe shoreface is the part of the barrier where the ocean meets the shore of the island. The barrier island body itself separates the shoreface from the backshore and lagoon/tidal flat area. Characteristics common to the lower shoreface are fine sands with mud and possibly silt. Further out into the ocean the sediment becomes finer. The effect from the waves at this point is weak because of the depth. Bioturbation is common and many fossils can be found here.Middle shorefaceThe middle shore face is located in the upper shoreface. The middle shoreface is strongly influenced by wave action because of its depth. Closer to shore the grain size will be medium size sands with shell pieces common. Since wave action is heavier, bioturbation is not likely.Upper shorefaceThe upper shore face is constantly effected by wave action. This results in development of herringbone sedimentary structures because of the constant differing flow of waves. Grain size is larger sands.ForeshoreThe foreshore is the area on land between high and low tide. Like the upper shoreface, it is constantly affected by wave action. Cross bedding and lamination are present and coarser sands are present because of the high energy present by the crashing of the waves. The sand is also very well sorted.BackshoreThe backshore is always above the highest water level point. The berm is also found here which marks the boundary between the foreshore and backshore. Wind is the important factor here, not water. During strong storms high waves and wind can deliver and erode sediment from the backshore.DunesThe dunes are located at the top of the backshore. The dunes are typical of a barrier island. The high sand dunes are only affected by wind because of their height. Similarly, strong storms are the only thing that really affect the size of the dunes. The dunes will display characteristics of typical eolian wind blown dunes. The difference here is that dunes on a barrier island typically contain vegetation roots and marine bioturbation.Lagoon and tidal flatsThe lagoon and tidal flat area is located behind the dune and backshore area. Here the water is still and this allows for fine silts, sands, and mud to settle out. Lagoons can become host to an anaerobic environment. This will allow high amounts of organic rich mud to form. Vegetation is also common.".
- Q1205140 abstract "Barrier islands are coastal landforms and a type of dune system that are exceptionally flat or lumpy areas of sand that form by wave and tidal action parallel to the mainland coast. They usually occur in chains, consisting of anything from a few islands to more than a dozen. They are subject to change during storms and other action, but absorb energy and protect the coastlines and create areas of protected waters where wetlands may flourish. A barrier chain may extend uninterrupted for over a hundred kilometers, excepting the tidal inlets that separate the islands, the longest and widest being Padre Island of Texas. The length and width of barriers and overall morphology of barrier coasts are related to parameters including tidal range, wave energy, sediment supply, sea-level trends, and basement controls.Chains of barrier islands can be found along approximately thirteen percent of the world's coastlines. They display different settings, suggesting that they can form and be maintained in a variety of environmental settings. Numerous theories have been given to explain their formation.Lower shorefaceThe shoreface is the part of the barrier where the ocean meets the shore of the island. The barrier island body itself separates the shoreface from the backshore and lagoon/tidal flat area. Characteristics common to the lower shoreface are fine sands with mud and possibly silt. Further out into the ocean the sediment becomes finer. The effect from the waves at this point is weak because of the depth. Bioturbation is common and many fossils can be found here.Middle shorefaceThe middle shore face is located in the upper shoreface. The middle shoreface is strongly influenced by wave action because of its depth. Closer to shore the grain size will be medium size sands with shell pieces common. Since wave action is heavier, bioturbation is not likely.Upper shorefaceThe upper shore face is constantly effected by wave action. This results in development of herringbone sedimentary structures because of the constant differing flow of waves. Grain size is larger sands.ForeshoreThe foreshore is the area on land between high and low tide. Like the upper shoreface, it is constantly affected by wave action. Cross bedding and lamination are present and coarser sands are present because of the high energy present by the crashing of the waves. The sand is also very well sorted.BackshoreThe backshore is always above the highest water level point. The berm is also found here which marks the boundary between the foreshore and backshore. Wind is the important factor here, not water. During strong storms high waves and wind can deliver and erode sediment from the backshore.DunesThe dunes are located at the top of the backshore. The dunes are typical of a barrier island. The high sand dunes are only affected by wind because of their height. Similarly, strong storms are the only thing that really affect the size of the dunes. The dunes will display characteristics of typical eolian wind blown dunes. The difference here is that dunes on a barrier island typically contain vegetation roots and marine bioturbation.Lagoon and tidal flatsThe lagoon and tidal flat area is located behind the dune and backshore area. Here the water is still and this allows for fine silts, sands, and mud to settle out. Lagoons can become host to an anaerobic environment. This will allow high amounts of organic rich mud to form. Vegetation is also common.".