scholarly journals ZEEBRUGGE'S MAIN BREAKWATERS

1982 ◽  
Vol 1 (18) ◽  
pp. 105
Author(s):  
L.V. Van Damme
Keyword(s):  
Water Depth ◽  
Wave Breaking ◽  
Economic Benefit ◽  
Environmental Design ◽  
The West ◽  
Stability Performance ◽  
Final Design ◽  
Technical Risks ◽  
General Cargo ◽  
Concrete Cube

The design scheme of the Zeebrugge Outer Harbour, Belgium, consists mainly of two breakwaters protruding into the sea as far as 1,750 m beyond the existing mole or 3.000 m out from the coastline. The west outer breakwater is 4,450 m long, the east breakwater runs 4,300 m out from the seafront. The east outer harbour will accommodate terminals for liquid bulk products such as LNG. The west outer harbour will provide space to install two harbour bassins to suit general cargo, hazardous cargo, container and ferry traffic. In the paper emphasis is put on the environmental design conditions (wave height, wave period, water depth), the development of preliminary designs and the final design. Some design features such as dimensions, wave breaking carpet, armour units, workable limits in respect to rock grade, etc ... are discussed. By developing the design the rubble-mound breakwater has been judged to be the only viable alternative versus the caisson type breakwater, taking into account costs, technical risks, construction problems and flexibility under changing environmental conditions. The main feature of the breakwaters is that a huge concrete parapet will have been avoided. A so called flat semi-cube armour unit has been developed. The main advantage lies in the substantial economic benefit whilst maintaining the same stability performance as a concrete cube armour unit.

Wave-Island Interactions About Circular Artificial Islands

1984 ◽  
Vol 106 (1) ◽  
pp. 113-119 ◽  
Author(s):  
J. M. Niedzwecki
Keyword(s):  
Closed Form ◽  
Water Depth ◽  
Wave Breaking ◽  
Numerical Procedure ◽  
Wave Pattern ◽  
The Arctic ◽  
Ray Theory ◽  
Closed Form Solutions ◽  
Wave Patterns ◽  
Dimensionless Formulation

The behavior of waves interacting with islands has gained renewed interest with the construction of exploratory drilling islands in the Arctic. This paper focuses upon the behavior of waves incident upon axisymmetric islands characterized by circular contours which vary with water depth. The island profiles of Arthur and Pocinki, which have closed form solutions, and a single tier conical island are examined. A new dimensionless formulation of Arthur’s ray theory and an extremely accurate numerical procedure to evaluate the ray integrals are presented. It is shown that each island profile leads to a distinct wave pattern about the island. These wave patterns are presented in figures which portray the wave capture and wave breaking about circular islands. It is intended that the methodology presented be used to initially assess trends and to evaluate the need for more refined analyses.

Submarine landslides in the west continental slope of the South China Sea and their tsunamigenic potential

2021 ◽  
Author(s):  
Xiaoyi Pan ◽  
Linlin Li ◽  
Hong Phuong Nguyen ◽  
Dawei Wang
Keyword(s):  
South China Sea ◽  
Shear Zone ◽  
Continental Slope ◽  
South China ◽  
Water Depth ◽  
Red River ◽  
Submarine Landslides ◽  
The West ◽  
Tsunami Waves ◽  
Central Vietnam

<p>The 109 meridian fault is located in the west of the South China Sea (SCS) connecting to the offshore Red River Shear Zone. The evolution processes of the 109 meridian fault: striking-uplifting-subsidence of adjacent basin led to a nearly 1000m sharp bathymetric difference in the offshore region of central Vietnam. Combined with the high sediment input from numerous montane rivers in the rising hinterland, the continental slope near central Vietnam possesses the ideal condition for developing submarine landslides. Seismic data indicates many submarine landslides were developed along the steep continental slope. In this study, we analyze the possible trigger mechanisms of these landslides based on the local geological background and sedimentary environment, and assess their tsunamigenic potential along the coast of the Southern Central Vietnam (SCV). We point out that the landslide failures in this region could be triggered by several mechanisms, including seismic activities in the offshore SCV, volcanic activities, gas seep on the slope and the relative sea-level changes. The seismic and volcanic activities are related directly to the late middle Miocene volcanism generated by the change from left- to right-lateral motion on the Red River Shear Zone, showing that tectonism play a significant role in the generation of submarine landslide in the western continental slope of the SCS. To estimate the impact of tsunami waves on SCV coastline, we use two numerical models—NHWAVE and FUNWAVE-TVD to model 4 representative landslides with volume ranging between 1-4km<sup>3</sup> and water depth of 300-1000m. The submarine landslides were treated as rigid slump and deformable slide corresponding to two different sedimentary environments. Our results show that the tsunami waves generated by rigid slump can reach up to 20m height in the landslide source area and arrive earlier to the coast of SCV than waves generated by deformable slide. Among these simulated scenarios, tsunami waves generated by the worst-case scenario arrive at the populated cities including Quy Nhơn (109.3°E,13.77°N), Tuy Hòa (109.37°E ,13.08°N) and Vung Ro Bay (109.43°E，12.86°N) in less than 25mins with maximum height of 5m. It is worth mentioning that the Vung Ro Bay will be affected by tsunami waves in all simulated scenarios. We quantify the influence of landslide characteristics (volume, water depth and material) and highlight the local effect of coastal bathymetry on the tsunami generation and propagation which lead to different hazard level of SCV coast.</p>

scholarly journals Laboratory investigation of crest height statistics in intermediate water depths

2019 ◽  
Vol 475 (2229) ◽  
pp. 20190183 ◽  
Author(s):  
I. Karmpadakis ◽  
C. Swan ◽  
M. Christou
Keyword(s):  
Water Depth ◽  
Wave Breaking ◽  
Field Data ◽  
Full Range ◽  
Second Order ◽  
Intermediate Water ◽  
Sea State ◽  
Nonlinear Amplification ◽  
Effective Water ◽  
Water Depths

This paper concerns the statistical distribution of the crest heights associated with surface waves in intermediate water depths. The results of a new laboratory study are presented in which data generated in different experimental facilities are used to establish departures from commonly applied statistical distributions. Specifically, the effects of varying sea-state steepness, effective water depth and directional spread are investigated. Following an extensive validation of the experimental data, including direct comparisons to available field data, it is shown that the nonlinear amplification of crest heights above second-order theory observed in steep deep water sea states is equally appropriate to intermediate water depths. These nonlinear amplifications increase with the sea-state steepness and reduce with the directional spread. While the latter effect is undoubtedly important, the present data confirm that significant amplifications above second order (5–10%) are observed for realistic directional spreads. This is consistent with available field data. With further increases in the sea-state steepness, the dissipative effects of wave breaking act to reduce these nonlinear amplifications. While the competing mechanisms of nonlinear amplification and wave breaking are relevant to a full range of water depths, the relative importance of wave breaking increases as the effective water depth reduces.

scholarly journals Foraminifera and Late Cenomanian-Turonian biostratigraphy of the northern palaeobiogeographic district of Western Siberia

Geologos ◽  
2013 ◽  
Vol 19 (3) ◽  
pp. 201-227 ◽  
Author(s):  
Vera Podobina
Keyword(s):  
Species Composition ◽  
Water Depth ◽  
Western Siberia ◽  
Sufficient Data ◽  
The West ◽  
Core Samples ◽  
Canadian Provinces ◽  
Host Rocks ◽  
Siberian Species

Abstract The study of 114 core samples from seven borehole sections of the Van-Eganskaya area in the central part of Western Siberia yielded sufficient data to investigate the Late Cenomanian-Turonian foraminifers, palaeoenvironments, and the Late Cenomanian-Turonian biostratigraphy of this poorly studied area. Two Late Cenomanian foraminifer zones were established, viz. a (lower) Saccammina micra - Ammomarginulina sibirica Zone and an (upper) Trochammina wetteri tumida - Verneuilinoides kansasensis Zone. They reflect changes in the species composition of the foraminifer assemblages and lithology of the host rocks of the Uvatskian Horizon. In the lower part of the upper zone, beds with Gaudryinopsis nanushukensis elongatus are present. The changes in the species composition and lithology of the upper Cenomanian resulted from water-depth variations during the Boreal transgression. Two distinct assemblages and two homonymous zones, viz. the (lower) Gaudryinopsis angustus and the (upper) Pseudoclavulina hastata zones occur in the Turonian clayey cap-rocks of the superimposed Kuznetsovskian Horizon. Comparison of the Late Cenomanian-Turonian assemblages from the West-Siberian and Canadian provinces of the same Arctic palaeobiogeographical realm shows that the West-Siberian species are the same as, and closely related to, Canadian taxa, along with geographical subspecies. This comparison allows a detailed correlation, which results in a precise dating of the foraminifer zones.

Prediction of Water Wave Breaking Height and Depth Using ANFIS

2011 ◽  
Author(s):  
Ehsan Delavari ◽  
Ahmad Reza Mostafa Gharabaghi ◽  
Mohammad Reza Chenaghlou
Keyword(s):  
Wave Height ◽  
Water Depth ◽  
Fuzzy Inference System ◽  
Wave Breaking ◽  
Fuzzy Inference ◽  
Breaking Point ◽  
Empirical Equations ◽  
Anfis Model ◽  
Inference System ◽  
Semi Empirical

Wave height as well as water depth at the breaking point are two basic parameters which are necessary for studying coastal processes. In this paper, the application of Fuzzy Inference System (FIS) and Adaptive Neuro-Fuzzy Inference System (ANFIS) and semi-empirical models are investigated. The data sets used in this study are published laboratory data obtained from regular wave breaking on plane, impermeable slopes collected from 22 sources. Results indicate that the developed ANFIS model provides more accurate and reliable estimation of breaking wave height, compared to semi-empirical equations. However, some of semi-empirical equations provide better predictions of water depth at the breaking point compared to the ANFIS model.

Impact of Rossby Wave Breaking on U.S. West Coast Winter Precipitation during ENSO Events

2013 ◽  
Vol 26 (17) ◽  
pp. 6360-6382 ◽  
Author(s):  
Ju-Mee Ryoo ◽  
Yohai Kaspi ◽  
Darryn W. Waugh ◽  
George N. Kiladis ◽  
Duane E. Waliser ◽  
...  
Keyword(s):  
United States ◽  
West Coast ◽  
El Niño ◽  
Wave Breaking ◽  
El Nino ◽  
The United States ◽  
La Niña ◽  
The West ◽  
La Nina ◽  
Subtropical Jet

Abstract This study demonstrates that water vapor transport and precipitation are largely modulated by the intensity of the subtropical jet, transient eddies, and the location of wave breaking events during the different phases of ENSO. Clear differences are found in the potential vorticity (PV), meteorological fields, and trajectory pathways between the two different phases. Rossby wave breaking events have cyclonic and anticyclonic regimes, with associated differences in the frequency of occurrence and the dynamic response. During La Niña, there is a relatively weak subtropical jet allowing PV to intrude into lower latitudes over the western United States. This induces a large amount of moisture transport inland ahead of the PV intrusions, as well as northward transport to the west of a surface anticyclone. During El Niño, the subtropical jet is relatively strong and is associated with an enhanced cyclonic wave breaking. This is accompanied by a time-mean surface cyclone, which brings zonal moisture transport to the western United States. In both (El Niño and La Niña) phases, there is a high correlation (>0.3–0.7) between upper-level PV at 250 hPa and precipitation over the west coast of the United States with a time lag of 0–1 days. Vertically integrated water vapor fluxes during El Niño are up to 70 kg m−1 s−1 larger than those during La Niña along the west coast of the United States. The zonal and meridional moist static energy flux resembles wave vapor transport patterns, suggesting that they are closely controlled by the large-scale flows and location of wave breaking events during the different phase of ENSO.

scholarly journals Dynamics of Landfalling Atmospheric Rivers over the North Pacific in 30 Years of MERRA Reanalysis

2014 ◽  
Vol 27 (18) ◽  
pp. 7133-7150 ◽  
Author(s):  
Ashley E. Payne ◽  
Gudrun Magnusdottir
Keyword(s):  
Rossby Wave ◽  
West Coast ◽  
Wave Breaking ◽  
Moisture Transport ◽  
Large Scale ◽  
Eastern Pacific ◽  
The West ◽  
Atmospheric Rivers ◽  
Rossby Wave Breaking ◽  
Upper Level

Abstract A large-scale analysis of landfalling atmospheric rivers (ARs) along the west coast of North America and their association with the upper-tropospheric flow is performed for the extended winter (November–March) for the years 1979–2011 using Modern-Era Retrospective Analysis for Research and Applications (MERRA) reanalysis data. The climatology, relationship to the El Niño–Southern Oscillation and the Madden–Julian oscillation, and upper-level characteristics of approximately 750 landfalling ARs are presented based on the 85th percentile of peak daily moisture flux. AR occurrence along the West Coast is dominated by early season events. In composites of upper-level fields during AR occurrences, certain characteristics stand out irrespective of the tropical climate indices. This suggests that extratropical dynamical processes play a key role in AR dynamics. The influence of the large-scale circulation on AR intensity prior to landfall is examined by objectively selecting an extreme subset of 112 landfalling AR dates representing the 95th percentile of strongest cases. Each landfalling AR date that is identified is traced backward in time using a novel semiautomated tracking algorithm based on spatially and temporally connected organized features in integrated moisture transport. Composites of dynamical fields following the eastward progression of ARs show a close relationship of the location of the jet, Rossby wave propagation, and anticyclonic Rossby wave breaking in the upper troposphere of the eastern Pacific and moisture transport in the lower troposphere. Comparison between the strongest and the weakest ARs within the most extreme subset shows differences in both the intensity of moisture transport and the scale and development of anticyclonic Rossby wave breaking in the eastern Pacific.

Design Challenge of the West Nile Delta Gas Development: The Rosetta Channel Crossing

2021 ◽  
Author(s):  
Leonardo Gitahy ◽  
Daniel Manso ◽  
Guilherme Carvalho ◽  
Mark Lewis ◽  
Dario Migliaresi
Keyword(s):  
Nile Delta ◽  
Cost Effective ◽  
The West ◽  
West Nile ◽  
Third Stage ◽  
Final Design ◽  
Complex Engineering ◽  
The Subject ◽  
To Come ◽  
Steep Slopes

Abstract Raven is the third stage of the West Nile Delta development (following Taurus / Libra and Giza / Fayoum) from two BP-operated offshore concession blocks, North Alexandria and West Mediterranean Deepwater. The Raven project included the design of various rigid pipelines, of which one specifically is the subject of this paper. The 16" RSM to RP in-field flowline is approximately 4.8 km long, connecting a manifold (RSM) to a PLEM (RP) through a route that crosses a prominent geological feature identified as the Rosetta Channel, a submerged canyon that extends for about 30 km. The Rosetta Channel is about 2.5 km wide at the location of the 16" flowline route crossing, with steep slopes going down for approx. 40m (in height) on the RSM side, and then climbing up approx. 150m (in height) towards the RP side. Although it is typically preferred to avoid very rough geophysical features, this is not always possible or practicable and it is not uncommon to come across challenging seabed features that demand complex engineering solutions in order to minimise risks and associated costs. This paper addresses the numerous technical challenges involved in the design of the 16" flowline that crosses the Rosetta Channel. Following close collaboration between all involved stakeholders, a robust, reliable and cost-effective solution was achieved after a detailed engineering process, where the final design required a unique combination of mitigations including seabed excavation, pre-lay rock carpets, post-lay rock berms, cable jetting, curve bollards and sleepers.

COASTAL MODELING FOR REGIONAL SEDIMENT BUDGET IN WEST MAUI, HAWAII

2017 ◽  
pp. 14
Author(s):  
Lihwa Lin ◽  
Zeki Demirbilek ◽  
Jessica Podoski ◽  
Thomas Smith ◽  
Lihwa Lin
Keyword(s):  
Sediment Transport ◽  
Wave Breaking ◽  
Wave Climate ◽  
Mountainous Terrain ◽  
The West ◽  
Coastal Modeling ◽  
Eddy Formation ◽  
Coastal Margin ◽  
Limited Supply ◽  
Offshore Wave

The West Maui Region incorporates a thin coastal margin backed by steep mountainous terrain that has been vastly altered by agricultural and urbanized development. Coastline includes headlands and reefs with a very limited supply of sediment. Shoreline was found to be erosional chronically based on average rates. The dynamics of the area are complex with a wave climate affected by intricate bathymetry, wind, and island sheltering. Longshore currents vary locally and temporally from nearshore to offshore. Wave and current modeling indicates that large waves in the summer and winter have driven the majority of sediment transport along the coast. The littoral transport is essentially northward in summer and southward in winter. The net transport of longshore sediment is overall small. The nearshore eddy formation with wave breaking nearshore over narrow sandy bed and wide reefs may increase the complexity of sediment movement within the region.

scholarly journals Estimation of Wave-Breaking Index by Learning Nonlinear Relation Using Multilayer Neural Network

2022 ◽  
Vol 10 (1) ◽  
pp. 50
Author(s):  
Miyoung Yun ◽  
Jinah Kim ◽  
Kideok Do
Keyword(s):  
Neural Network ◽  
Wave Height ◽  
Water Depth ◽  
Wave Breaking ◽  
Water Wave ◽  
Breaking Wave ◽  
Empirical Equations ◽  
Bottom Slope ◽  
Proposed Model ◽  
Deep Water Wave

Estimating wave-breaking indexes such as wave height and water depth is essential to understanding the location and scale of the breaking wave. Therefore, numerous wave-flume laboratory experiments have been conducted to develop empirical wave-breaking formulas. However, the nonlinearity between the parameters has not been fully incorporated into the empirical equations. Thus, this study proposes a multilayer neural network utilizing the nonlinear activation function and backpropagation to extract nonlinear relationships. Existing laboratory experiment data for the monochromatic regular wave are used to train the proposed network. Specifically, the bottom slope, deep-water wave height and wave period are plugged in as the input values that simultaneously estimate the breaking-wave height and wave-breaking location. Typical empirical equations employ deep-water wave height and length as input variables to predict the breaking-wave height and water depth. A newly proposed model directly utilizes breaking-wave height and water depth without nondimensionalization. Thus, the applicability can be significantly improved. The estimated wave-breaking index is statistically verified using the bias, root-mean-square errors, and Pearson correlation coefficient. The performance of the proposed model is better than existing breaking-wave-index formulas as well as having robust applicability to laboratory experiment conditions, such as wave condition, bottom slope, and experimental scale.

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