The propagation of tide and surge in an estuary

1955 ◽  
Vol 231 (1184) ◽  
pp. 8-24 ◽  
Keyword(s):  
Shallow Water ◽  
Theoretical Investigation ◽  
High Water ◽  
Meteorological Conditions ◽  
Order Of Approximation ◽  
Progressive Wave ◽  
Thames Estuary ◽  
Small Depth ◽  
Open Sea ◽  
Progressive Waves

This paper is a theoretical investigation of the distribution, along an estuary, of a combination of tide and surge which have been generated in the open sea. The following results relate to the same sequence of meteorological conditions over the sea. For a single progressive wave, the height of a surge whose maximum occurs near to the time of tidal high water is less than that of a surge whose maximum occurs near to the tune of tidal low water, and it decreases as the range of tide increases. To the order of approximation followed in the paper, these differences are due to friction and increase with distance from the sea. For a standing oscillation, the following results relate to the head of the estuary. When the primary surge rises to its maximum more rapidly than it falls from it, and when this maximum occurs near to the time of tidal high water, the effect of shallow water is to make the surge increase as the range of tide increases, and the effect of friction is to make the surge decrease as the range of tide increases. On applying the formulae of the paper relating to progressive waves to the Thames Estuary, it appears that, owing to the small depth of water at mean level, the details only hold for a few miles from the sea. But the tendencies enumerated should hold all the way to London.

The effect of friction on a progressive wave of tide and surge in an estuary

1955 ◽  
Vol 233 (1194) ◽  
pp. 407-418 ◽  
Keyword(s):  
High Water ◽  
Meteorological Conditions ◽  
Theoretical Distribution ◽  
Progressive Wave ◽  
Inertia Term ◽  
Open Sea ◽  
Non Linear ◽  
Basic Equations

This is a second paper on the theoretical distribution, along an estuary, of a combination of tide and surge which have been generated in the open sea. It differs from the first paper in that, in the basic equations, the non-linear inertia term is neglected, and only one phase of the wave is considered at a time. Also, the formulae are now valid for any height of tide or surge at the mouth of the estuary and for any distance from the sea. For the same sequence of meteorological conditions over the sea and when the height of surge at the mouth of the estuary is greater than a certain fraction of the range of tide there, the surge up the estuary is less at the time of high water than it is at the time of low water, and it decreases as the range of tide increases. This is a wide extension of the range of validity of one of the results of the first paper.

4. The tide in shelf seas

2019 ◽  
pp. 50-64
Author(s):  
David George Bowers ◽  
Emyr Martyn Roberts
Keyword(s):  
Shallow Water ◽  
Earth Rotation ◽  
Standing Waves ◽  
High Water ◽  
The South ◽  
Continental Shelves ◽  
Shelf Seas ◽  
Shelf Sea ◽  
Progressive Waves ◽  
Shallow Seas

‘The tide in shelf seas’ describes progressive waves, standing waves, and what happens when a shelf sea is in resonance, using the example of the Gulf of St Vincent off the south Australian coast. It also considers the effect of Earth rotation and tides in shallow water, where the rare feature is double high water or double low water. The great ocean basins are bordered by shallow seas lying on the continental shelves. Shelf seas are generally less than 200 metres deep and vary in width from almost nothing to hundreds of kilometres. It is in these shallow seas and the rivers that flow into them that the most spectacular tides are found.

scholarly journals I. On the laws of the tides on the coasts of Ireland, as inferred from an extensive series of observations made in connection with the ordnance survey of Ireland

1845 ◽  
Vol 135 ◽  
pp. 1-124 ◽  
Keyword(s):  
Accurate Determination ◽  
High Water ◽  
Eastern Coast ◽  
Western Coast ◽  
Ordnance Survey ◽  
The North ◽  
Small Depth ◽  
Open Sea ◽  
The Difference ◽  
Hydrostatic Level

In the spring of 1842 I was informed by Colonel Colby, R. E., Director of the Trigonometrical Survey, that in the operations of the Survey of Ireland it had become necessary to adopt a line of reference for the elevations ascertained in the running of various lines of level through the country; and that it was his intention to institute a series of observations of the height of the water in different states of the tide, in order to refer the levels to the mean height of the sea, or to its height at some definite phase of the tide. Colonel Colby stated also that he was desirous that the observa­tions should be made subservient to improvements in the theory of the tides, and requested my assistance in sketching a plan of observation which would be most likely to contribute to that end. In reply, I made the following suggestions:—That great care should be taken in the accurate determination of time at every station, and that for this purpose the non­commissioned officer of the Royal Sappers and Miners who had the care of the observations at each station, should be entrusted with a pocket chronometer, and that an officer should, at least twice during the series of observations, visit every station, carrying, for comparison, an itinerant chronometer whose error on Greenwich time was accurately known from astronomical observations. That stations should be chosen on the eastern as well as on the western coast, in order to determine the difference of level, if any, between an open sea and a partially inclosed sea. That on the north-eastern coast, stations should be selected at smaller intermediate distances than at other parts of the coast, with the purpose of removing, if possible, the doubt which appears to exist as to the progress of the semidiurnal tide-wave through the North Channel. That, where practicable, several stations should be selected on each of the large rivers or estuaries, in order to ascertain the nature of the modification which the tide-wave undergoes in passing up a contracted channel of comparatively small depth. That the series of observations should be so arranged, that, at every station, one complete tide (from high water to high water, or from low water to low water) should be completely observed on every day, its observations being made at small equidistant intervals. That supplementary observations, applying only to the neighbourhood of the low water or high water omitted in the observations of the complete tide, should also be made, for the development of the principal facts of diurnal tide. Finally, that the zeros of the tide-gauges should be connected with the principal lines of level, so that every observation should be referred to the same hydrostatic level.

Oscillations of tide and surge in an estuary of finite length

1957 ◽  
Vol 2 (4) ◽  
pp. 371-382 ◽  
Author(s):  
J. Proudman
Keyword(s):  
Shallow Water ◽  
Cross Section ◽  
Finite Length ◽  
High Water ◽  
Meteorological Conditions ◽  
The Other ◽  
Infinite Length ◽  
First Order ◽  
Long Wave ◽  
Uniform Cross Section

This paper concerns a narrow basin of uniform cross-section open to the sea at one end and closed at the other. An incident long wave of prescribed general form is supposed to enter from the sea and to represent the combination of tide and surge as generated in the sea. The solution of the linear terms of the equations of continuity and motion gives the reflection of this wave at the head of the estuary. This paper gives the next approximation when the non-linear terms are retained, the second-order motion being made determinate by the condition that, at the mouth, it reduces to a progression towards the sea.The chief results relate to the surface elevation at the head of the estuary. When the first order elevation there increases steadily to a maximum, the effect of the ‘shallow water terms’ is to make high water higher and earlier, while the effect of the ‘frictional term’ is to make high water lower and later. For a short estuary, the interaction of the tide on a surge, due to a given sequence of meteorological conditions over the sea, is to make it higher when its maximum occurs at the time of tidal high water than when its maximum occurs at the time of tidal low water. This is directly opposite to the corresponding result when the estuary is of infinite length.

scholarly journals Shallow water waves in a rotating rectangular basin

2000 ◽  
Vol 24 (10) ◽  
pp. 649-661 ◽  
Author(s):  
Mohamed Atef Helal
Keyword(s):  
Shallow Water ◽  
Water Waves ◽  
Equations Of Motion ◽  
System Of Nonlinear Equations ◽  
System Of Equations ◽  
Order Of Approximation ◽  
Shallow Water Waves ◽  
Nonlinear System Of Equations ◽  
Rectangular Basin ◽  
Shallow Water Approximation

This paper is mainly concerned with the motion of an incompressible fluid in a slowly rotating rectangular basin. The equations of motion of such a problem with its boundary conditions are reduced to a system of nonlinear equations, which is to be solved by applying the shallow water approximation theory. Each unknown of the problem is expanded asymptotically in terms of the small parameterϵwhich generally depends on some intrinsic quantities of the problem of study. For each order of approximation, the nonlinear system of equations is presented successively. It is worthy to note that such a study has useful applications in the oceanography.

scholarly journals Seasonal variability of hydrodynamics in the Vistula Estuary in 1994

2007 ◽  
Vol 36 (4) ◽  
Author(s):  
Małgorzata Robakiewicz
Keyword(s):  
Wind Direction ◽  
Water Body ◽  
Seasonal Variability ◽  
River Mouth ◽  
Meteorological Conditions ◽  
Field Observations ◽  
Mixing Processes ◽  
Local Conditions ◽  
Open Sea ◽  
Region Model

Seasonal variability of hydrodynamics in the Vistula Estuary in 1994The Vistula Estuary is a coastal water body boasting free connection with the open sea, where mixing processes of marine and fluvial waters are maintained by local conditions. Based on results from a hydrodynamic model, applied to represent conditions in the year 1994, and using salinity as a tracer, it was found that fluvial water has a tendency to spread westward from the river mouth. This is in contradiction with the dominant wind direction in the region. Model results confirmed field observations of specific hydrological and meteorological conditions required to transport fluvial water northward, towards the Hel Peninsula.

scholarly journals HIGH-WATER PROBLEMS ON THE DANISH NORTH SEA COAST

2011 ◽  
Vol 1 (6) ◽  
pp. 6
Author(s):  
C. Ringe-Jorgensen
Keyword(s):  
North Sea ◽  
High Water ◽  
Meteorological Conditions ◽  
Dutch Coast ◽  
Water Problems ◽  
Sea Coast ◽  
North Sea Coast ◽  
Made In ◽  
Frequency Curves

With reference to the use of high-water frequency curves, which have been suggested by Wemelsfelder as an aid to fix the maximum flooding level, an attempt will be made in the following to estimate how far certain special geographical and meteorological conditions may be expected to influence the shape of the frequency curves for different localities. The investigation concerns a particular point on the Danish North Sea coast compared with the Dutch coast, but its principles may possibly be of interest in a wider sense.

The Biology of Laminaria Hyperborea. VIII. Growth on Cleared Areas

1976 ◽  
Vol 56 (2) ◽  
pp. 267-290 ◽  
Author(s):  
Joanna M. Kain ◽  
N. S. Jones
Keyword(s):  
Growth Rate ◽  
Shallow Water ◽  
Personal Communication ◽  
Fast Growth ◽  
Depth Range ◽  
Laminaria Hyperborea ◽  
Isle Of Man ◽  
Rocky Subtidal ◽  
Small Depth

INTRODUCTIONStudies of established populations of Laminaria hyperborea (Gunn.) Fosl. have indicated that there is often less change of growth rate with depth than might be expected to result from the decrease in irradiance (Kain, 1967; Lüming, 1969; Jupp & Drew, 1974). This has been attributed to self-limitation by the canopy of Laminaria fronds (Lüning, 1969; Kain et al. 1976). The removal of this canopy can result in fast growth in shallow water (Kitching, 1941; Svendsen, 1972) and a marked differential in growth rate over a small depth range (Svendsen, personal communication). A series of rocky subtidal areas at two depths off the Isle of Man was cleared of vegetation at various times (Kain, 1975a). This provided an opportunity to make growth measurements on individuals of known age in the absence of a canopy formed by older plants.

scholarly journals A New Small Drifter for Shallow Water Basins: Application to the Study of Surface Currents in the Muggia Bay (Italy)

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Carmelo Nasello ◽  
Vincenzo Armenio
Keyword(s):  
Free Surface ◽  
Shallow Water ◽  
Coriolis Force ◽  
Surface Current ◽  
Meteorological Conditions ◽  
Water Current ◽  
Surface Currents ◽  
Water Basin ◽  
Surface Circulation ◽  
The City

A new small drifter prototype for measuring current immediately below the free surface in a water basin is proposed in this paper. The drifter dimensions make it useful for shallow water applications. The drifter transmits its GPS location via GSM phone network. The drifter was used to study the trajectory of the surface current in the Muggia bay, the latter containing the industrial harbor of the city of Trieste (Italy). The analysis has been carried out under a wide variety of wind conditions. As regards the behavior of the drifter, the analysis has shown that it is well suited to detect the water current since its motion is marginally affected by the wind. The study has allowed detecting the main features of the surface circulation within the Muggia bay under different meteorological conditions. Also, the study has shown that the trajectory of the surface current within the bay is weakly affected by the Coriolis force.

scholarly journals Boat-towed radio-magnetotelluric and controlled source audio-magnetotelluric study to resolve fracture zones at Äspö Hard Rock Laboratory site, Sweden

2019 ◽  
Vol 218 (2) ◽  
pp. 1008-1031 ◽  
Author(s):  
Shunguo Wang ◽  
Mehrdad Bastani ◽  
Steven Constable ◽  
Thomas Kalscheuer ◽  
Alireza Malehmir
Keyword(s):  
Shallow Water ◽  
Penetration Depth ◽  
Large Scale ◽  
Hard Rock ◽  
High Water ◽  
Fracture Zones ◽  
Geological Structures ◽  
Near Surface ◽  
Controlled Source ◽  
Rock Laboratory

SUMMARY Boat-towed radio-magnetotelluric (RMT) measurements using signals between 14 and 250 kHz have attracted increasing attention in the near-surface applications for shallow water and archipelago areas. A few large-scale underground infrastructure projects, such as the Stockholm bypass in Sweden, are planned to pass underneath such water zones. However, in cases with high water salinity, RMT signals have a penetration depth of a few metres and do not reach the geological structures of interest in the underlying sediments and bedrock. To overcome this problem, controlled source signals at lower frequencies of 1.25 to 12.5 kHz can be utilized to improve the penetration depth and to enhance the resolution for modelling deeper underwater structures. Joint utilization of boat-towed RMT and controlled source audio-magnetotellurics (CSAMT) was tested for the first time at the Äspö Hard Rock Laboratory (HRL) site in south-eastern Sweden to demonstrate acquisition efficiency and improved resolution to model fracture zones along a 600-m long profile. Pronounced galvanic distortion effects observed in 1-D inversion models of the CSAMT data as well as the predominantly 2-D geological structures at this site motivated usage of 2-D inversion. Two standard academic inversion codes, EMILIA and MARE2DEM, were used to invert the RMT and CSAMT data. EMILIA, an object-oriented Gauss–Newton inversion code with modules for 2-D finite difference and 1-D semi-analytical solutions, was used to invert the RMT and CSAMT data separately and jointly under the plane-wave approximation for 2-D models. MARE2DEM, a Gauss–Newton inversion code for controlled source electromagnetic 2.5-D finite element solution, was modified to allow for inversions of RMT and CSAMT data accounting for source effects. Results of EMILIA and MARE2DEM reveal the previously known fracture zones in the models. The 2-D joint inversions of RMT and CSAMT data carried out with EMILIA and MARE2DEM show clear improvement compared with 2-D single inversions, especially in imaging uncertain fracture zones analysed in a previous study. Our results show that boat-towed RMT and CSAMT data acquisition systems can be utilized for detailed 2-D or 3-D surveys to characterize near-surface structures underneath shallow water areas. Potential future applications may include geo-engineering, geohazard investigations and mineral exploration.

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