2001 Strategic Environmental Assessment SEA2 Technical report - Pockmarks in the UK sector of the North Sea

This report is a contribution to Strategic Environmental Assessment SEA2 conducted by the Department of Trade and Industry (now Department of Energy and Climate Change) and it reviews the distribution and character of pockmarks - shallow seabed depressions - which are common in the area of the North Sea to the north-east of Scotland known as the Fladen Ground. Pockmarks are believed to be produced by the escape of fluids (gas or water, but generally gas in the North Sea) from the seafloor and are found in areas where the seabed sediments are soft, silty clays. Processes of pockmark formation, their geometry, age and distribution, and the sources of gas in the underlying geological strata are discussed. While the great majority of pockmarks are inactive at the present time, a few are observed to be actively seeping gas.



In order to provide a stronger basis upon which the significance of pockmarks within mature oil and gas provinces of the North Sea might be assessed, the Department of Trade and Industry commissioned the acquisition of new data directed towards increasing the scientific understanding of sandbanks and pockmarks as part of the SEA2 process. The survey vessel Kommandor Jack was chartered in April 2001 and, among other operations, conducted high-resolution geophysical surveys of pockmarks in the Fladen Ground. Preliminary results from that operation are included in this report.

Simple

Date (Publication)
2001-08-01
Citation identifier
British Geological Survey / BGS_SEA_7
Point of contact
Organisation name Individual name Electronic mail address Role

British Geological Survey (BGS)

Paul Henni

offshoredata@bgs.ac.uk

Custodian

Department for Energy and Climate Change (DECC)

enquiries@decc.gsi.gov.uk

Originator
Maintenance and update frequency
Not planned
Resource format
Name Version

Documents
Keywords

SeaDataNet Parameter Discovery Vocabulary

GEMET - INSPIRE themes, version 1.0

  • Geology

SeaVoX Vertical Co-ordinate Coverages
Use limitation

The SEAs data were produced as part of the UK Department of Energy and Climate Change's Offshore Energy Strategic Environmental Assessment programme; Crown Copyright, all rights reserved. The DECC SEA must be acknowledged in any maps or publications that make use of the data. All the data files are freely available to the public. The Strategic Environmental Assessment (SEA) data portal provides free access to available data and reports which have been produced through the SEA process. The site is run and managed by BGS on behalf of the Department of Energy and Climate Change (DECC). Many files can be downloaded directly from this website. Those that are too large to download can be ordered via the website for postal delivery from BGS. BGS (NERC) has been contracted by DECC to publish SEA datasets on its behalf. All intellectual property rights (including , without limitation, copyrights, database rights and all other rights which subsist or may at any time in the future subsist in the Dataset(s)) in the Dataset(s) ('Intellectual Property Rights') are owned by DECC (formerly the Department of Trade and Industry, and the Department for Business, Enterprise and Regulatory Reform). BGS has been authorised by DECC to use SEA datasets for all purposes but on a 'not-for-profit basis'. BGS has been authorised by DECC to pass on SEA datasets to third parties so that they can use them for all purposes but on a 'not-for-profit' basis.

Access constraints
Intellectual property rights
Distance
5  m
Language
English
Topic category
  • Environment
  • Geoscientific information
  • Oceans
Title

SeaVoX salt and fresh water body gazetteer
Date (Revision)
2006-01-01
Code
North Sea
N
S
E
W
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Begin date
2001-04-20
End date
2001-05-05
Supplemental Information

http://www.offshore-sea.org.uk/site/index.php

Reference system identifier
OGP / urn:ogc:def:crs:EPSG::4326
Distribution format
    OnLine resource
    Protocol Linkage Name
    http://www.bgs.ac.uk/data/sea/home.html

    Strategic Environmental Assessment (SEA) data portal
    Hierarchy level
    Dataset
    Statement

    In April 2001 the survey vessel Kommandor Jack among other operations, conducted high-resolution geophysical surveys of pockmarks in the Fladen Ground as part of the UK Department of Energy and Climate Change's Offshore Energy Strategic Environmental Assessment programme. Geophysical surveying was undertaken using the following equipment: Swath Bathymetry: Simrad EM1002; Side scan sonar: Geoacoustics 159; Sub-bottom profiling: Datasonics Chirp profiler; Positioning: DGPS. This report was prepared by Dr Alan Judd (University of Sunderland) in 2001. Data from offshore site survey reports (made available by the British Geological Survey with permission of the relevant oil companies), as well as published and publicly available material were also used to compile the report.

    Metadata

    File identifier
    aba64100-c0fe-4de3-e044-0003ba6f30bd XML
    Metadata language
    English
    Hierarchy level
    Dataset
    Date stamp
    2011-08-30
    Metadata standard name

    MEDIN Discovery Metadata Standard
    Metadata standard version

    Version 2.3.5
    Metadata author
    Organisation name Individual name Electronic mail address Role

    British Geological Survey (BGS)

    Mary Mowat

    offshoredata@bgs.ac.uk

    		Point of contact
     
     

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    Keywords



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