scholarly journals BEACH PROFILES AT TORREY PINES, CALIFORNIA

1976 ◽  
Vol 1 (15) ◽  
pp. 75 ◽  
Author(s):  
David G. Aubrey ◽  
Douglas L. Inman ◽  
Charles E. Nordstrom
Keyword(s):  
Sediment Transport ◽  
Incident Wave ◽  
Wave Energy ◽  
Energy Conditions ◽  
Beach Profile ◽  
High Wave ◽  
Wave Characteristics ◽  
Spectral Estimates ◽  
High Wave Energy ◽  
Incident Waves

Beach profiles have been measured at Torrey Pines Beach, California for four years and correlated with tides and accurate spectral estimates of the incident wave field. Characteristic equilibrium beach profiles persist for time spans of up to at least two weeks in response to periods of uniform incident waves. These changes in the beach profiles are primarily due to on-offshore sediment transport which can be related to variations in wave characteristics and tidal phase. The most rapid readjustment of the beach profile occurs during high wave energy conditions coincident with spring tides. Alternatively, the highest berm building is associated with moderate to low waves that coincide with spring tides.

scholarly journals Estimation of Longshore Sediment Transport Using Video Monitoring Shoreline Data

2020 ◽  
Vol 8 (8) ◽  
pp. 572
Author(s):  
Jung-Eun Oh ◽  
Yeon S. Chang ◽  
Weon Mu Jeong ◽  
Ki Hyun Kim ◽  
Kyong Ho Ryu
Keyword(s):  
Sediment Transport ◽  
Recovery Process ◽  
Video Monitoring ◽  
Energy Conditions ◽  
Winter Storms ◽  
Shoreline Changes ◽  
Longshore Sediment Transport ◽  
Beach Processes ◽  
Line Theory ◽  
Incident Waves

Video monitoring systems (VMS) have been used for beach status observation but are not effective for examining detailed beach processes as they only measure changes to the shoreline and backshore. Here, we extracted longshore sediment transport (LST) from VMS in order to investigate long- and short-term littoral processes on a pocket beach. LST estimated by applying one-line theory, wave power, and the oblique angle of incident waves were used to understand shoreline changes caused by severe winter storms. The estimated LST showed good agreement with the shoreline changes because the sediments were trapped at one end of the pocket beach and the alongshore direction of transported sediments was corresponded to the direction of LST. The results also showed that the beach that was severely eroded during storms was also rapidly recovered following the evolution of LST, which indicates that the LST may play a role in the recovery process while the erosion was mainly caused by the cross-shore transport due to storm waves. After the beach was nourished, beach changes became more active, even under lower wave energy conditions, owing to the equilibrium process. The analysis presented in this study could be applied to study inhomogeneous beach processes at other sites.

SHORELINE OIL TWO YEARS AFTER AMOCO CADIZ: NEW COMPLICATIONS FROM TANIO

1981 ◽  
Vol 1981 (1) ◽  
pp. 525-534 ◽  
Author(s):  
Erich R. Gundlach ◽  
Serge Berné ◽  
Laurent D'Ozouville ◽  
Jerry A. Topinka
Keyword(s):  
Oil Spill ◽  
Wave Energy ◽  
Heavy Oil ◽  
Interstitial Water ◽  
Tidal Flats ◽  
Rocky Shores ◽  
High Wave ◽  
Spill Site ◽  
High Wave Energy

ABSTRACT The latest in a series of joint Franco-American surveys of the Amoco Cadiz (233,000 tons; March 17, 1978) spill site was conducted during May and June 1980. The purposes of this survey were to determine remaining surface oil, buried oiled sediment, oil incorporation in interstitial water, and recovery of attached macroalgae. Oil was found to persist primarily as tar blotches and black staining along exposed rocky shores and as oil-contaminated (indicated by surface sheen), interstitial water in previously heavily oiled, sheltered tidal flats. Less commonly, oil was present as asphalted sediment and oil-coated rocks in sheltered embayments. The cleaned marsh at Ile Grande remained significantly damaged from the oil; however, both upper and lower marsh grasses showed some recovery. At another marsh, no recovery occurred in uncleaned, heavily oiled areas. On sheltered rocky shores, heavily oiled algae showed rapid recolonization by Fucus; however, Ascophyllum noaosum-dominated areas showed less recovery. The Tanio oil spill on March 7, 1980 (7,000 tons lost) impacted 45 percent of the Amoco Cadiz spill site and severely complicated further differentiation of Amoco Cadiz oil in many areas. In total, 197 kilometers (km) of shoreline were impacted; 45 km were heavily oiled. Nine weeks after initial impact, Tanio oil occurred as patches of heavy oil along sheltered and exposed, rocky shores. Sand beaches and tidal flats were generally free of oil. Several hundred soldiers continued to pressure spray dispersants and water to clean up oiled areas, even in high wave energy and isolated localities.

Do longshore bars shelter the shore?

2000 ◽  
Vol 404 ◽  
pp. 251-268 ◽  
Author(s):  
JIE YU ◽  
CHIANG C. MEI
Keyword(s):  
Spatial Distribution ◽  
Incident Wave ◽  
Wave Energy ◽  
Phase Relation ◽  
Bragg Reflection ◽  
Qualitative Change ◽  
Numerical Calculations ◽  
Reflected Waves ◽  
Incident Waves ◽  
Incident Wave Energy

In most past theories on Bragg reflection of waves by a finite patch of rigid bars, only outgoing waves are allowed on the transmission side, simulating the effect of an idealized shoreline where all the incident wave energy is consumed by breaking. In these theories the amplitudes of both the incident and reflected waves are found to decrease monotonically over the bar patch in the shoreward direction. This result has motivated the idea of artificially constructing bars to protect a beach from incident waves. However, some numerical calculations have suggested that this tendency does not always hold when there is some reflection from the shore. We show here that with finite reflection by the shoreline the spatial distribution of wave energy over the patch can indeed be reversed, indicating that the mechanism can increase the hazards to the beach. The phase relation between the bars and the shoreline reflection is found to be the key to this qualitative change of wave response.

scholarly journals FIELD INVESTIGATION OF BEACH PROFILE CHANGES AND THE ANALYSIS USING EMPIRICAL EIGENFUNCTIONS

1982 ◽  
Vol 1 (18) ◽  
pp. 84
Author(s):  
Hiroshi Hashimoto ◽  
Takaaki Uda
Keyword(s):  
Sediment Transport ◽  
Time Lag ◽  
Field Investigation ◽  
Sand Transport ◽  
Wave Direction ◽  
Beach Profile ◽  
Sand Waves ◽  
Longshore Sediment Transport ◽  
Profile Changes ◽  
Incident Waves

In order to investigate the response of beach profiles to incident waves, computations by the empirical eigenfunction analysis proposed by Winant et al. are performed. The analysis of the data obtained at Ajigaura Beach over three years from 1976 to 1979 indicates that beach profile changes due to longshore and onshore-offshore sediment transport are separable by the empirical eigenfunction method. The beach profile changes due to longshore sediment transport has a time lag of 12 weeks with respect to the change of wave direction at Ajigaura Beach. It was found theoretically that this time lag was due to the sand waves propagating in the longshore direction. Regarding as onshore-offshore sand transport, the second eigenfunction is associated with the beach changes due to onshore-offshore sand transport caused by the change of wave height.

scholarly journals EFFECTS OF A VERTICAL SEAWALL ON PROFILE RESPONSE

1988 ◽  
Vol 1 (21) ◽  
pp. 111 ◽  
Author(s):  
Michael R. Barnett ◽  
Hsiang Wang
Keyword(s):  
Time Series ◽  
Sediment Transport ◽  
Incident Wave ◽  
Break Point ◽  
Two Dimensional ◽  
Limited Extent ◽  
Beach Profile ◽  
Temporal Profile ◽  
Recovery Response ◽  
Transport Patterns

An attempt is made to determine beach profile response due to the presence of a vertical seawall placed in various cross-shore positions, and to examine the differences between natural beaches and seawall-backed beaches in response to normally incident wave attack. The investigation was mainly restricted to two-dimensional profile response under erosive wave conditions, with beach recovery response monitored to a limited extent. Spatial and temporal profile response was investigated by examining time-series profile configuration, volumetric changes, sediment transport patterns, and quasiequilibrium profile configuration. Additionally, dominant profile features such as the break point and reflection bars (as well as scour at the toe of the seawall-backed profiles) were observed and quantified.

scholarly journals Microplastic pollution on island beaches, Oahu, Hawai`i

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247224
Author(s):  
Savannah Franklin Rey ◽  
Janet Franklin ◽  
Sergio J. Rey
Keyword(s):  
Wave Energy ◽  
Empirical Data ◽  
Hawaiian Islands ◽  
High Tide ◽  
Storm Tide ◽  
High Wave ◽  
Remote Island ◽  
High Wave Energy ◽  
Very High

We report microplastic densities on windward beaches of Oahu, Hawai`i, USA, an island that received about 6 million tourist visits a year. Microplastic densities, surveyed on six Oahu beaches, were highest on the beaches with the coarsest sands, associated with high wave energy. On those beaches, densities were very high (700–1700 particles m-2), as high as those recorded on other remote island beaches worldwide. Densities were higher at storm tide lines than high tide lines. Results from our study provide empirical data on the distribution of microplastics on the most populated and visited of the Hawaiian islands.

Abundance, composition and succession of sessile subtidal assemblages in high wave-energy environments of Central Chile: Temporal and depth variation

2019 ◽  
Vol 512 ◽  
pp. 51-62
Author(s):  
Sergio A. Navarrete ◽  
Mirtala Parragué ◽  
Nicole Osiadacz ◽  
Francisca Rojas ◽  
Jessica Bonicelli ◽  
...  
Keyword(s):  
Wave Energy ◽  
Central Chile ◽  
High Wave ◽  
Depth Variation ◽  
High Wave Energy
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