The Mineral Composition of the Modern Fenland Silt, with special reference to Carbonate Minerals

1920 ◽  
Vol 57 (12) ◽  
pp. 543-551 ◽  
Author(s):  
F. Hardy
Keyword(s):  
Chemical Analysis ◽  
Mineral Composition ◽  
Mineral Assemblage ◽  
Sea Water ◽  
Mineralogical Composition ◽  
The North ◽  
The North Sea ◽  
Recent Origin ◽  
Boulder Clay ◽  
Sea Currents

SUMMARY1. A sample of modern Fenland silt containing 8·98 per cent of carbonate was found on minaralogical examination to include dolomite as well as aragonite in its mineral assemblage.2. The dolomite is present in fresh angular crystal grains which suggest a secondary and recent origin of the mineral. It has possibly been deposited from sea-water which periodically covers the foreshore of the Fenland border of the Wash.3. The general mineral composition of the silt resembles closely that of certain geologically recent deposits of Cambridgeshire, and points to the boulder-clay left by the North Sea glacier as the chief source of the material of which the silt is composed. The silt has mainly been deposited by sea-currents which carry southwards the eroded glacial deposits of the South Yorkshire and North Licoln-shire coasts.4. An attempt is made to interpret the results of a chemical analysis of the silt in the light of its mineralogical composition, chiefly with regard to carbonate, potash, and phosphate. Muscovite, is found to be the main source of potash, and apatite of phosphate in the silt.

scholarly journals An ensemble study of extreme storm surge related water levels in the North Sea in a changing climate

Ocean Science ◽  
2009 ◽  
Vol 5 (3) ◽  
pp. 369-378 ◽  
Author(s):  
A. Sterl ◽  
H. van den Brink ◽  
H. de Vries ◽  
R. Haarsma ◽  
E. van Meijgaard
Keyword(s):  
North Sea ◽  
Climate Model ◽  
Sea Water ◽  
Global Climate ◽  
Global Climate Model ◽  
Storm Surges ◽  
Water Levels ◽  
The North ◽  
Extreme Storm ◽  
The North Sea

Abstract. The height of storm surges is extremely important for a low-lying country like The Netherlands. By law, part of the coastal defence system has to withstand a water level that on average occurs only once every 10 000 years. The question then arises whether and how climate change affects the heights of extreme storm surges. Published research points to only small changes. However, due to the limited amount of data available results are usually limited to relatively frequent extremes like the annual 99%-ile. We here report on results from a 17-member ensemble of North Sea water levels spaning the period 1950–2100. It was created by forcing a surge model of the North Sea with meteorological output from a state-of-the-art global climate model which has been driven by greenhouse gas emissions following the SRES A1b scenario. The large ensemble size enables us to calculate 10 000 year return water levels with a low statistical uncertainty. In the one model used in this study, we find no statistically significant change in the 10 000 year return values of surge heights along the Dutch during the 21st century. Also a higher sea level resulting from global warming does not impact the height of the storm surges. As a side effect of our simulations we also obtain results on the interplay between surge and tide.

Pollution of the Outer Oslofjord

1991 ◽  
Vol 24 (10) ◽  
pp. 321-322
Author(s):  
Kjell Baalsrud
Keyword(s):  
North Sea ◽  
General Circulation ◽  
Sea Water ◽  
Sewage Treatment ◽  
Circulation Pattern ◽  
Polluted Water ◽  
The North ◽  
Recreation Area ◽  
The North Sea ◽  
Sill Depth

The Outer Oslofjord has recently been subject to concern. 1. The Inner Oslofjord. Covers an area of 193 km2, is 160 m deep and is separated from the Outer Oslofjord by the narrow Drøbak sound with a sill depth of less than 20 metres. This part of the Oslofjord constitutes an enclosed body of sea water, sensitive to pollution, receiving sewage from approximately 650,000 inhabitants. In spite of modern sewage treatment, the fjord still suffers torn eutrophication problems resulting in reduced oxygen in the deep water, and areas of anoxic bottom water. The fjord is an important recreation area. 2. The Outer Oslofjord. Recent findings indicate that eutrophication is slowly increasing. An increasing eutrophication of the Outer Oslofjord wil also increase the need (and cost) of better sewage treatment in the Inner Oslofjord. 3. The North Sea. The quality of the water in the Oslofjord area is also dependent on the water it receives from the Skagerrak. The Skagerrak water will periodically receive polluted water from the southern North Sea and Kattegat. When these episodes coincide with water renewals between the Oslofjord and the Skagerrak, the fjord will receive polluted water from other countries. The Oslofjord water will in turn discharge into the Skagerrak, but due to the general circulation pattern, this will mainly influence the Norwegian south-east coast.

scholarly journals A Note on the Water Movements in the English Channel and Neighbouring Seas, considered on the Basis of Salinity Distribution.

1925 ◽  
Vol 13 (3) ◽  
pp. 670-672 ◽  
Author(s):  
J. R. Lumby
Keyword(s):  
Sea Water ◽  
Water Movement ◽  
Atlantic Water ◽  
Irish Sea ◽  
English Channel ◽  
Southern Bight ◽  
The North ◽  
The North Sea ◽  
Normal Water ◽  
The Irish Sea

Comparison of the conceptions which have hitherto been held in regard to the hydrography of the English Channel with those which are offered as a result of the recent activities of the Atlantic Slope Committee, shows that a difference exists which, in the writer's opinion, lies in the interpretation of the material, rather than in the fundamental differences in the material itself. For example, it is stated that the physical character of the water in the English Channel is conditioned, especially in the summer months, by that of the North Sea water rather than by that of the Atlantic water. “En plein été, en août, les eaux chaudes de la mer du Nord affluent dans la Manche.” A similar regimen is suggested for the waters of the Irish Sea, which are said to be derived from the northward. Carruthers shows that the normal water movement in the eastern part of the English Channel is through Dover Straits into the Southern Bight, this movement appearing to be more persistent along the bottom than on the surface. Furthermore, one of the two months in which reversal of this direction appears least likely to occur is August.

scholarly journals III.—On the Structure of the Valleys of the Blackwater and the Crough, and of the East Essex Gravel, and on the Relation of this Gravel to the Denudation of the Weald

1866 ◽  
Vol 3 (26) ◽  
pp. 348-354 ◽  
Author(s):  
Searles V. Wood
Keyword(s):  
North Sea ◽  
Glacial Period ◽  
The South ◽  
Northern Boundary ◽  
The North ◽  
Complete Order ◽  
The North Sea ◽  
Boulder Clay ◽  
London Clay

In a paper in this Magazine, upon the structure of the Thames Valley, I endeavoured to show that instead of being, as had been asserted, a valley of similar structure to those of the Somme and Seine, and containing deposits of nearly similar order and age, the valley in which the Thames gravel was deposited possessed no outlet to what is now the North Sea, being divided from it by a range of high gravelless country; and that, in lieu of such an outlet, the valley opened, in more than one part, over what is now the bare Chalk country forming the northern boundary of the Valley of the Weald. I also endeavoured to show that all the deposits of the Thames Valley, except the peat and marsh clay, belonged to several successive stages, marking the gradual denudation of the Boulderclay, the lower Bagshot, the London Clay, and the subjacent Tertiaries, which had, at the end of the Glacial period, spread over the south-east of England in a complete order of succession: the sea into which this valley discharged occupying, what is now, the Chalk country of the Counties of Kent, Surrey, Sussex, and Hampshire, inclusive of the interval subsequently scooped out to form the Valley of the Weald: so that, not only was the latter valley newer than that of the Thames, and of the most recent of the Thames Valley deposits, except the peat and marsh clay, but that these deposits in themselves marked a long descent in time from that comparatively remote period of the Boulder-clay.

scholarly journals Seasonal variations in the occurrence of Vibriovulnificusalong the Dutch coast

1994 ◽  
Vol 112 (2) ◽  
pp. 285-290 ◽  
Author(s):  
J. Veenstra ◽  
P. J. G. M. Rietra ◽  
J. M. Coster ◽  
E. Slaats ◽  
S. Dirks-Go
Keyword(s):  
Seasonal Variation ◽  
Water Temperature ◽  
North Sea ◽  
Seasonal Variations ◽  
Water Samples ◽  
Human Disease ◽  
Sea Water ◽  
Dutch Coast ◽  
The North ◽  
The North Sea

SUMMARYThe seasonal variation in the occurrence ofV. vulnificusin relation to water temperature and salinity was studied along the Dutch coast. In two consecutive yearsV. vulnificusstrains could be isolated in August when the water temperature was highest. The indole-positive strains isolated from North Sea water samples were identical to most strains isolated from human disease and from the environment. However, strains isolated from four of five patients living in countries around the North Sea were different from the North Sea isolates in that they were indole-negative and have a lower NaCl tolerance.

The Lateral Boundaries of the Continental Shelf and the Judgment of the International Court of Justice in the North Sea Continental Shelf Cases

1970 ◽  
Vol 64 (3) ◽  
pp. 562-593 ◽  
Author(s):  
Etienne Grisel
Keyword(s):  
Continental Shelf ◽  
International Law ◽  
International Court Of Justice ◽  
Customary International Law ◽  
Exclusive Jurisdiction ◽  
The North ◽  
Sea Bottom ◽  
International Court ◽  
The North Sea ◽  
Recent Origin

A rule of customary international law of recent origin has conferred sovereign rights over the continental shelf to individual states for the limited purposes of exploration and exploitation. The attribution of such exclusive jurisdiction required the delimitation of boundaries between the submarine areas appertaining to various littoral states. The importance of such partition of the seabed and subsoil is self-evident, but two points do call for comment. First, since the shelf may be considerably extended in the future according to the criterion of exploitability, the method now adopted will have a constantly growing significance. Second, the acquisition of the sea bottom by coastal nations has created inequalities between them, depending on their relative degree of technical development as well as on their geographical circumstances. The drawing of boundaries separating their respective shelves can aggravate or diminish these inequalities.

Annual and spatial variability in endo- and ectoparasite infections of North Sea cod (Gadus morhua Linnaeus, 1758) larvae, post-larvae and juveniles

2014 ◽  
Vol 59 (2) ◽  
Author(s):  
Foojan Mehrdana ◽  
Qusay Bahlool ◽  
Alf Skovgaard ◽  
Jesper Kuhn ◽  
Per Kania ◽  
...  
Keyword(s):  
Spatial Variability ◽  
North Sea ◽  
Gadus Morhua ◽  
Sea Water ◽  
Atlantic Cod ◽  
The North ◽  
Infection Pressure ◽  
High Prevalence ◽  
Atlantic Cod Larvae ◽  
The North Sea

AbstractA parasitological investigation was performed on a total of 5380 Atlantic cod larvae, post-larvae and small juveniles sampled from the North Sea during a period of five years. The copepod Caligus elongatus (Von Nordmann, 1832) and the nematode Hysterothylacium aduncum (Rudolphi, 1802) were found at a relatively high prevalence of infection (4.6% and 5.2%, respectively). The infection by both parasites showed annual and spatial variability. C. elongatus showed a higher prevalence in 1992 compared to the following years, whereas the prevalence of H. aduncum increased from 1992 to 2001.We observed a relation between parasite distribution and parameters such as latitude and water depth. Adult digeneans (Lecithaster gibbosus and Derogenes varicus) and larval cestodes were also found with lower infection rates. Since changes of infection levels coincided with increasing North Sea water temperature in the studied period, it is hypothesized that temperature may affect parasite population levels. However, it is likely that other environmental factors may contribute to the observed variations. Absence of infection intensities higher than one nematode per fish in small larvae and post-larvae suggests that host survival may be affected by a high infection pressure. The relatively high levels of infection in the younger stages of cod, and the annual/spatial variability of these infections should be considered in the understanding of the early life dynamics of the species.

Improving Corrosion Performance of Thermal Sprayed Coatings with a Zn-Mg-Al Alloy

2019 ◽  
Author(s):  
Christiane Schulz ◽  
Frank Goodwin
Keyword(s):  
Sea Water ◽  
Steel Structures ◽  
Deposition Efficiency ◽  
Product Layer ◽  
Al Alloy ◽  
Spray Process ◽  
The North ◽  
Corrosion Reaction ◽  
The North Sea ◽  
Sprayed Coating

<p>Thermal sprayed zinc and aluminum alloy coatings provide corrosion protection to steel structures. A new thermal sprayed coating with 1-2% of each Al and Mg shows up to 3 times the corrosion resistance of the conventional Zn and ZnAl alloy coatings. Arc sprayed Zn-Mg-Al alloy wire and three reference materials, Zn, Zn-15%Al and Al-5%Mg, gave coatings 100 - 150 µm thick, using either compressed air or nitrogen as an atomizing gas. Formation of splats in the arc wire spray process is dependent on wire chemistry, temperature and size of the particle prior to impact on the substrate. Splat appearance can be correlations with deposition efficiency of the different materials. Corrosion testing was carried out using electrochemical polarization in artificial sea water and by long-term exposure for two years on Heligoland Island in the North Sea. Of the investigated Zn-based materials, ZnMgAl forms the most stable corrosion product layer which delays the anodic corrosion reaction. At the same time ZnMgAl provides sacrificial protection of damaged, uncoated areas of up to 5 mm. Although Al-based coatings, like AlMg5, provide cathodic protection to steel, they suffer from pitting corrosion which can lead - when undiscovered - to sudden catastrophic failure of the structure.</p>

The North Sea: an overview

1987 ◽  
Vol 316 (1181) ◽  
pp. 461-485 ◽  
Keyword(s):  
Trace Metals ◽  
Organic Compounds ◽  
North Sea ◽  
Human Activities ◽  
Sea Water ◽  
Sea Floor ◽  
Natural Systems ◽  
The North ◽  
The North Sea ◽  
Trace Constituents

An overview is given of the natural systems of the North Sea: water-circulation, topography and geology of the sea floor, sediment transport, influx of trace constituents (nutrients, trace metals, organic compounds), biological systems and their interrelations. The effects of pollution and other human activities are discussed as well as the difficulties in assessing them where they are obscured by natural changes.

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