Tidal Currents of the North Sea

1899 ◽  
Vol 22 ◽  
pp. 478-481
Author(s):  
Alexander Buchan

In the article “Tides” in the Encyclopœdia Britannica, Professor George Darwin, quoting Sir George B. Airy, remarks that the tides of the North Sea present a very remarkable peculiarity. Along the eastern coast of England as far as the mouth of the Thames, the tide-wave, coming from the Atlantic round the Orkney Islands, flows towards the south. Thus, on a certain day, it is high water in the Moray Firth at 11 a.m., at Berwick at 2 p.m., at Flamborough Head at 5 p.m., and so on to the entrance to the Thames. Thus, on the day supposed, it will be high water off the Thames at 11 p.m., the tide having travelled in twelve hours from the Moray Firth.It is further stated that the North Sea is considerably deeper on the English side than on the German side; so much so, that the tide-wave coming from the north runs into a deep bay of deep water, bounded on the west side by the Scottish and English coasts as far as Newcastle, and on the east side by the great Dogger Bank. As far as the latitude of Hull, the English side is still the deep one; and though a species of channel through the shoal there allows an opening to the east, yet immediately on the south of it is the Wells Bank, which again contracts the deep channel to the English side.It is not stated here that the deeper water of the North Sea close to the Scottish and English coasts determines the course of the southward tidal flow to be close to these coasts; but for that course taken, no other cause is suggested.

Clay Minerals ◽  
1990 ◽  
Vol 25 (4) ◽  
pp. 519-541 ◽  
Author(s):  
M. J. Pearson

AbstractClay mineral abundances in Mesozoic and Tertiary argillaceous strata from 15 exploration wells in the Inner and Outer Moray Firth, Viking Graben and East Shetland Basins of the northern North Sea have been determined in <0·2 µm fractions of cuttings samples. The clay assemblages of more deeply-buried samples cannot be unambiguously related to sedimentary input because of the diagenetic overprint which may account for much of the chlorite and related interstratified minerals. Other sediments, discussed on a regional basis and related to the geological history of the basins, are interpreted in terms of clay mineral provenance and control by climate, tectonic and volcanic activity. The distribution of illite-smectite can often be related to volcanic activity both in the Forties area during the M. Jurassic, and on the NE Atlantic continental margin during the U. Cretaceous-Early Tertiary which affected the North Sea more widely and left a prominent record in the Viking Graben and East Shetland Basin. Kaolinite associated with lignite-bearing sediments in the Outer Moray Firth Basin was probably derived by alteration of volcanic material in lagoonal or deltaic environments. Some U. Jurassic and L. Cretaceous sediments of the Inner Moray Basin are rich in illite-smectite, the origin of which is not clear.


Author(s):  
F. S. Russell

1. Details are given of the types of hooks lost in tunny in the North Sea in the summer of 1933.2. Data are given on the measurements made on thirty-two large migrating fish caught in the North Sea in August and September, 1933.3. In certain body proportions the tunny measured differ from those in the G4 Group (200 to 260 cm. in length) given by Heldt for fish from Tunis and by Frade for fish from Algarve on the south coast of Portugal, while in some characters they resemble the Tunis fish and in others the Algarve fish, but all the North Sea fish were between 232 and 271 cm. in length.4. It was found that there was a tendency for fish with short second dorsal fins to have short first dorsal, anal, and caudal fins, and for those with long second dorsals to have these other three fins long.5. Measurements were made to supply data on the condition of the fish.


1878 ◽  
Vol 5 (3) ◽  
pp. 97-100
Author(s):  
William Davies

Of the many private collections of vertebrate fossils found on or off the coast of the Eastern counties, none surpass in palæontological and also in geological interest the fine collection made with much zeal and care by Mr. J. J. Owles, of Yarmouth, inasmuch as the larger portion of the specimens are exclusively the remains of Postglacial Mammals, and were brought up in the fishermen’s dredge, either from, or in close proximity to the well-known Dogger Bank, thus proving conclusively the existence of submerged Pleistocene or Postglacial land lying off the Eastern coast in the North Sea. Prof. Boyd Dawkins is the only author, as far as I am at present aware, who has made any reference to this really valuable series of remains, and then only incidentally in his memoir, “On the Distribution of Postglacial Mammals.”


1992 ◽  
Vol 12 (2-3) ◽  
pp. 213-233 ◽  
Author(s):  
G.K. Verboom ◽  
J.G. de Ronde ◽  
R.P. van Dijk

1866 ◽  
Vol 3 (26) ◽  
pp. 348-354 ◽  
Author(s):  
Searles V. Wood

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.


The North Sea sedimentary basin has developed on the northwestern margin of the European tectonic plate and contains an almost continuous record of epeirogenic marine and deltaic sedimentation from Carboniferous to Recent times. The subsidence required to accommodate the pile of sediment deposited, which in places exceeds 12 km, has been brought about at various times and in various places by differing geodynamical processes. As a result the types of sedimentary rocks deposited vary widely both in time and space, but the nature of the mechanism is reflected in the sedimentary type deposited. The following broad generalizations can be made. The late Carboniferous was a period of deltaic sedimentation during which eustatic changes in sea level or local variations in subsidence rates are reflected in the typical Coal Measures swamp deposits. Late Carboniferous - early Permian times saw the silting up of this basin, and in an arid climate aeolian sands were deposited grading laterally to sabkha shales and evaporites. The Permian culminated in a series of widespread marine incursions during which repetitive evaporites were deposited. Triassic times were marked by a period of major rifting and the deposition of thick sequences of continental elastics in the north, while widespread marine sedimentation persisted in southern areas. Jurassic times saw the re-establishment of marine to deltaic deposition in a series of basins possibly controlled in their distribution by the Triassic fault systems. Late Jurassic deposits were laid down in a sea whose bathymetry reflected the structure of the underlying horsts and grabens inherited from Triassic times, and towards the close of the Jurassic the bottom waters at least of this sea become increasingly stagnant. Sands deposited during the late Jurassic were deposited as near-shore marine bars, beach sands, and proximal and distal submarine fans. Triassic to early Cretaceous deposition was concentrated in the areas now occupied by the main grabens of the North Sea, i.e. the Viking, Central and Moray - Witch Ground grabens. Subsequent deposition in late Cretaceous to Tertiary times took place in a more widely subsiding area, resulting in progressive onlap onto the surrounding basin margins. Deposition within this broadly subsiding and relatively unfaulted basin is characterized by chalky limestones in southern areas, giving way laterally to shales and minor sands to the north. During early Tertiary times a large delta was formed in the area beneath the present Moray Firth, and from this delta a supply of sand was fed into submarine fans to the northeast and southeast of the delta front. Late Tertiary deposition is largely represented by a monotonous sequence of marine shales.


Author(s):  
J.W. Horwood ◽  
R.S. Millner

Large catches of sole (Solea solea) were made in early 1996 from the south-western North Sea. Sole suffer physiological damage in waters below 3–4 C. In February 1996 cold water of 3–4 C unusually extended from the Continental coast onto the Dogger Bank. It is likely that the increased catches were due to the consequential distribution and behaviour of the sole, making them more susceptible to capture.Exceptionally large catches of mature sole (Solea solea (L.)) were made in February 1996 by Lowestoft fishermen from the south-western North Sea. Surprisingly this was not welcome. The UK allocation of the North Sea sole is -4 % of the EU Total Allowable Catch (TAC), and fishermen are restricted nationally, and by the fishing companies, to a tightly managed ration. The Lowestoft Journal (8 March 1996) reported the suspension of a local fishing skipper for not throwing back 5000 kg of sole caught in the Silver Pits. We will show that the abnormal catches were due to exceptionally cold waters.Sole in the North Sea are at the northern extremity of their range, with sole seldom living in waters below 5°C (Horwood, 1993). In fact, North Sea sole were successfully introduced into Lake Quarun, Egypt, where they lived in temperatures in excess of 30°C (El-Zarka, 1965). Young sole migrate from their shallow inshore nursery grounds, such as the Waddensea, as winter approaches (Creutzberg & Fonds, 1971).


1982 ◽  
Vol 8 ◽  
pp. 9-26
Author(s):  
Claus Andersen ◽  
Jens Christian Olsen ◽  
Olaf Michelsen ◽  
Erik Nygaard

The Central Graben is a broad, complex trough with a long history of differential subsidence. It was probably initiated in the Permian and was controlled by major rifting during the Mesozoic. To the south in the Dutch sector the trough is divided into two parts. From here it passes northwards and divides the southern North Sea Basin into the Anglo-Dutch Basin and the Northwest German Basin. It also separates the Mid North Sea High from the Ringkøbing-Fyn High. These highs form broad, east-west trending, relative stable ridges. The further continuation of the Central Graben is to the northwest, towards the centre of the North Sea, where it passes into the Viking Graben and the Moray Firth Basin at about 58° N. Where the Central Graben divides the two major highs, there is an elongate central narrow horst, the Dogger High, which is the southernmost of a row of mid-Graben highs. Both sides of the Graben are clearly defined by normal rotational faults that were intermittently active from Triassic to Early Cretaceous times.


1919 ◽  
Vol 6 (6) ◽  
pp. 273-274 ◽  
Author(s):  
W. I. Saxton ◽  
A. T. Hopwood

The general behaviour of the Scandinavian ice-sheet which spread over the North Sea at the climax of the Glacial period is fairly well known. Numerous erratics show that it reached the coast of Yorkshire and the eastern counties of England. Farther north no erratics have been found, but Dr. Jamieson and others have shown that it approached the coast of Aberdeen. Dr. Croll and Drs. Peach and Horne have shown that it forced the Scotch ice flowing eastward from the Moray Firth to turn in a northerly and north-westerly direction across the northern part of Caithness and over the Orkneys. They concluded that ice from the Christiania district must have passed a few miles to the north of the Orkneys. This is well shown in the chart attached to their paper and also in Professor James Geikie's map. The occurrence of a few Scandinavian erratics in the Orkneys would confirm these deductions. The only erratic recorded from Orkney which may be of Scandinavian origin is the Saville boulder described by Professor Heddle, Drs. Peach and Horne, and Dr. J. S. Flett.


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