An assessment of the potential environmental impact of large-scale sand-dredging for the building of artificial islands in the North Sea

The possible presence of very large petroleum and natural gas reserves in the area beneath the North Sea is currently the subject of intense investigation. If confirmed, as seems likely in at least some localities, this occurrence will raise legal problems of considerable interest and complexity. For the North Sea is not merely an oilfield covered by water: for centuries it has been one of the world's major fishery regions and the avenue to and from the world's busiest seaports. Thus all three of the present principal uses of the sea—fishing, navigation, and the exploitation of submarine resources—promise to meet for the first time on a large scale in an area where all are of major importance. The process of reconciling the various interests at stake will provide the first thoroughgoing test of the adequacy and acceptability of the general principles laid down in the 1958 Geneva Convention on the Continental Shelf and should add greatly to the practice and precedents available in this developing branch of the law. In the present article an attempt is made to review some of the geographical and economic considerations involved in the North Sea situation, to note some of the technical and legal developments that have already taken place, and to consider these elements in the light of the various interests and legal principles concerned.

Download Full-text

Inferring the location and scale of mixing between habitat areas of lesser sandeel through information from the fishery

ICES Journal of Marine Science ◽

10.1093/icesjms/fsq154 ◽

2010 ◽

Vol 68 (1) ◽

pp. 43-51 ◽

Cited By ~ 31

Author(s):

Henrik Jensen ◽

Anna Rindorf ◽

Peter J. Wright ◽

Henrik Mosegaard

Keyword(s):

North Sea ◽

Large Scale ◽

Pelagic Fish ◽

Fishing Ground ◽

Marine Science ◽

Foraging Habitat ◽

Small Pelagic Fish ◽

The North ◽

The North Sea

Abstract Jensen, H., Rindorf, A., Wright, P. J., and Mosegaard, H. 2011. Inferring the location and scale of mixing between habitat areas of lesser sandeel through information from the fishery. – ICES Journal of Marine Science, 68: 43–51. Sandeels are small pelagic fish that play an important role in the diet of a range of natural predators. Because of their limited capture by traditional survey gear, little is known about their large-scale distribution or the degree of mixing between habitat areas. Detailed information collected directly from the fishery was used to map fishing grounds, which were then assumed to reflect the foraging habitat of the species. Length distributions from individual hauls were used to assess differences in the distributions as a function of distance between samples. Sandeel foraging habitat covered some 5% of the total area of the North Sea. Mixing between neighbouring fishing grounds was too low to eliminate differences in length distributions at distances between grounds down to 5 km. Within fishing grounds, mixing was sufficient to eliminate differences in length distributions at scales <28 km but insufficient at greater distances. The lack of mixing between grounds may result in large differences in sandeel abundance among adjacent fishing grounds. Further, notable abundance at one end of an extensive fishing ground is not necessarily indicative of similar abundance at its other end.

Download Full-text

Large-scale assessment of masking potential by underwater ship noise the North Sea

The Journal of the Acoustical Society of America ◽

10.1121/10.0007693 ◽

2021 ◽

Vol 150 (4) ◽

pp. A80-A81

Author(s):

Jakob Tougaard ◽

Thomas Folegot ◽

Christ de Jong ◽

Emily T. Griffiths ◽

Alexander M. von Benda-Beckmann ◽

...

Keyword(s):

North Sea ◽

Large Scale ◽

Large Scale Assessment ◽

The North ◽

Scale Assessment ◽

The North Sea

Download Full-text

Extending Production Life of Mature Fields in the North Sea with Multilateral Technology

10.2118/205874-ms ◽

2021 ◽

Author(s):

Matthew Kelsey ◽

Magnus Raaholt ◽

Olav Einervoll ◽

Rustem Nafikov ◽

Stian Amble

Keyword(s):

Environmental Impact ◽

North Sea ◽

Construction Costs ◽

The North ◽

Economic Production ◽

Successful Case ◽

Isolation Methods ◽

Cumulative Production ◽

The North Sea

Abstract Multilateral technology has for nearly three decades extended the production life of fields in the North Sea by delivering a higher recovery factor supported by the cumulative production of the multiple laterals. Additionally, operators continue to look at methods to reduce the environmental impact of drilling and intervention. Taking advantage of the latest multilateral technology can turn otherwise unviable reservoirs into economically sound targets by achieving a longer field life while minimizing construction costs, risk, and environmental impact. This paper will focus on mature fields in the region that have used multilateral applications for wells that were reaching the end of their life and have been extended to further economic production. This paper discusses challenges faced to provide a multilateral solution for drilling new lateral legs in existing wells where there is a lack of available slots to drill new wells. Additionally, discussion will cover completion designs that tie new laterals into existing production casing. The case study will include discussion of workover operations, isolation methods, and lateral creation systems. The paper focuses on the challenges, solutions, and successful case study of a retrofit multilateral well constructed in the North Sea which extended production life in a mature field by using innovative multilateral re-entry methods. The paper also provides insight as to methodology for continually improving reliability of multilateral installations to maximize efficiencies.

Download Full-text

Day-ahead Market Modelling of Large-scale Highly-renewable Multi-energy Systems: Analysis of the North Sea Region Towards 2050

10.20944/preprints202011.0300.v1 ◽

2020 ◽

Author(s):

Juan Gea Bermúdez ◽

Kaushik Das ◽

Hardi Koduvere ◽

Matti Juhani Koivisto

Keyword(s):

North Sea ◽

Large Scale ◽

Unit Commitment ◽

District Heating ◽

Energy Systems ◽

Energy System ◽

Computational Time ◽

Integer Variables ◽

The North ◽

The North Sea

This paper proposes a mathematical model to simulate Day-ahead markets of large-scale multi-energy systems with high share of renewable energy. Furthermore, it analyses the importance of including unit commitment when performing such analysis. The results of the case study, which is performed for the North Sea region, show the influence of massive renewable penetration in the energy sector and increasing electrification of the district heating sector towards 2050, and how this impacts the role of other energy sources such as thermal and hydro. The penetration of wind and solar is likely to challenge the need for balancing in the system as well as the profitability of thermal units. The degree of influence of the unit commitment approach is found to be dependent on the configuration of the energy system. Overall, including unit commitment constraints with integer variables leads to more realistic behaviour of the units, at the cost of increasing considerably the computational time. Relaxing integer variables reduces significantly the computational time, without highly compromising the accuracy of the results. The proposed model, together with the insights from the study case, can be specially useful for system operators for optimal operational planning.

Download Full-text

Large-scale siliciclastic input during the Paleocene-Eocene Thermal Maximum in the North Sea Basin

10.5194/egusphere-egu21-3731 ◽

2021 ◽

Author(s):

Simin Jin ◽

David Kemp ◽

David Jolley ◽

Manuel Vieira ◽

Chunju Huang

Keyword(s):

Carbon Isotope ◽

North Sea ◽

Climate Warming ◽

Large Scale ◽

Time Lag ◽

Sediment Supply ◽

Deep Time ◽

The North ◽

Thermal Maximum ◽

The North Sea

The Paleocene-Eocene Thermal Maximum (PETM, ~56 Ma) was the most marked climate warming event of the Cenozoic, and a potentially useful deep time analogue for understanding environmental responses to anthropogenic carbon emissions and associated warming. The response of sedimentary systems to the large-scale climate changes of the PETM are, however, still uncertain. Here, we present an extremely thick (~140 m) record of the PETM in cores from a well in the North Sea, offshore UK. In this well, a thick Paleocene-Eocene interval is developed owing to uplift of the East Shetland Platform in the late Paleocene. Carbon isotope data through this well, coupled with detailed sedimentological analysis, show that the PETM interval is contemporaneous with >200 sandstone turbidites layers. Mud deposition without turbidites dominated sedimentation below and above the PETM. These observations support previous work from other localities highlighting how climate warming during the PETM likely drove substantial changes in hydrological cycling, erosion and sediment supply. Spectral analysis of turbidite recurrence in the PETM interval suggests that the abundance of turbidites was modulated in part by ~21 kyr astronomical precession climate cycles, further emphasizing a potential climatic control on turbidite sedimentation. In detail, we note a kiloyear-scale time lag between onset of the PETM carbon isotope excursion and the appearance of turbidites in the succession, highlighting a delay between PETM carbon release and warming and the basin-wide response in sediment supply.

Download Full-text

THE BRAER SPILL: OIL FATE GOVERNED BY DISPERSION

International Oil Spill Conference Proceedings ◽

10.7901/2169-3358-1995-1-955 ◽

1995 ◽

Vol 1995 (1) ◽

pp. 955-956 ◽

Cited By ~ 5

Author(s):

T. Lunel

Keyword(s):

Environmental Impact ◽

North Sea ◽

Experimental Work ◽

Oil Spills ◽

Critical Role ◽

Dispersion Process ◽

The North ◽

The North Sea ◽

The Impact ◽

Oil Type

ABSTRACT The fate of 86,000 metric tons (t) of Gullfaks crude oil at the Braer incident was governed by the process of natural dispersion. The overall impact of the spill was minimal in time and extent indicating that dispersing oil spilled at sea can reduce the impact of oil spills. Experimental work in the North Sea has shown that the characteristics of the oil played a critical role in promoting the dispersion process. The Braer incident provides support for the use of dispersants to reduce the environmental impact of a spill in cases where the oil type is less amenable to natural dispersion.

Download Full-text

Wind wake effects of large offshore wind farms, an underrated impact on the marine ecosystem?

10.5194/egusphere-egu2020-12932 ◽

2020 ◽

Author(s):

Corinna Schrum ◽

Naveed Akhtar ◽

Nils Christiansen ◽

Jeff Carpenter ◽

Ute Daewel ◽

...

Keyword(s):

Boundary Layer ◽

North Sea ◽

Large Scale ◽

Spatial Scales ◽

Wind Farms ◽

Offshore Wind ◽

Offshore Wind Farms ◽

The North ◽

The North Sea ◽

Ocean Hydrodynamics

The North Sea is a world-wide hot-spot in offshore wind energy production and installed capacity is rapidly increasing. Current and potential future developments raise concerns about the implications for the environment and ecosystem. Offshore wind farms change the physical environment across scales in various ways, which have the potential to modify biogeochemical fluxes and ecosystem structure. The foundations of wind farms cause oceanic wakes and sediment fluxes into the water column. Oceanic wakes have spatial scales of about O(1km) and structure local ecosystems within and in the vicinity of wind farms. Spatially larger effects can be expected from wind deficits and atmospheric boundary layer turbulence arising from wind farms. Wind disturbances extend often over muliple tenths of kilometer and are detectable as large scale wind wakes. Moreover, boundary layer disturbances have the potential to change the local weather conditions and foster e.g. local cloud development. The atmospheric changes in turn changes ocean circulation and turbulence on the same large spatial scales and modulate ocean nutrient fluxes. The latter directly influences biological productivity and food web structure. These cascading effects from atmosphere to ocean hydrodynamics, biogeochemistry and foodwebs are likely underrated while assessing potential and risks of offshore wind.We present latest evidence for local to regional environmental impacts, with a focus on wind wakes and discuss results from observations, remote sensing and modelling.&#160; Using a suite of coupled atmosphere, ocean hydrodynamic and biogeochemistry models, we quantify the impact of large-scale offshore wind farms in the North Sea. The local and regional meteorological effects are studied using the regional climate model COSMO-CLM and the coupled ocean hydrodynamics-ecosystem model ECOSMO is used to study the consequent effects on ocean hydrodynamics and ocean productivity. Both models operate at a horizontal resolution of 2km.

Download Full-text