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Volume 35, Issue 5. Previous Article Next Article. Article Navigation. Research Article June 12 McFall Brian C. Coastal and Hydraulics Laboratory U.
Corresponding author: Brian. McFall usace. This Site. Google Scholar. The dye highlights the rip feeder current flowing along the base of the beach face, then turning to flow seaward in the deeper rip channel. When the broken wave reaches the base of the wet beach it collapses and runs up the beach face as swash or uprush in the swash zone Figure The uprush stops toward the top of the slope, some percolates into the beach, the remainder flows back down the beach as backwash.
As sediment is deposited in the swash zone it can build a berm , a near horizontal to slightly landward-dipping sand surface, the area where most people sit when they go to the beach. The swash zone may also contain beach cusps , spaced about every 20 to 30 m and produced by another form of edge wave Figure Figure 10 Wave runup on the steep beach face at Ke lli Beach, Hawaii. Figure 11 A steep reflective beach with well developed high tide beach cusps at Hammer Head, Western Australia.
Wave-dominated beaches have an RTR tide range less than three times the average wave height RTR Reflective beaches are produced by lower waves H Figure 12 A plot of breaker wave height versus sand size, together with wave period, that can be used to determine the approximate beach state for wave-dominated beaches. To use the chart, determine the breaker wave height, period and grain size mm. They are characterized by a surf zone with one or two bars up to m wide. The bar is usually cut by regular rip channels and currents Figure Figure 13 Well-developed intermediate beach containing transverse bars and rip channels along Lighthouse Beach, Australia.
Note the waves breaking on the bars, with no waves breaking in the deeper darker rip channels. Also note the rhythmic shoreline protruding in lee of the bars and forming an embayment in lee of the rips. Waves break on the outer then inner bar s , thereby dissipating their energy as the move across the surf zone Figure The swell breaks over the wide outer bar, reforms in the central trough, then breaks across the inner bar, resulting up to 10 lines of breakers and a m wide dissipative beach and surf zone.
They usually have a steep, coarser-grained, cusped, reflective, high tide beach. This is fronted by a wide, finer-grained, low gradient, often featureless, intertidal zone, up to m wide, then a low tide surf zone which may contain bars and rip channels Figure Figure 15 A steep reflective high tide beach face fronted by a m wide tide-modified low tide terrace crossed by shallow drainage channels at North Harbour Beach, Australia.
An additional beach type consists of a high tide reflective beach face fronted by intertidal rocks flats, and in the tropics a high tide beach fronted by a fringing coral reef flat Figure Furthermore any beach located in the high latitudes will be seasonally exposed to freezing air and water temperatures leading to the development of sea ice, shoreface ice, and a frozen snow covered beach Figure Figure 18 The beach at Pingok Island, north Alaska, shown a during summer, with floating ice against the shore; b during freeze-up, with snow and sea ice accumulating; and c the frozen winter beach and ocean.
Beach systems are an essential component of a larger scale coastal landform called barriers , which are long-term accumulation of wave, tide, and wind deposited marine sediment usually sand at the shore. When separated from the mainland by lagoons and marshes Figure 19 they are called barrier islands Figure 20 , which occur along the US East and Gulf coasts. Some are backed by large dune systems as along the Oregon coast. Figure 19 A coastal sand barrier consisting of a beach and vegetated dunes, backed by a lagoon, at Big Beach, Queensland, Australia.
Figure 20 A series of low barrier islands separated by tidal inlets, at Corner Inlet, Victoria, Australia. Davis, R. Davis, Jr. Komar, P. Beach Processes and Sedimentation , 2nd ed. Masselink, G. Introduction to Coastal Processes and Geomorphology.
Short, A. Handbook of Beach and Shoreface Morphodynamics. Australian beach systems — Nature and distribution. Journal of Coastal Research 22 , 11—27 The Coast of Australia. Melbourne, Australia: Cambridge University Press, Woodroffe, C. Coasts — Form and processes. Global Change: An Overview. Conservation of Biodiversity.
Introduction to the Basic Drivers of Climate. Tropical Weather. Terrestrial Biomes. Causes and Consequences of Dispersal in Plants and Animals. Causes and Consequences of Biodiversity Declines.
Disease Ecology. Coastal Dunes: Geomorphology. Coastal Processes and Beaches. Drip Water Hydrology and Speleothems. Earth's Earliest Climate. El Nino's Grip on Climate. Large-Scale Ecology Introduction.
Methane Hydrates and Contemporary Climate Change. Modeling Sea Level Rise. Ocean Acidification. Rivers and Streams - Water and Sediment in Motion.
Principles of Landscape Ecology. Spatial Ecology and Conservation. Restoration Ecology. Energy Economics in Ecosystems. Earth's Ferrous Wheel. The Ecology of Fire. Citation: Short, A. Nature Education Knowledge 3 10 Waves, tide, and wind dominate coastal processes and landforms. Rivers deliver sediment to the coast, where it can be reworked to form deltas, beaches, dunes, and barrier islands.
Aa Aa Aa. Coastal Processes. The coastal zone is that part of the land surface influenced by marine processes. A method for calculating spatially and temporally averaged beach slopes is presented here along with a method for determining total uncertainty for each m alongshore section of coastline.
A method for determining average beach slope and beach slope variability for U. By: Kara S.
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