Coast Of Great Britain Research Articles

An empirical investigation of interaction between storm surge and astronomical tide on the east coast of Great Britain

A measure of non-linear interaction between storm surge and astronomical tide is defined and this is used to make a comparison of interaction at various ports on the east coast of Great Britain using several years of storm surge data. In so far as the variation of interaction along the coast is concerned, the degree of interaction is highly correlated with the range of the tide for ports under the influence of the same amphidromic system; the correlation with surge height is less significant. When the ports are considered individually, however, the main characteristics of surgetide interaction can be determined by an empirical method based on the amplitude and variability of the hypothetical storm surge obtained using a linearised prediction theory. The method is demonstrated for the particular port of Southend, in the Thames Estuary.

CASE HISTORIES OF TWO ESTUARIES

The coast of Great Britain has many interesting examples of the interaction between tidal estuaries of rivers and the littoral drift of the coast. These have been described with historical detail mainly by geographers (ref.l). Two cases coming to the author's firm for action have interest for coastal engineers. For the River Spey m the Moray Firth of Scotland, a famous and vigorous river, unusual works have been undertaken with success. For Dawlish Warren, a sand spit m the Exe Estuary of Devon m South West England, a scheme of works is being prepared which has novelty in regard to British practices.

Immigration of Algæ into Danish Waters

THANKS to the careful studies of the late Prof. Rosenvinge on the vegetation of Algae in Danish waters, particularly in the ‘nineties, we are now able to study the changes since that time in the algal flora. An increase has occurred in this flora, amounting to five species during the past fifty years: the red alga, Trailliella intricata, Batters ; the two green algae, Codium dichotomum (Huds.) Setchell (= C. tomentosum (Huds.) Stackh.) and Codium fragile (Sur.) Hariot (= C. mucronatum J.Ag.) ; and the brown algae, Dictyota dichotoma (Huds.) Lamour. and Colpomenia peregrina Sauv. (= C. sinuosa var. peregrina Sauv.). The first three mentioned were recorded by Rosenvinge1, the last two by Lund2,3. They are forms of a somewhat more southern origin, which have gradually spread towards the north ; but the Danish localities are not their northernmost limits, for they were also met with on the west coast of Norway. They are all known from the coasts of Great Britain.

Oversea Propagation on Wavelengths of 3 and 9 Centimeters

This paper summarizes the results obtained from tests extending from 1943 to 1946 which were made to determine the meteorological factors controlling the propagation of centimeter waves. Oversea paths of 60 and 200 miles off the West Coast of Great Britain were used for the experiments. Continuous records of radio field strengths and frequent measurements of the meteorological conditions along the paths were made. The correlation between the radio results and the various meteorological parameters is studied in the light of current theories of microwave propagation.

Seaweed resources along the shores of Great Britain

Extraction of alginates from brown algae and utilization of them in the manufacture of thread in Great Britain during World War II led to a survey of seaweed resources along the coast of Great Britain which revealed a supply of over 2,000,000 tons of bottomweed and rockweed in those waters, especially around Scotland.

The Eternal Problem of Macedonia

over a quarter of this century, as well as a few decades before the end of the last century, a little bit of useless economic territory, Macedonia, has been the core of most of the problems of the Balkans and of Europe's power politics. New variations of the old problem have cropped up again in 1945, 1946, and 1947. While formerly the problem of Macedonia was only a European problem, today it is a world-wide problem which is of supreme importance to the United States, whose former ideological Maginot Line lay along the coast of Great Britain and Western Europe. In fact, in the spring of 1947, a peace settlement with the prime mover of World War II suddenly was shifted into the background, while trouble in Britain and danger in Greece overshadowed the Moscow Conference and confronted the United States Government with a crisis that Washington officials called exceedingly grave; President Truman, by cancelling a longplanned trip to the Caribbean, and by delivering a formal address to Congress on the subject, emphasized official attitude. Underlying this crisis was the ever-returning problem of Macedonia, within the framework of the decision of London to cut down British aid to Greece to a size that hard-pressed Britain of 1947 can support. United States was invited to move in. Further, in the background, was the drive for control of the Dardanelles and the Eastern Mediterranean and the drive of the pro-Soviet regimes around Greece against the proAmerican-British regime in Athens. Communist bands in Macedonia were creeping across the frontiers from Albania, Yugoslavia, and Bulgaria, and aggravated an uprising that for years to come will threaten to produce an armed if unofficial showdown between the British and Americans on the one hand, and the Russians on the other. The talking stage took place at the turn of 1947, when a commission appointed by the Security Council of the United Nations investigated the cause of the border battles. A prelim-

The Mexican Loggerhead in Europe

THE discovery of Kemp's loggerhead in the Azores is of considerable interest, but we obviously still need much more information before we can do more than guess at the causes underlying the movements of these turtles. Among other things, it is essential to discover whether the species is resident around these western islands, for it is quite possible that the single young one found there is a stray similar to those which reach the British coast. The Azores, like the British Isles, lie within the area to which larval eels are carried from their breeding grounds in the western Atlantic. Is it possible that there may be a correlation between the migration of Leptocephalus and the movements of these turtles? Or is it a coincidence that ‘glass-eels’ (larval stage 5) appear off the Spanish coast in September and October, off Ireland in November, and that turtles are stranded on the south-western coast of Great Britain in November and December?

Fifyt Years' Progress in Marine and General Engineering: Jubilee of the North-East Coast Institution of Engineers and Shipbuilders

OF the various industrial districts around the coasts of Great Britain, none has a greater variety of industries than that known as the ‘North-East Coast’. Here, situated on the banks of the Tyne, the Wear and the Tees are coal-wharves, ship-yards, engine-shops, steel-works and factories by the score. But the outstanding industries are shipbuilding and marine engineering, and ships built or engined at Wallsend, Elswick, Hebburn, Shields, Sunderland or Hartlepool are found all over the world. As compared with the Thames, the Mersey and the Clyde in the early days of steamships, the district occupied a minor position as a shipbuilding centre. About the middle of last century, however, it began to specialise in the building of economical slow cargo ships, and its success in this direction led to developments which perhaps are as remarkable as they were unexpected. In 1850, the depth at low water over the bar at the mouth of the Tyne was only 6 ft. Now the channel of the river is dredged to more than thirty feet, and into the river have been launched such vessels as the Mauretania and H.M.S. Nelson. To-day, ships of many classes and marine engines of every type are constructed in the district.

Coast Erosion and Protection

THIS work, wliicli is the third edition of the late Prof. Matthews's book on coast erosion and protection, consists very largely of a record of the long experience of the author in dealing with these problems. It deals with the erosion and accretion that is taking place around the coasts of Great Britain and with the various typos of sea defences, the merits and defects of each type being discussed in detail. There is some discussion of the action of sea water on concrete, while the effect of harbour projections on the travel of sand and shingle is briefly referred to. The present edition also contains a chapter on recent practice, by Dr. Brysson Cunningham, and an appendix giving the conclusions on coast protection drawn up for the International Association of Navigation Engineers in 1931.

Letters to the Editor

RECENT letters by Dr. Kemp and Mr. F. S. Russell1 and Mr. A. C. Stephen2 have directed attention to the occurrence of Atlantic organisms on the coasts of Great Britain and Ireland. It may be of interest to add another example to the list. While the Fishery Cruiser Muirchu of the Department of Lands and Fisheries was engaged in taking physical observations off the south-west coast of Ireland, fifty miles south-south-west of Fastnet Light, on August 9, 1932, considerable numbers of a large salp, 3–8 cm. long, were noticed drifting a few feet below the surface and some were captured. These proved to be the sexual stage of Cyclosalpa bakeri, Ritter. Several other specimens occurred in a tow-netting taken on the same station, and also in another taken seventy miles south-south-west of the Fastnet, suggesting that the shoal may have been twenty miles across. Cyclosalpa bakeri appears to be mainly a tropical species and I do not know of any previous record from British or Irish waters.

Ships and Shipping

A VERY excellent little volume and a most handy addition to any shipping office. The naval information makes it also a very useful book to naval officers. One slight improvement would be useful—port-to-port distances round the coast of Great Britain and Europe; for example, London to Plymouth. Ships and Shipping. By Commander R. Dowling. With a preface by Lieut. W. G. Ramsay Fairfax, R.N. Second Edition. Pp. xv + 423. (London: A. Moring, Ltd., 1905.) Price 5s. net.

I.—Oscillations of Level along our South Coast since the Human Period

In the latest number of the Quarterly Journal of the Geological Society there is a description by Mr. D. Pigeon, F.G.S., of recent discoveries in the submerged Forest of Torbay. The paper is highly interesting, and records many facts, valuable alike to the geologist and archæologist. But the inferences he draws from them in opposition to Mr. Pengelly, though not altogether unchallenged in the discussion of his paper, were not contradicted as emphatically as they might have been. As I take interest in, and have observed signs of upheaval and depression along our coast-line, and believe that scarcely any part of the coast is at rest, I beg leave to protest against this latest of several attempts to show, that remains of forests, now beneath the sea-level, originally grew at the levels they now occupy. We know that it is possible that forests might grow at a lower level than the sea until a protecting dam gave way and they became overwhelmed; but I would ask whether there is any example of such growing anywhere round the coasts of Great Britain to-day, and whether there is anything to lead to the belief that there were, at the epochs of these submerged forests, any physical conditions that rendered it more probable that forests might have grown below high-water mark along the coasts, then than now. To admit that there were, would admit a change of some kind, presumably of level, which is what I maintain. My own idea is that the physiography, of the south coast at least, is entirely opposed to the growth of forests behind dykes below the sea-level, and that the only probable explanation of their present position is a subsidence of the area on which they grew. This seems so self-evident that I should hardly have thought any other view could have been supported. The conclusion I take most particular exception to is this: “That a coast which has remained stationary for the last 2000 years should have made such active use of the preceding twelve or twenty centuries for the purposes of oscillation, is rather hard of belief.” In the first place there is no sort of evidence that the coast was stationary for 2000 years, and in the second, were it so, it would not present any reason to my mind why evidence of the occurrence of oscillations in the 2000 years preceding should be rejected.

On the Occurrence of Great Tides since the Commencement of the Geological Epoch

MR. BALL says very truly that the fundamental question is, what traces of great tides ought we to expect to find if those great tides had really existed? Mr. Darwin says, coarse-grained rocks, and different forms of vegetation calculated to resist the action of the accompanying great winds. Mr. Ball, in reply, remarks that high tides in the Avon are accompanied by fine sediment. He thinks with others that the high tides would have produced a vastly greater amount of sediment than is being formed at present. I quite agree with Mr. Ball about the fine sediment, but I am not at all clear that high tides mean great marine denudation. By far the largest portion of the work done by the sea as a denuding agent is due not to the wearing action of currents, or to the pounding of materials on a beach at low water, but to the direct action of the sea on the cliffs. This force is estimated as about a ton per square foot on the average in winter, on the west coast of Great Britain. This undermines the cliff at the sea level, and then the top part falls partly by its own weight, but still more through the effect of the air compressed in the caves and cracks, which by its elasticity spread the blow over a very large surface through the crack and joints of the rock. Now to undermine cliffs with a given force of wind and wave, it seems clear that the maximum effect would be produced where the tides are very small, for there the force is constantly applied at the same spot. With a rise and fall of 100 feet, each portion of the cliff would be subjected to the force of the waves for so short a time that in all probability caves would never be formed at all, and the height of the tide would be an actual protection to the land. As a matter of fact, those places where the tides are highest show, as far as I know, no signs of excessive denudations. I spent two days last year on the Bay of Fundy, where the tides are higher than anywhere in the world, and I was very much struck with the absence of any evidence of great denudation due to the tide. The cliffs at the Joggias are about high-water mark, with a long beach which slopes very gradually. The force of the waves, such as they are, is spent in hammering this beach and grinding it into fine sand and mud; the mud is carried about in suspension by the tide, and the sand is shifted about, but the denuding effect is exceedingly small. The consequence is that the cliffs are pounded by the waves for such a short time each tide that they suffer mainly from atmospheric denudation, the sea doing little more than keeping their base clear, and in many places not even doing that.

XII. On dredgings and deep-sea soundings in the South At­lantic, in a letter to Admiral Richards, C. B., F. R. S. By Prof. Wyville Thomson, LL. D., F. R. S., Director of the civilian staff on board H. M. S. ‘Challenger.'

Dear Admiral Richards,—1 have the pleasure of informing you that, during our voyage from the Cape of Good Hope to Australia, all the necessary observations in matters bearing upon my department have been made most successfully at nineteen principal stations, suitably distributed over the track, and including Marion Island, the neighbour­ hood of the Crozets, Kerguelen Island, and the Heard group. After leaving the Cape several dredgings were taken a little to the southward, at depths from 100 to 150 fathoms. Animal life was very abundant; and the result was remarkable in this respect, that the general character of the fauna was very similar to that of the North Atlantic, many of the species even being identical with those on the coasts of Great Britain and Norway. The first day’s dredging was in 1900 fathoms, 125 miles to the south-westward of Cape Agulhas; it was not very successful.

XIV. On the present amount of westerly magnetic declination [variation of the compass] on the coast of Great Britain, and its annual changes

From the rapid decrease in late years of the amount of Westerly Magnetic Declination over the whole area of the United Kingdom and the adjacent seas, the attention of the Hydrographic Department of the Admiralty has been constantly directed to this interesting physical fact as one specially affecting coast navigation and the accuracy of compass-bearings derived from the current charts. The duties of Her Majesty’s Surveying-vessels engaged on our own shores having within the last few years included districts embracing nearly the whole extent of coastline, the opportunities thus afforded for a careful determination of the magnetic declination at widely spread and favourable localities were, under the direction of Admiral Richards, C. B., F. R. S., the Hydrographer of the Admiralty, taken advantage of, and suitable instruments furnished to the Commanding Officers from the Admiralty Compass Department.

V. On the present amount of westerly magnetic declination [variation of the compass] on the Coasts of Great Britain, and its annual changes

The rapidly accelerating value within the last few years of the annual decrease of the westerly magnetic declination over the whole area of the United Kingdom and the adjacent seas, as observed at the fixed magnetic observatories of Greenwich, Kew, Brussels, Paris, and also at Christiania in Norway, is a subject of importance in practical navigation as affecting the compass-bearings derived from charts and those laid down for the guidance of pilots. The attention of the Hydrographic Department of the Admiralty has been constantly directed to this interesting physical fact; and as the duties of Her Majesty’s surveying-vessels employed on our shores between the years 1866 and 1870 embraced nearly the whole extent of coast-line, advantage was thus taken, undert he orders of Rear-Admiral Richards, C. B., F. R. S., the Hydrographer, to determine, with great attention to accuracy, the magnetic declination at widely spread and favourable localities.

2. On a remarkable Oscillation of the Sea observed at various places on the coasts of Great Britain, in the first week of July 1843

This phenomenon was observed on the 5th July and three following days. It did not occur on all parts of the coasts of Great Britain. In England, it was observed only on the south shores of Cornwall and Devonshire. In Scotland, it was observed on the east coast; and there it was seen at a great many places, between Eyemouth in Berwickshire and the Shetland Islands.It was only on the 5th July that the oscillation occurred on the Cornish and Devonshire coasts. It prevailed on the Scottish coast, however, from the 5th to the 7th July inclusive.The phenomenon consisted of a flux and reflux of the sea, beyond what could be accounted for by ordinary tides, or any wind prevailing at the time. The water suddenly rose up and sunk down from 2 to 5 feet in perpendicular height, producing effects more or less striking, according to the shelving character of the shore.

XXXIX.—On a Remarkable Oscillation of the Sea, observed at various places on the Coasts of Great Britain, in the first week of July 1843

This phenomenon presented a remarkable interference with those laws which govern the ordinary movements of the ocean. It occurred at one place whilst the tide was flowing, at another whilst it was ebbing; in some cases, producing a sudden retrocession of the waters,—and in others, as sudden an impulse of them on the shore.The period during which the sea thus continued to retreat and rise respectively, was generally from ten to fifteen minutes. It then made a momentary halt—after which, it began to flow in the opposite direction, and which it continued to do, for about the same period which characterised its previous movement.In this state of alternate flux and reflux, the sea was at most places observed to continue, for three or four hours together.

XXV. Note on the tides in the port of London

Mr. Stratford has favoured me with a comparison of the predicted times of high water deduced from Mr. Bulpit’s Tables, White’s Ephemeris, and the British Almanac, with the observations at the London Docks. These observations are, unfortunately, so imperfect, that the differences must not be entirely attributed to the errors of the Tables, which, however, seem susceptible of much improvement. I subjoin this comparison; and in order to convey an idea of the confidence which may be placed in the observations, I also subjoin a comparison, by Mr. Deacon, of the observations at the London and St. Katherine’s Docks, which are made according to the same plan, and of which the merit is the same. The differences in the determinations at these two places, which are only about a quarter of a mile distant from each other, may serve to indicate the reliance which can be placed in either. In my paper on the Tides at Brest, I remarked that the retard or the constant λ — λ, is considerably greater as deduced from observation here than at Brest. That this must be the case is also evident from the following very simple à priori considerations.—The highest high water takes place when the moon passes the meridian at a time equal to the retard. The tide is propagated from Brest to London, round Scotland, in about twenty-two hours, that is, supposing the tide which takes place in our river to be principally due to that branch of the tide which descends along the eastern coast of Great Britain, which I believe to be the case. The highest tide therefore is propagated from Brest to London in about twenty-two hours, and the difference in the retard or in the constant λ — λ, will be nearly the moon’s motion in twenty-two hours, or about 11°; I made the difference in the retard from observation 10°. The tide takes about fifteen hours to reach Brest from the Cape of Good Hope; no doubt the retard there is considerably less.

LII. On the tides on the coast of Great Britain

LII. On the tides on the coast of Great Britain