Application of the Generic Spectral Formula to Fetch-Limited Seas

1999 ◽  
Vol 33 (3) ◽  
pp. 27-32 ◽  
Author(s):  
Michael E. McCormick
Keyword(s):  
Probability Distribution ◽  
Deep Water ◽  
Spectral Peak ◽  
Peak Enhancement ◽  
Spectral Formula

A deep-water spectral formula, based on the Weibull probability distribution of wave periods, is modified to satisfy fetch-limited conditions for wind-generated seas Results of this generic spectral formula are compared with those obtained using the specific JONSWAP formula, in which the empirical parameters resulting from specific wind and fetch conditions are used. The comparisons are shown to be excellent for three of the five cases studied. For the last two cases, the generic formula is shown to be somewhat nonconservative near the spectral peak. In addition to the comparisons with the specific JONSWAP formula results, the generic formula results are compared with those obtained from the standard JONSWAP expression, where the Pierson-Moskowitz parametric values and averaged peak-enhancement values are used. Except for the greatest fetch length (37 km), the standard JONSWAP formula is shown to significantly under-predict the peak spectra values. The generic spectral formula is found to well-predict the spectra for fetch lengths of 11 km and greater.

scholarly journals HURRICANE WAVE STATISTICS FOR THE GULF OF MEXICO

2011 ◽  
Vol 1 (6) ◽  
pp. 4
Author(s):  
Basil W. Wilson
Keyword(s):  
Probability Distribution ◽  
Gulf Of Mexico ◽  
Deep Water ◽  
Tropical Storms ◽  
Arrival Times ◽  
Wave Statistics ◽  
Normal Probability ◽  
Wave Heights ◽  
Normal Probability Distribution

This paper contains the results of a statistical hindcast study of the heights and periods of significant waves generated by hurricanes in the Gulf of Mexico in the period 1900 to 1949. Results are presented in a series of polar plots of frequencies of occurrence of waves of given height and period at deep-water (100 fathoms depth) stations at different bearings offshore from five coastal stations (Brownsville, Tex., Gilchrist, Tex., Burrwood, Miss., Apalachicola, Fla., Tampa, Fla.). Analysis was conducted by selecting a sample of 9 hurricanes and hindcasting by graphical moving fetch techniques, wave heights, periods and arrival times along eleven approach-directions to the five coastal stations for one storm, and from two to three approach directions for the remaining eight storms. Maximum heights and periods were correlated with hurricane characteristics (pressure, radius of maximum winds, forward velocity and direction). From the correlation the sample was increased by an additional 23 hurricanes whose characteristics were known. Heights and periods plotted against frequencies of occurrence gave mainly normal probability distribution Finally taking account of the total number of tropical storms occurring in the Gulf of Mexico in 50 years and the incidences of waves from various direction at the five stations, the chances of occurrence of full hurricane waves were evaluated.

scholarly journals LENGTHS OF RUNS OF JUST BREAKING AND BROKEN WAVES IN IRREGULAR WAVE TRAIN ON GENTLE SLOPES

1986 ◽  
Vol 1 (20) ◽  
pp. 89
Author(s):  
Koichiro Iwata ◽  
Shunji Itoh
Keyword(s):  
Theoretical Model ◽  
Probability Distribution ◽  
Deep Water ◽  
Wave Train ◽  
Mean Values ◽  
Run Length ◽  
Irregular Wave

This paper is aimed to investigate theoretically and experimentally the variations of the probability distribution and mean values of the run length and total run length of just breaking and broken waves in an irregular wave train on gentle slopes. The theoretical model developed here is shown to be valid for evaluating the lengths of runs of just and broken waves from deep water up to the shoreline.

Benthic foraminiferal zonation in deep-water carbonate platform margin environments, northern Little Bahama Bank

1988 ◽  
Vol 62 (01) ◽  
pp. 1-8 ◽  
Author(s):  
Ronald E. Martin
Keyword(s):  
Deep Water ◽  
Benthic Foraminifera ◽  
Carbonate Platform ◽  
Sedimentary Facies ◽  
Depositional Environments ◽  
Near Surface ◽  
Sediment Gravity Flows ◽  
Gravity Flows ◽  
Platform Margin ◽  
Water Carbonate

The utility of benthic foraminifera in bathymetric interpretation of clastic depositional environments is well established. In contrast, bathymetric distribution of benthic foraminifera in deep-water carbonate environments has been largely neglected. Approximately 260 species and morphotypes of benthic foraminifera were identified from 12 piston core tops and grab samples collected along two traverses 25 km apart across the northern windward margin of Little Bahama Bank at depths of 275-1,135 m. Certain species and operational taxonomic groups of benthic foraminifera correspond to major near-surface sedimentary facies of the windward margin of Little Bahama Bank and serve as reliable depth indicators. Globocassidulina subglobosa, Cibicides rugosus, and Cibicides wuellerstorfi are all reliable depth indicators, being most abundant at depths >1,000 m, and are found in lower slope periplatform aprons, which are primarily comprised of sediment gravity flows. Reef-dwelling peneroplids and soritids (suborder Miliolina) and rotaliines (suborder Rotaliina) are most abundant at depths <300 m, reflecting downslope bottom transport in proximity to bank-margin reefs. Small miliolines, rosalinids, and discorbids are abundant in periplatform ooze at depths <300 m and are winnowed from the carbonate platform. Increased variation in assemblage diversity below 900 m reflects mixing of shallow- and deep-water species by sediment gravity flows.

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