GEOPHYSICAL OPERATIONS IN THE NORTH SEA

Geophysics ◽  
1965 ◽  
Vol 30 (4) ◽  
pp. 495-510 ◽  
Author(s):  
Ernest E. Cook
Keyword(s):  
North Sea ◽  
Eastern Coast ◽  
Identification System ◽  
Quality Of Data ◽  
Multiple Reflections ◽  
Low Velocity ◽  
Lateral Velocity ◽  
Gas Field ◽  
The North ◽  
The North Sea

During the last three years the discovery of the world’s second largest natural gas field at Groningen in the Netherlands has touched off in the North Sea one of the greatest competitive offshore geophysical operations in history. Before 1962, only minor amounts of geophysical work had been done there. Severe weather conditions were expected, but seismic operations have not been as much affected by weather as was originally anticipated. However, strong currents, making cable location uncertain, hampered reflection stacking and refraction operations. Location by radio was also a serious problem due to lack of sufficient available frequencies for a lane identification system. Seismic work was carried out safely in areas mapped as mine fields. Few problems with the fishing industry have so far been encountered. As a preliminary, the geophysics of the Groningen area are discussed. A gravity compilation of the North Sea shows that there are three major basins—the Northwest German Zechstein Basin, the British North Sea Basin, and the Norwegian North Sea Basin. The British Basin which contains Tertiary, Cretaceous, Jurassic, Triassic, Permian, Carboniferous, and older sediments shows considerable salt movement with salt domes, walls, and pillows being in evidence to within 30 miles of the eastern coast of England. Some examples of seismic record sections show the quality of data and the kind of structures encountered. Water reverberations were satisfactorily reduced by means of anti‐ringing procedures. Multiple reflections were frequently observed and often interfered with or obscured simple reflections. Refraction studies indicate that two main refractors, the Upper Cretaceous Chalk and the Upper Magnesian Limestone of the Permian, are present over most of the British Basin. Mapping the key basal Permian reflector is made difficult by deterioration of the reflection under areas of salt growth. Stacking sometimes enhances this reflection. Also intrusions of Permian salt into the Mesozoic beds give rise to large and rapid changes in thickness of the overlying low‐velocity Tertiary and high‐velocity Cretaceous chalk sections. A correction system for these large lateral velocity changes is described.

I.—On a Collection of Pleistocene Mammals Dredged off the Eastern Coast

1878 ◽  
Vol 5 (3) ◽  
pp. 97-100
Author(s):  
William Davies
Keyword(s):  
North Sea ◽  
Eastern Coast ◽  
Dogger Bank ◽  
The North ◽  
Close Proximity ◽  
The North Sea ◽  
Fine Collection ◽  
Pleistocene Mammals ◽  
The Many ◽  
Private Collections

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.”

The Leman Field, Blocks 49/26, 49/27, 49/28, 53/1, 53/2, UK North Sea

2003 ◽  
Vol 20 (1) ◽  
pp. 761-770 ◽  
Author(s):  
A. P. Hillier
Keyword(s):  
North Sea ◽  
Gas Field ◽  
Dune Sands ◽  
The North ◽  
The North Sea ◽  
To Come ◽  
The Uk

AbstractDiscovered in 1966 and starting production in 1968, Leman was the second gas field to come into production in the UK sector of the North Sea and is still producing gas today. It is classified as a giant field with an estimated initial gas-in-place of 397 BCM of gas in the aeolian dune sands of the Rotliegend Group. The field extends over five blocks and is being developed by two licence groups with Shell and Amoco (now BP Amoco) being the operators

The Leman Field, Blocks 49/26, 49/27, 49/28, 53/1, 53/2, UK North Sea

1991 ◽  
Vol 14 (1) ◽  
pp. 451-458 ◽  
Author(s):  
A. P. Hillier ◽  
B. P. J. Williams
Keyword(s):  
North Sea ◽  
Old Field ◽  
Gas Field ◽  
Field Development ◽  
Dune Sands ◽  
The North ◽  
The North Sea ◽  
To Come ◽  
The Uk ◽  
Estimated Ultimate Recovery

AbstractDiscovered in 1966 and starting production in 1968, Leman was the second gas field to come into production in the UK sector of the North Sea. It is classified as a giant field with an estimated ultimate recovery of 11 500 BCF of gas in the aeolian dune sands of the Rotliegend Group. The field extends over five blocks and is being developed by two groups with Shell and Amoco being the operators. Despite being such an old field development drilling is still ongoing in the field with the less permeable northwest area currently being developed.

Navigation and Survey Techniques for the Development of North Sea Satellite Hydrocarbon Fields

1993 ◽  
Vol 46 (1) ◽  
pp. 19-32
Author(s):  
Robert Green
Keyword(s):  
North Sea ◽  
Leading Edge ◽  
Gas Field ◽  
Survey Techniques ◽  
The North ◽  
Hydrocarbon Fields ◽  
The North Sea ◽  
Tools And Techniques ◽  
Oil Gas

The North Sea is at the leading edge of offshore hydrocarbon technology due to its hostile environment and deep water. This paper gives an overview of the role of the offshore surveyor in the North Sea by discussing the survey aspects, tools and techniques used in the development of a contemporary oil/gas field. Particular attention is paid to some of the more unusual techniques being developed today.

scholarly journals The impact of shipping emissions on air pollution in the greater North Sea region – Part 1: Current emissions and concentrations

2016 ◽  
Vol 16 (2) ◽  
pp. 739-758 ◽  
Author(s):  
A. Aulinger ◽  
V. Matthias ◽  
M. Zeretzke ◽  
J. Bieser ◽  
M. Quante ◽  
...  
Keyword(s):  
Particulate Matter ◽  
North Sea ◽  
Transport Model ◽  
Identification System ◽  
Scientific Publications ◽  
The North ◽  
Relative Contribution ◽  
The North Sea ◽  
The Impact ◽  
Concentration Levels

Abstract. The North Sea is one of the areas with the highest ship traffic densities worldwide. At any time, about 3000 ships are sailing its waterways. Previous scientific publications have shown that ships contribute significantly to atmospheric concentrations of NOx, particulate matter and ozone. Especially in the case of particulate matter and ozone, this influence can even be seen in regions far away from the main shipping routes. In order to quantify the effects of North Sea shipping on air quality in its bordering states, it is essential to determine the emissions from shipping as accurately as possible. Within Interreg IVb project Clean North Sea Shipping (CNSS), a bottom-up approach was developed and used to thoroughly compile such an emission inventory for 2011 that served as the base year for the current emission situation. The innovative aspect of this approach was to use load-dependent functions to calculate emissions from the ships' current activities instead of averaged emission factors for the entire range of the engine loads. These functions were applied to ship activities that were derived from hourly records of Automatic Identification System signals together with a database containing the engine characteristics of the vessels that traveled the North Sea in 2011. The emission model yielded ship emissions among others of NOx and SO2 at high temporal and spatial resolution that were subsequently used in a chemistry transport model in order to simulate the impact of the emissions on pollutant concentration levels. The total emissions of nitrogen reached 540 Gg and those of sulfur oxides 123 Gg within the North Sea – including the adjacent western part of the Baltic Sea until 5° W. This was about twice as much of those of a medium-sized industrialized European state like the Netherlands. The relative contribution of ships to, for example, NO2 concentration levels ashore close to the sea can reach up to 25 % in summer and 15 % in winter. Some hundred kilometers away from the sea, the contribution was about 6 % in summer and 4 % in winter. The relative contribution of the secondary pollutant NO3− was found to reach 20 % in summer and 6 % in winter even far from the shore.

scholarly journals Maritime Vessel Classification to Monitor Fisheries with SAR: Demonstration in the North Sea

2019 ◽  
Vol 11 (3) ◽  
pp. 353 ◽  
Author(s):  
Boris Snapir ◽  
Toby Waine ◽  
Lauren Biermann
Keyword(s):  
North Sea ◽  
Automatic Identification ◽  
Identification System ◽  
Fishing Vessel ◽  
Fishing Activity ◽  
The North ◽  
Fishing Vessels ◽  
Monitoring Strategies ◽  
The North Sea ◽  
Sar Imagery

Integration of methods based on satellite remote sensing into current maritime monitoring strategies could help tackle the problem of global overfishing. Operational software is now available to perform vessel detection on satellite imagery, but research on vessel classification has mainly focused on bulk carriers, container ships, and oil tankers, using high-resolution commercial Synthetic Aperture Radar (SAR) imagery. Here, we present a method based on Random Forest (RF) to distinguish fishing and non-fishing vessels, and apply it to an area in the North Sea. The RF classifier takes as input the vessel’s length, longitude, and latitude, its distance to the nearest shore, and the time of the measurement (am or pm). The classifier is trained and tested on data from the Automatic Identification System (AIS). The overall classification accuracy is 91%, but the precision for the fishing class is only 58% because of specific regions in the study area where activities of fishing and non-fishing vessels overlap. We then apply the classifier to a collection of vessel detections obtained by applying the Search for Unidentified Maritime Objects (SUMO) vessel detector to the 2017 Sentinel-1 SAR images of the North Sea. The trend in our monthly fishing-vessel count agrees with data from Global Fishing Watch on fishing-vessel presence. These initial results suggest that our approach could help monitor intensification or reduction of fishing activity, which is critical in the context of the global overfishing problem.

Tidal Currents of the North Sea

1899 ◽  
Vol 22 ◽  
pp. 478-481
Author(s):  
Alexander Buchan
Keyword(s):  
North Sea ◽  
Tidal Flow ◽  
High Water ◽  
Eastern Coast ◽  
The South ◽  
Orkney Islands ◽  
The North ◽  
Deep Channel ◽  
Moray Firth ◽  
The North Sea

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.

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