scholarly journals Spatial distribution of macroalgae along the shores of Kongsfjorden (West Spitsbergen) using acoustic imaging

2017 ◽  
Vol 38 (2) ◽  
pp. 205-229 ◽  
Author(s):  
Aleksandra Kruss ◽  
Jarosław Tęgowski ◽  
Agnieszka Tatarek ◽  
Józef Wiktor ◽  
Philippe Blondel
Keyword(s):  
Benthic Communities ◽  
Euphotic Zone ◽  
Acoustic Imaging ◽  
The Arctic ◽  
Acoustic Data ◽  
Crucial Component ◽  
Acoustic Methods ◽  
Arctic Conditions ◽  
Biological Sampling ◽  
West Spitsbergen

Abstract The identification of macroalgal beds is a crucial component for the description of fjord ecosystems. Direct, biological sampling is still the most popular investigation technique but acoustic methods are becoming increasingly recognized as a very efficient tool for the assessment of benthic communities. In 2007 we carried out the first acoustic survey of the littoral areas in Kongsfjorden. A 2.68 km2 area comprised within a 12.40 km2 euphotic zone was mapped along the fjord’s coast using single- and multi-beam echosounders. The singlebeam echosounder (SBES) proved to be a very efficient and reliable tool for macroalgae detection in Arctic conditions. The multibeam echosounder (MBES) was very useful in extending the SBES survey range, even though it’s ability in discriminating benthic communities was limited. The final result of our investigation is a map of the macroalgae distribution around the fjord, showing 39% macroalgae coverage (1.09 km2) of investigated area between isobaths -0.70 m and -30 m. Zonation analysis showed that most of the studied macroalgae areas occur up to 15 m depth (93%). These results were confirmed by biological sampling and observation in key areas. The potential of acoustic imaging of macrophytes, and a proposed methodology for the processing of acoustic data, are presented in this paper along with preliminary studies on the acoustic reflectivity of macroalgae, also highlighting differences among species. These results can be applied to future monitoring of the evolution of kelp beds in different areas of the Arctic, and in the rest of the world.

scholarly journals Diversity of Arctic pelagic <i>Bacteria</i> with an emphasis on photoheterotrophs: a review

2014 ◽  
Vol 11 (12) ◽  
pp. 3309-3322 ◽  
Author(s):  
D. Boeuf ◽  
F. Humily ◽  
C. Jeanthon
Keyword(s):  
Arctic Ocean ◽  
Heterotrophic Bacteria ◽  
Euphotic Zone ◽  
The Arctic ◽  
Major Influence ◽  
Distinctive Features ◽  
Ice Melt ◽  
Energy Needs ◽  
Continental Shelves ◽  
The Arctic Ocean

Abstract. The Arctic Ocean is a unique marine environment with respect to seasonality of light, temperature, perennial ice cover, and strong stratification. Other important distinctive features are the influence of extensive continental shelves and its interactions with Atlantic and Pacific water masses and freshwater from sea ice melt and rivers. These characteristics have major influence on the biological and biogeochemical processes occurring in this complex natural system. Heterotrophic bacteria are crucial components of marine food webs and have key roles in controlling carbon fluxes in the oceans. Although it was previously thought that these organisms relied on the organic carbon in seawater for all of their energy needs, several recent discoveries now suggest that pelagic bacteria can depart from a strictly heterotrophic lifestyle by obtaining energy through unconventional mechanisms that are linked to the penetration of sunlight into surface waters. These photoheterotrophic mechanisms may play a significant role in the energy budget in the euphotic zone of marine environments. Modifications of light and carbon availability triggered by climate change may favor the photoheterotrophic lifestyle. Here we review advances in our knowledge of the diversity of marine photoheterotrophic bacteria and discuss their significance in the Arctic Ocean gained in the framework of the Malina cruise.

On the Problems of SLAM Simulation for Mobile Robots in the Arctic Conditions

2020 ◽  
pp. 34-44
Author(s):  
Elvira Chebotareva ◽  
Tatyana Tsoy ◽  
Bulat Abbyasov ◽  
Jamila Mustafina ◽  
Edgar A. Martinez-Garcia ◽  
...  
Keyword(s):  
Mobile Robots ◽  
The Arctic ◽  
Arctic Conditions

scholarly journals Polymer Nanocomposites Exploited Under The Arctic Conditions

2016 ◽  
Vol 1 (1) ◽  
pp. 122 ◽  
Author(s):  
A.A. Okhlopkova ◽  
L.A. Nikiforov ◽  
T.A. Okhlopkova ◽  
R.V. Borisova
Keyword(s):  
Molecular Weight ◽  
Mechanical Activation ◽  
High Molecular Weight ◽  
Polymer Matrix ◽  
Planetary Mill ◽  
Layered Silicates ◽  
The Arctic ◽  
Liquid Media ◽  
Arctic Conditions ◽  
Ultra High Molecular Weight

<p>Several technologies of the preparation of nanocomposites based on ultra-high-molecular-weight polyethylene were developed. The first technology is based on mechanical activation of layered silicates with surfactant before addition into polymer matrix. The second technology represents mixing of ultra-high-molecular-weight polyethylene with nanoparticles by joint mechanical activation in a planetary mill. The third technology is based on mixing of ultra-high-molecular-weight polyethylene with nanoparticles in liquid media under continuous ultrasonic treatment. Common features of these technologies are reaching of filler uniform distribution in a polymer matrix and significant improvement in the mechanical properties. Also, supramolecular structure of the composites was studied.</p>

scholarly journals Optimal Ways of Unloading and Loading Operations under Arctic Conditions

2021 ◽  
Vol 9 (10) ◽  
pp. 1050
Author(s):  
Marat Eseev ◽  
Dmitry Makarov
Keyword(s):  
Mathematical Modeling ◽  
Geographical Location ◽  
Geographic Location ◽  
Economic Benefits ◽  
Transport Infrastructure ◽  
The Arctic ◽  
Cargo Delivery ◽  
Arctic Conditions ◽  
Loading And Unloading ◽  
The Right

Usually, loading and unloading of cargo ships takes place in ports that are equipped with the infrastructure necessary to carry out such operations. In the Arctic, often a helicopter is the only way to get the cargo to the right place. Finding the optimal geographic location for unloading a ship using helicopters is an important task. It is necessary to create a support system for making the right decisions in such situations. Mathematical modeling has been used to find the geographical location that ensures the most favorable and quickest delivery of cargo from a vessel to its destination, using a helicopter. A criterion has also been found in which the search for the optimum point is a more rational way of unloading the vessel compared to other discharge options. The maps of the economic benefits of loading and unloading operations in this model have been developed. Using the example of the developed model, it is shown that during the transportation of goods in Ob Bay, significant economic and temporary advantages can be obtained. The developed model can be extended to the case of cargo delivery not only in the Arctic conditions, but also where the transport infrastructure is insufficiently developed.

Chapter 20 Paleogene history

1997 ◽  
Vol 17 (1) ◽  
pp. 388-417
Keyword(s):  
Early Cretaceous ◽  
The Arctic ◽  
North Coast ◽  
Western Coast ◽  
Central Basin ◽  
Oblique Collision ◽  
The North ◽  
Western Border ◽  
Paleozoic Rocks ◽  
West Spitsbergen

The Paleogene chapter of Svalbard history is a quite distinct one. It begins with an unconformity, albeit a sub-parallel one representing a late Cretaceous hiatus. Resting on Albian and older strata, the Van Mijenfjorden Group of six formations totals a thickness of about 2500 m in the Central Basin of Spitsbergen. The outcrop is ringed by Early Cretaceous strata in a broad syncline (Fig. 20.1). The strata are largely non-marine, coal-bearing sandstones, with interbedded marine shales and they range in age through Paleocene and Eocene.From latest Paleocene through Eocene time the West Spitsbergen Orogeny caused (Spitsbergian) deformation along the western border of the Central Basin, but it is most conspicuous in the folding and thrusting of Carboniferous through Early Cretaceous rocks. The orogen extended westwards to and beyond the western coast of central and southern Spitsbergen including Precambrian and Early Paleozoic rocks, which had already been involved in earlier tectogenesis. The eastward-verging thrusting extended beneath the Tertiary basin and reactivated older faults to the east.In the wider context Svalbard, adjacent to the north coast of Greenland, had been an integral part of Pangea from Carboniferous through Cretaceous time. The northward extension of the Atlantic opening reached and initiated the spreading of the Arctic Eurasia Basin at the beginning of the Paleogene Period. This led to the separation of Svalbard together with the Barents Shelf and northern Europe from Greenland by dextral strike-slip transform faulting. In the course of this progression, oblique collision between northeast Greenland and Svalbard caused

ESTIMATION OF PECULIARITIES OF TEMPERATURE INVERSION FORMATION IN OPEN MINING IN THE ARCTIC CONDITIONS

2021 ◽  
Vol 4 (1) ◽  
pp. 59-75
Author(s):  
S.G. Gendler ◽  
◽  
I.A. Borisovskiy ◽  
Keyword(s):  
Temperature Inversion ◽  
Open Pit ◽  
The Arctic ◽  
Effect Of Temperature ◽  
Ansys Fluent ◽  
Air Masses ◽  
Steady State Temperature ◽  
Arctic Conditions ◽  
Air Layers ◽  
Fluent Software

The article presents the results of studies on the study of the effect of temperature in-versions on the efficiency of ventilation of a quarry space. It was found that a negative tem-perature difference leads to cooling of the surface air layers, which can cause the accumula-tion of cooled air masses in the lower part of the open pit and a decrease in the intensity of air exchange. It is shown that the assessment of the peculiarities of the formation of the pa-rameters of the mine atmosphere and the substantiation of the boundaries of the use of natu-ral ventilation of gold-ore quarries, taking into account the steady-state temperature gradi-ent, can be carried out using mathematical modeling based on the Ansys Fluent software package.

Promising use of high-strength nitrogen steel for the ice belt of marine machinery operating in the extreme arctic conditions

2021 ◽  
pp. 229-237
Author(s):  
A. A. Deev ◽  
G. Yu. Kalinin ◽  
K. E. Sadkin
Keyword(s):  
Physical And Mechanical Properties ◽  
High Strength ◽  
The Arctic ◽  
Welded Steel ◽  
Corrosion Resistant ◽  
Critical Elements ◽  
Steel Sheets ◽  
Nitrogen Steel ◽  
Arctic Conditions ◽  
Clad Steel

This article shows the possibility of using high-strength nitrogen-containing corrosion-resistant steel grade 04Kh20N6G11M2AFB for the construction of critical elements and units of marine equipment operating at low temperatures, including the Arctic. The advantages of nitrogen-containing steel over clad steel AB2 + 08Kh18N10T always used in shipbuilding and welded steel of F500W category are considered. According to the assessment of testing of homogeneous nitrogen steel sheets, the level of its physical and mechanical properties exceeds the analogous parameters of traditional AB2 + 08Kh18N10T steels in a wide temperature range, up to –90°C.

scholarly journals Benthic Communities on the Mohn’s Treasure Mound: Implications for Management of Seabed Mining in the Arctic Mid-Ocean Ridge

2020 ◽  
Vol 7 ◽  
Author(s):  
Eva Ramirez-Llodra ◽  
Ana Hilario ◽  
Emil Paulsen ◽  
Carolina Ventura Costa ◽  
Torkild Bakken ◽  
...  
Keyword(s):  
Benthic Communities ◽  
The Arctic ◽  
Mid Ocean Ridge ◽  
Ocean Ridge ◽  
Seabed Mining

scholarly journals Frontal structures in the West Spitsbergen Current margins

Ocean Science ◽  
2013 ◽  
Vol 9 (6) ◽  
pp. 957-975 ◽  
Author(s):  
W. Walczowski
Keyword(s):  
Thermohaline Circulation ◽  
Baroclinic Instability ◽  
Atlantic Water ◽  
Transport Processes ◽  
The Arctic ◽  
The West ◽  
Jet Streams ◽  
Nordic Seas ◽  
Western Border ◽  
West Spitsbergen

Abstract. The structures of the hydrographic fronts separating the Atlantic-origin waters from ambient waters in the northern Nordic Seas are discussed. Flows of the western and eastern branches of the West Spitsbergen Current create the Atlantic domain borders and maintain these fronts. This work is based on previous research and on investigations carried out in the project DAMOCLES (Developing Arctic Modelling and Observational Capabilities for Long-term Environmental Studies). Most of the observational data were collected during the R/V Oceania cruises. The main focus of the paper is the western border of the Atlantic domain – the Arctic Front, alongfrontal and transfrontal transports, and the front instability and variability. The alongfrontal baroclinic jet streams were described as a significant source of the Atlantic Water and heat in the Nordic Seas. The baroclinic instability and advection of baroclinic eddies which occurs due to this instability were found to be the main transfrontal transport processes. Most of the Atlantic Water transported by the western branch recirculates west and southward. The eastern branch of the West Spitsbergen Current provides most of the Atlantic Water entering the Arctic Ocean. Both processes are very important for the Arctic and global thermohaline circulation.

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