Luminous Phenomena accompanying Destructive Sea-waves (Tunami)

Coastal area of Bitung Municipality is one of the economical activities centers in North Sulawesi Province such as for land-uses and the exploitation of natural resources. Those activities are exaggerating day bay day and tended to be uncontrollable. The excess of those conditions, it has been recorded the change of waves in Bitung waters that has impacts to coastal areas and can affect the utilization of coastal and marine resources. This research was aimed to observe waves altitude variations in Bitung waters with Svedrup Munk and Bretchsneider (SMB) method that had been used to predict waves altitudes. The results showed that the wind speed during West Season was 0.33 m and were dominant to the East, while during East season was 0.91m from South-East to North-West, and then on transition period (March to May) was 1.08m from South-East to East. The results of those wind speed to the waves altitudes in Bitung waters is discussed in this paper© Pesisir pantai Kota Bitung merupakan salah satu pusat aktivitas ekonomi (misalnya pemanfaatan lahan dan eksploitasi sumberdaya) di Provinsi Sulawesi Utara. Aktivitas tersebut semakin hari semakin meningkat dan memiliki kecenderungan tidak terkontrol. Akibat dari keadaan tersebut, telah terjadi perubahan fenomena gelombang di perairan Bitung yang berdampak pada keberadaan daerah pesisir pantai di mana hal ini dapat mengganggu aktivitas pemanfaatan sumberdaya pesisir dan laut tersebut. Penelitian ini bertujuan untuk mengetahui variasi tinggi gelombang di perairan Bitung dengan menggunakan metode Svedrup Munk and Bretchsneider (SMB) yang biasa digunakan untuk peramalan tinggi gelombang signifikan. Hasil penelitian menunjukkan bahwa kecepatan angin pada Musim Barat sebesar 0,33 meter dan dominan ke arah Timur, sementara pada Musim Timur sebesar 0,91 meter dari arah Tenggara ke Barat Laut, serta pada Musim Peralihan (antara bulan Maret-Mei) adalah sebesar 1,08 meter dari arah Tenggara dan Timur. Pengaruh kecepatan angin tersebut terhadap gelombang laut di perairan Bitung dibahas dalam tulisan ini©

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Mapping of landscape-morphological structure of the Northern-Western part of Anapa bay bar by digital high resolution aerial images

Geodesy and Cartography ◽

10.22389/0016-7126-2017-927-9-22-29 ◽

2017 ◽

Vol 927 (9) ◽

pp. 22-29

Author(s):

V.I. Kravtsovа ◽

E.R. Chalova

Keyword(s):

High Resolution ◽

Morphological Structure ◽

Middle Part ◽

Aerial Images ◽

Medical Resource ◽

Sea Waves ◽

Coast Line ◽

Waves Interaction ◽

Account Due ◽

Digital Landscape

Anapa bay bar is a valuable recreational-medical resource. Digital landscape-morphological mapping of its the Northern-Western part was created by digital aero survey materials for monitoring of its statement. Compiled maps show that in the Western part of region dune belt is degradated, front dune hills destroyed due to spreading of settlement Veselovka buildings to beach, and due to mass enactments carrying out at bay bar of lake Solenoe. Here it is necessary to decide the problem of defense from waves flooding by construction of artificial hills. The middle part of region, around Bugaz lagoon, is using for unregulated recreation of extreme sportsmen – windsurfing and kiting – with seasonal recreation in camping from tent-city and campers. Many short roads to sea beach, orthogonal to coast line, have been transformed to corridors of blowing and sea waves interaction to lagoon lowland with dune belt destroying. In the Eastern part of region, at Bugaz bay bar, dune belt is conserve, it changes under natural sea and wind processes action. At some places sea waves are erode windward front dune slope. Just everywhere sand accumulative trains are forming at leeward slope of front dune. Showed peculiarities of landscape morphological structure mast be taken in account due treatment of measures for bay bar defense and keeping.

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Characteristics of Sea Waves Condition at The Northern and Eastern of Bintan Island within Period of 2015-2019

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/695/1/012038 ◽

2021 ◽

Vol 695 (1) ◽

pp. 012038

Author(s):

M. P. Suhana ◽

L. F. Shafitri ◽

R. D. Putra ◽

A. H. Nugraha ◽

C. J. Koenawan ◽

...

Keyword(s):

Sea Waves

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Settling Velocity of Microplastics Exposed to Wave Action

Journal of Marine Science and Engineering ◽

10.3390/jmse9020142 ◽

2021 ◽

Vol 9 (2) ◽

pp. 142

Author(s):

Annalisa De Leo ◽

Laura Cutroneo ◽

Damien Sous ◽

Alessandro Stocchino

Keyword(s):

Laboratory Experiments ◽

Settling Velocity ◽

Transport Model ◽

Stokes Drift ◽

Inertial Effects ◽

Sea Waves ◽

Heavy Particles ◽

Analytical Formulation ◽

Simplified Approach ◽

Remote Areas

Microplastic (MP) debris is recognized to be one of the most serious threats to marine environments. They are found in all seas and oceanic basins worldwide, even in the most remote areas. This is further proof that the transport of MPs is very efficient. In the present study, we focus our attention on MPs’ transport owing to the Stokes drift generated by sea waves. Recent studies have shown that the interaction between heavy particles and Stokes drift leads to unexpected phenomena mostly related to inertial effects. We perform a series of laboratory experiments with the aim to directly measure MPs’ trajectories under different wave conditions. The main objective is to quantify the inertial effect and, ultimately, suggest a new analytical formulation for the net settling velocity. The latter formula might be implemented in a larger scale transport model in order to account for inertial effects in a simplified approach.

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Analysis of Dangerous Sea States in the Northwestern Mediterranean Area

Journal of Marine Science and Engineering ◽

10.3390/jmse9040422 ◽

2021 ◽

Vol 9 (4) ◽

pp. 422

Author(s):

Alessio Innocenti ◽

Miguel Onorato ◽

Carlo Brandini

Keyword(s):

Extreme Events ◽

Mediterranean Area ◽

Rayleigh Distribution ◽

Surface Elevation ◽

Wave Steepness ◽

Sea Waves ◽

Operational Forecasts ◽

Long Time ◽

Simulated Field

Extreme sea waves, although rare, can be notably dangerous when associated with energetic sea states and can generate risks for the navigation. In the last few years, they have been the object of extensive research from the scientific community that helped with understanding the main physical aspects; however, the estimate of extreme waves probability in operational forecasts is still debated. In this study, we analyzed a number of sea-states that occurred in a precise area of the Mediterranean sea, near the location of a reported accident, with the objective of relating the probability of extreme events with different sea state conditions. For this purpose, we performed phase-resolving simulations of wave spectra obtained from a WaveWatch III hindcast, using a Higher Order Spectral Method. We produced statistics of the sea-surface elevation field, calculating crest distributions and the probability of extreme events from the analysis of a long time-series of the surface elevation. We found a good matching between the distributions of the numerically simulated field and theory, namely Tayfun second- and third- order ones, in contrast with a significant underestimate given by the Rayleigh distribution. We then related spectral quantities like angular spreading and wave steepness to the probability of occurrence of extreme events finding an enhanced probability for high mean steepness seas and narrow spectra, in accordance with literature results, finding also that the case study of the reported accident was not amongst the most dangerous. Finally, we related the skewness and kurtosis of the surface elevation to the wave steepness to explain the discrepancy between theoretical and numerical distributions.

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Experimental Investigation on Floating Solar-Driven Membrane Distillation Desalination Modules

Membranes ◽

10.3390/membranes11050304 ◽

2021 ◽

Vol 11 (5) ◽

pp. 304

Author(s):

Qingxiu Miao ◽

Yaoling Zhang ◽

Shuo Cong ◽

Fei Guo

Keyword(s):

Power Source ◽

Membrane Distillation ◽

Small Scale ◽

Sea Waves ◽

Permeate Flux ◽

Practical Application ◽

Rejection Ratio ◽

Cold Source ◽

Mild Temperature ◽

Feed Temperature

Membrane distillation (MD) processes need a relatively mild temperature gradient as the driving force for desalination. In the field, it is reasonable to utilize solar energy as the heat source for the feed, and seawater as the infinite cold source for condensation. Solar-driven MD provides a route for the practical application of seawater desalination at a small scale. In this work, we focus on floating MD modules with a solar heating bag as the power source, and perform proof-of-principle experiments on the MD performance under various conditioning parameters, including feed flow rate, feed temperature, salinity, air gap, and sea waves. The results indicate that floating solar-driven MD modules are feasible in terms of permeate flux and salt rejection ratio, and the upward evaporation MD configuration leads to a better performance in terms of permeate flux. The simulation and experiments also show that the natural sea waves disturb the heating bag and the MD module floating on the surface of seawater, and effectively enhance the feed circulation and transport in the system.

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Mineralogy, Geochemistry and Provenance of Coastal Sands from Greece: New Insights on the REE Content of Black Coastal Sands from Aggelochori Area, N.-Greece

Minerals ◽

10.3390/min11070693 ◽

2021 ◽

Vol 11 (7) ◽

pp. 693

Author(s):

Argyrios Papadopoulos ◽

Stylianos Lazaridis ◽

Afroditi Kipourou-Panagiotou ◽

Nikolaos Kantiranis ◽

Antonios Koroneos ◽

...

Keyword(s):

Major And Trace Elements ◽

Heavy Minerals ◽

Sea Waves ◽

Complex Flow ◽

Fine Grained ◽

Microscopy Analysis ◽

Beach Sands ◽

Geochemical Analyses ◽

The One ◽

Black Color

Beach sands from Aggelochori coast line are investigated for their geochemistry and REE content, mineralogy and their provenance. These fluvial sands bear heavy minerals enriched horizons (containing minerals such as magnetite, zircon, ilmenite, hematite, rutile and titanite) that can be distinguished due to their black color and are formed usually due to the action of sea waves that deposit the heavy minerals and remove the lighter ones. After a suitable processing (washing, sieving, drying and magnetic separation) of the samples, the mineral constituents and their presence (wt.%) were estimated by XRD. Among the samples, the one being simultaneously the more fine grained and the more zircon-enriched (as suggested by XRPD data and optical microscopy analysis) has been selected for further geochemical analyses. The major and trace elements contents were compared to previously studied REE enriched beach sands from Kavala and Sithonia. Beach sands from Aggelochori area appear to have relatively low REE contents. Considering the provenance of these sediments, we suggest that these sands, are a product of the erosion of multi-sources, including the near-by Monopigado granite, as well as metamorphic rocks, as indicated by the presence of rutile and both ilmenite and magnetite in some samples. Therefore, there are indications of a complex flow pattern that existed at the paleo-catchment area of the deposition.

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