Regularly-spaced grooves on shore platforms in north Northumberland, UK

2020 ◽  
Vol 63 (2) ◽  
pp. 124-134
Author(s):  
Alison M. Tymon ◽  
Barry G. Tymon
Keyword(s):  
Incident Wave ◽  
Wave Energy ◽  
Surf Zone ◽  
High Water ◽  
Edge Waves ◽  
Shore Platform ◽  
Bedding Planes ◽  
High Water Mark ◽  
Incident Wave Energy ◽  
Shore Platforms

Unusual regularly-spaced grooves are found between low water mark (LWM) and high water mark (HWM) on several shore platforms in north Northumberland. References in the literature are sparse, so data were collected to establish the nature of the grooves and to elucidate the processes that might have formed them. Groove formation is confined to strata with widely spaced bedding planes on shore platforms dipping at no more than 5° towards the sea. The grooves are symmetrical, bifurcation is common and grooves on sandstones are deeper and more sinuous than those on limestones. Grooves at mid-tide levels are wider than grooves near LWM and HWM and the trend of the grooves is not related to joint trends. The process that has formed the characteristically smooth surfaces of the grooves is considered to be abrasion by sand and pebbles carried by waves in the surf zone of the shore platform. The width of the grooves is remarkably regular, and it is suggested that this may be due to the effects of the increase in incident wave energy given by edge waves.

SHORELINE CLEANUP BY ACCELERATION OF CLAY-OIL FLOCCULATION PROCESSES

1997 ◽  
Vol 1997 (1) ◽  
pp. 235-240 ◽  
Author(s):  
Kenneth Lee ◽  
Tim Lunel ◽  
Peter Wood ◽  
Richard Swannell ◽  
Patricia Stoffyn-Egli
Keyword(s):  
Chemical Analysis ◽  
Oil Spill ◽  
Intertidal Zone ◽  
Surf Zone ◽  
High Water ◽  
Residual Oil ◽  
Oil Droplets ◽  
Oil Emulsion ◽  
Mineral Particles ◽  
High Water Mark

ABSTRACT During the cleanup operations following the Sea Empress oil spill, it was observed that the oil emulsion did not adhere strongly to the shoreline and that fine mineral particles present in the surf waters interacted with oil to form clay-oil floes. In an attempt to enhance clay-oil flocculation, Amroth beach was subjected to repeated “surf washing”: the oiled cobbles from the high water mark were moved down to the intertidal zone using an excavator at low tide. After 4 days of treatment, most of the oil emulsion was removed from the cobbles. We estimate that the majority of the oil was removed as clay-oil flocs and that the remainder was released from the cobbles as a broken surface slick. Microscopic and chemical analysis of samples of flocs and oiled sediments showed that energy imparted to the surf zone resulted in clay-oil flocculation, which increased biodegradation rates of the residual oil. Surf washing increased the availability of fine mineral particles, which (1) minimized the contact of oil directly with the substrate, thereby reducing the adhesion of oil to the shoreline, and (2) prevented the recoalescence of oil droplets, thereby promoting the dispersion of oil within the surf zone.

Evaluation of Incident Wave Energy in Flume Tests

1987 ◽  
Author(s):  
Eliezer Kit ◽  
Oded Gottlieb ◽  
Dov S. Rosen
Keyword(s):  
Incident Wave ◽  
Wave Energy ◽  
Flume Tests ◽  
Incident Wave Energy

scholarly journals FIELD EXPERIMENT ON BEACH GRAVEL TRANSPORT

1978 ◽  
Vol 1 (16) ◽  
pp. 101 ◽  
Author(s):  
Masataro Hattori ◽  
Takasuke Suzuki
Keyword(s):  
Field Experiment ◽  
Incident Wave ◽  
Wave Energy ◽  
Transport Processes ◽  
Central Japan ◽  
Selective Transport ◽  
Longshore Transport ◽  
Wave Energy Flux ◽  
The Mean ◽  
Incident Wave Energy

To examine the longshore transport processes of beach gravels under wave action, a field experiment was performed by tracing the dacite blocks injected on Fuji Coast, Shizuoka Prefecture, Central Japan. The mean dislocating velocity of the tracer was 2 to 3 m/day under normal sea conditions, while under storm conditions it reached about 400 m/day. This -velocity was fairly proportional to the longshore component of incident wave energy flux. The longshore variations of the size and shape of beach gravels were mainly resulted from the progressive attrition and impact breakage of beach gravels rather than from the selective transport.

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.

Shore platforms and wave ramps

1972 ◽  
Vol 109 (2) ◽  
pp. 81-88 ◽  
Author(s):  
E. Sherbon Hills
Keyword(s):  
Water Level ◽  
High Water ◽  
The Other ◽  
Shore Platform ◽  
Submarine Slope ◽  
High Water Level ◽  
Near Shore ◽  
Rocky Coasts ◽  
Shore Platforms

SummaryExamination of rocky coastal profiles in Australia and Europe suggests that two major and genetically distinct types of erosional surface should be recognized, one of these being the shore platform, whether sloping or horizontal, smooth or rough, which is best developed on promontories and terminates in a low-tide cliff, the other being the wave ramp, often exposed in bays, which slopes gradually down from about high water level to merge with the submarine slope near-shore. A modified terminology for erosional surfaces on rocky coasts is proposed.

scholarly journals RESEARCHES ON SEA-WALLS

1970 ◽  
Vol 1 (12) ◽  
pp. 88
Author(s):  
S. Nagal
Keyword(s):  
Incident Wave ◽  
Wave Energy ◽  
Precast Concrete ◽  
Recent Decade ◽  
Point Of View ◽  
Industrial Firms ◽  
Wave Overtopping ◽  
Port Facilities ◽  
Sea Wall ◽  
Incident Wave Energy

In the recent decade, very wide areas of sea where the depths of water are from several meters to ten meters or more during storms have been reclaimed for industrial firms and port facilities in many places in Japan As the incident wave energy in such cases is very large at the sea-walls, the protection of the reclaimed lands from wave overtopping by the conventional sea-walls of vertical type or composite-slope«and-berai type is generally impossible from an economical point of view In Japan a special type of sea-wall, which is of such a type that a rubble-mound covered with specially shaped precast concrete armor blocks is built in front of the sea-wall to absorb most of the incident wave energy, has been constructed to protect the reclaimed lands from wave overtopping Most of the seawalls have been proved satisfactory after passing of typhoons over or near the sea-walls The design of the sea-walls is presented here in by showing the comparisons between the experiments and prototypes during typhoons.

Model Experiment on an OWC-Type Wave-Energy Converter With Hydraulic Power Take-Off

2002 ◽  
Author(s):  
Torkel Bjarte-Larsson ◽  
Per Magne Lillebekken ◽  
Jo̸rgen Hals ◽  
Johannes Falnes
Keyword(s):  
Incident Wave ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Laboratory Model ◽  
Energy Converter ◽  
Hydraulic Power ◽  
Optimum Load ◽  
Wave Channel ◽  
Period 2 ◽  
Incident Wave Energy

A wave-energy converter of the OWC type is described, in which the absorbed wave energy is converted to useful energy by means of a hydraulic power take-off. Means are provided to enable the float to be latched for phase control. The float is connected to a piston pump, which pumps water from the level of the water in the wave channel to a higher level, which is adjustable. By means of measurements from three wave gauges (two on the upstream side and one on the downstream side) the incident wave energy and the absorbed wave energy are derived. For a down-scaled laboratory model, resonance is obtained with an incident sinusoidal wave of period 1 s. With optimum load, the converted useful hydraulic energy is a fraction of 0.2 of the incident wave energy. The absorbed wave energy is then 0.6 units of the incident wave energy. With wave period 2 s and optimum load, these energy fractions are 0.03 and 0.13, which are increased to 0.05 and 0.21, respectively, when latching control is applied.

scholarly journals EVALUATION OF INCIDENT WAVE ENERGY IN FLUME TEST

1986 ◽  
Vol 1 (20) ◽  
pp. 93
Author(s):  
Eliezer Kit ◽  
Oded Gottlieb ◽  
Dov S. Rosen
Keyword(s):  
Least Squares ◽  
Incident Wave ◽  
Wave Energy ◽  
Least Squares Method ◽  
Stationary Wave ◽  
Residual Energy ◽  
Irregular Waves ◽  
Wave Spectra ◽  
Reflected Wave ◽  
Incident Wave Energy

A two dimensional model study, carried out for a structure in a flume using irregular waves, presents the problem of determining the relationship between the total incident wave energy attacking the structure and its response to that attack (displacements, forces, etc.) in various sea states, The total incident wave energy can be evaluated indirectly only, because the wave energy measured in the flume contains an extent of residual wave energy in addition to that generated by the wave machine. This residual energy consists of the re-reflected wave energy from the paddle of the wave machine, assuming the existence of quasi-stationary wave conditions in the flume. A method originally presented by Gravesen et al. (1974), was applied in this study to evaluate the total incident wave energy. In view of the results obtained by this method, a physically more sound refinement is proposed for the evaluation of the total incident wave energy (and characteristic wave height). Results of model tests were analyzed by the CAMERI refinement and compared with the Gravesen method and with a cross-spectral least squares method, separating incident and reflected wave spectra from wave spectra measured in the flume, Good agreement was found between the results obtained employing the CAMERI refinement and the cross-spectral least squares method, Advantages and drawbacks of these methods are indicated,

Alongshore variations in morphology and incident wave energy on a human-impacted coast: Agadir, Morocco.

2016 ◽  
Vol 75 (sp1) ◽  
pp. 1027-1031 ◽  
Author(s):  
Ismail Aouiche ◽  
Lahcen Daoudi ◽  
Edward J. Anthony ◽  
Mouncef Sedrati ◽  
Abdelhadi El Mimouni ◽  
...  
Keyword(s):  
Incident Wave ◽  
Wave Energy ◽  
Incident Wave Energy
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