Near shore waves

The near shore waves critical for the design of the plant should be identified by comparing the histories of various heights of incident deep water, transition water and shallow water waves and hmiting breaking waves, with account taken 

Available historical data on observed extreme waves for the region should be reviewed to verify the results of the analysis of near shore waves. 

For each structure, system or component important to safety that is potentially exposed to coastal water action, the characteristics of the design wave should be evaluated from the selected near shore waves, with account taken of the propagation of these waves to the base of the structure. This evaluation consists of  

In calculating the maximum wave periods a value of 1.2 times the significant wave period is normally used for deep water for calculation of the minimum wave period, the limitation of wave steepness in shallow water is appropriate. The significant wave period may be taken to be approximately the same as the average wave period. The peak period of the waves in shallow water can be up to twice the mean period. 

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In the North Sea the pipeline surroundings will be at sea bottom temperature, so we are Interested in minimum temperatures at that location. Surprisingly, in the deeper water (250 ) of the northern North Sea areas which are affected by the Gulf Stream, the minimum sea bottom temperatures may be as high as 46 to 48°F. In southern North Sea areas which are less affected by the Gulf Stream and also may be shallower, with bottom temperatures more influenced by wave action, we can expect minimums of 40°F or less. Only in very shallow waters near shore can we expect minimum temperatures approaching 32 F. 

Surges represent a serious hazard for the low coasts of the Kerch Strait. For example, during the hurricane of 28-29 October 1969, a surge wave fully flooded a coastal band a few kilometers wide. The surge height exceeded 3 m. The flood was accompanied by the destruction of near-shore constructions and communications and human losses. 

The Crimean shelf extends from Cape Khersones in the west to Cape Meganom in the east. It is widest off Cape Sarych (35-40 km) and narrowest off Cape Ayu Dag (5 km) [1,2]. This region is subjected to intensive wave action because it is exposed to all the southerly winds. The boundary of the underwater coastal slope is located at depths of 30-40 m. The near-shore zone is the area of alongshore sediment transport and smoothing of the bottom topography. Underwater and dried abrasive remnants are common the largest of them are confined to the capes composed of strong volcanic rocks [7,8]. 

Wave action, currents, and gravity processes define the particular features of the redistribution of the bottom sediments, their zonation, and the existence of coarse-grained matter in the near-shore zone subjected to wave action, and of the fine-grained fraction beyond this zone at greater depths. Unusual features in the bottom sediment distribution may be caused by the activity of turbidity flows and landslide processes, which distort the general regularities of the lithological zonation. 

The Crimean region is characterized by alongshore variations in the sediments of the underwater slope. West of the Tarkhankut Peninsula up to Evpatoriya, biogenic coquina deposits dominate they cover the limestone bedrock. On the Crimean shelf, terrigenous sediments are also observed represented by boulders and pebbles in the near-shore zone, sands at depths down to 7-10 m, and fine sands and silty oozes at greater depths. Meanwhile, at depths of about 30 m, there exists a sandy-pebbly bar formed by extreme waves. 

One can find one more manifestation of the intra-annual evolution of the fields shown in Fig. 8 in the displacement and changes in the intensities of the local salinity extremes—the central maximums and the near-shore min-imums. The most distinct change is the westward displacement of the central salinity maximums occurring from February to May (see Fig. 8a,b) with the formation of a common maximum centered at 32° E in August (see Fig. 8c). The August salinity field at the 100-m level is characterized by an alternation of minimums and maximums from the east to the west with a wavelength of 350-400 km, well known as Knipovich s spectacles [2-4], With respect to their sizes, directions, and phase shift rates, they correspond to mid-latitude baroclinic Rossby waves [22,23]. 

The measurements were to provide information on sand displacements over the sea floor and sand suspension in the water column by currents and waves in near-shore waters. The sand transports cause an undesired sand filling of the shallow local shipping line from and to Stralsund in the local Gellenstrom area off Hiddensee. The question was where is the sand... 

Seagrass beds are composed of rooted, seed-bearing marine plants (halaphytes). They occur in shallow, near-shore waters, which are sheltered from high wave energy, and... 

A tsunami is a train of water waves generated by impulsive disturbances of the water surface due to non-meteorological but geophysical phenomena such as submarine earthquakes, volcanic eruptions, submarine slumps and landslides or ice falls into a body of water. The severity of the waves at the nuclear power plant will depend on the characteristics of the seabed movement, the location of the plant (whether it is near a fjord or bay) and the direction of movement with respect to the plant, and the response of the near shore waters to the tsunami waves. Depending on its location, the site might be subjected to damaging waves. 

This allows to locate the source areas and track their movement by means of seismic arrays (e.g., Cessaro, 1994 Friedrich et al. 1998, Fig. 5). This possibihty has already been used decades ago by some countries, e.g., in India, for tracking approaching monsoons with seismic networks under the auspices of the Indian Meteorological Survey. While near-shore areas may be the source of both primary and secondary microseisms, the pelagic sources of secondary microseisms meander within the synoptic region of peak storm wave activity. 

At the upper end of the VLP band from about 8 to 3 s period, the ubiquitous oceanic microseis-mic signal typically dominates. This signal, which is primarily due to interactions between ocean waves and the near-shore ocean floor, is observed everywhere on Earth but is particularly strong at ocean islands. Therefore the upper end of the observable VLP band is, in most cases, about 8 s. 

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