2005 Strategic Environmental Assessment SEA2 Investigation of the origin of shallow gas in Outer Moray Firth open blocks 15/20c and 15/25d

As part of the Department of Trade and Industry's (now Department of Energy and Climate Change) Strategic Environmental Assessment (SEA2), this report briefly describes the evidence for the origin of shallow gas in Outer Moray Firth open blocks 15/20c and 15/25d. Sea floor pockmarks are known to occur within these blocks, and they indicate the seepage of gas from shallow levels into the local water column. An environmental concern is that any industry activity in these blocks must not plumb into any component of the system that is sustaining the gas seepages at sea bed. The study area covers two part-blocks within the eastern part of the Witch Ground Graben within the UK Central North Sea. This study follows on from the DTI 2001 SEA research on pockmarks.
dataset
Strategic Environmental Assessment (SEA) data portal - The Strategic Environmental Assessment (SEA) data portal provides free access to available data and reports which have been produced through the UK Department of Energy and Climate Change 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.
British Geological Survey : BGS_SEA_16
English
Environment
Geoscientific information
Oceans
SeaDataNet Parameter Discovery Vocabulary: GEMET - INSPIRE themes, version 1.0:
Geology
SeaVoX Vertical Co-ordinate Coverages:
Free:
-1.90, 52.80, 3.30, 61.80
publication: 2005-02-01
2005-01-01 - 2005-01-01
British Geological Survey (BGS)
Paul Henni
Murchison House, West Mains Road, Edinburgh, EH9 3LA, UK
tel: +44 (0)131 667 1000
email: offshoredata@bgs.ac.uk
Role: custodian
Department for Energy and Climate Change (DECC)
Admiralty Way, London, SW1A 2HD, UK
tel: +44 0300 060 4000
email: enquiries@decc.gsi.gov.uk
Role: originator

Data Quality

This report was compiled by the British Geological Survey as part of the UK Department of Energy and Climate Change's Offshore Energy Strategic Environmental Assessment programme. The study comprised three main tasks: A desk study based on publications in the literature and unpublished reports to determine whether or not there is already a consensus on the derivation of the gas seepages in blocks 15/20c and 15/25d; A quick interpretation of available BGS shallow seismic data and commercial site survey data to determine the extent of the gas in the shallow subsurface.; Quick interpretation of appropriate horizons on the PGS MegaSurvey for indications of gas seepages from deeper levels. Use of seismic attribute analysis to map the locations of Tertiary channels that might be acting as migration conduits into the area. Investigate for gas chimneys, faults extending to shallow levels, amplitude anomalies, evidence for sediment remobilisation and any other evidence for upward gas migration into the shallow subsurface.
Minimal Distance: 5 http://standards.iso.org/ittf/PubliclyAvailableStandards/ISO_19139_Schemas/resources/uom/gmxUom.xml#m

Constraints

Metadata about metadata

aba64100-c106-4de3-e044-0003ba6f30bd
British Geological Survey (BGS)
Mary Mowat
tel: +44 (0)131 667 1000
email: offshoredata@bgs.ac.uk
Role: point of contact
2011-08-30

Coupled Resource