This report is a contribution to the Strategic Environmental Assessment (SEA4) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change). The report describes the field of mud diapirs in the northern part of the SEA4 area, known as the Pilot Whale Diapirs, which were mapped during a multibeam survey carried out in 2002. A diapir is a fold or dome caused by more plastic rocks at depth, such as salt or mud, intruding overlying denser rocks, generally driven by their own buoyancy. Sometimes a diapir breaks through to the seafloor. The diapir field extends over an area some 60 km across, creating a very variable seabed terrain. The largest diapirs have produced elevations at the seafloor of more than 120m. The largest diapirs in the group are thought to have intruded to the seafloor from 500m or more beneath it. The evidence suggests that the diapirism was initiated between 5 and 1 million years ago, but it does not appear to be continuing at the present time.

As part of as part of the Department of Trade and Industry's (now Department of Energy and Climate Change) Strategic Environmental Assessment (SEA2) a geophysical survey was carried out in three different quarters of the North Sea: Norfolk Coast (Area 1), Dogger Bank (Area 2) and Fladen Ground (Area 3) from Kommandor Jack SEA2 Survey Leg 1, 2001. Multibeam, sidescan sonar and chirp seismic data were collected. The survey was carried to identify potential offshore Special Areas of Conservation (SACs). It was necessary to acquire data on specific features identified in the EU Habitats Directive, such as sandbanks and pockmarks, some of which might subsequently be defined as SACs. The survey was carried out in two legs. Leg one included the geophysical surveys in three different quarters of the North Sea as well as the charting which was used to guide the sampling and photographic work on the second leg. The following data are available - 25 files of processed multibeam data. Screenshots of backscatter processing are also available. Side-scan mosaics. Images are available from 15 boxes. Processed seismic data. Cruise report

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.

As part of the Department of Trade and Industry's (now Department of Energy and Climate Change) Strategic Environmental Assessment (SEA6) a seabed sampling, video and geophysical survey was undertaken in the central Irish Sea with specific focus given to areas of Liverpool Bay and Tremadog Bay. The survey objectives were to conduct a strategic environmental study of locations where features of interest had been previously identified by organisations such as the Countryside Council for Wales and the School of Ocean Sciences. Survey operations were focused on the following features: Possible methane-derived carbonate reefs in Cardigan Bay; Gassy Sediments in Tremadog Bay, Biogenic Reefs - Horse mussel beds. 36 video files are available. 186 photographs are available. 52 samples were collected using a Day Grab. A cruise report is available Processed data mosaics are available

This report is a contribution to the Strategic Environmental Assessment (SEA4) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change). The report is a summary of published data and interpretations describes the surficial seabed geology and geological processes affecting the continental shelf part of the SEA4 area, lying in water depths of less than 200 m. Roughly half of the SEA4 area lies in these water depths. The report reviews the seabed geomorphology, near-bottom currents, types of rock outcrop, variations in the texture of the unconsolidated sediments, the variety and distributions of seabed bedforms and selected aspects of the inorganic geochemistry of the sediments. Variations in the seabed geology have a major influence on the organisms that live on the bottom, thus are important to understanding the modern seabed habitat. The modern seabed environment now largely reflects the effects of reworking by near-bottom currents on the topography and the sediments that originated during the glaciations.

This report is a contribution to the Strategic Environmental Assessment (SEA6) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change). Methane-derived authigenic carbonate (MDAC) is formed as a consequence of the anaerobic oxidation of methane by consortia of bacteria. MDAC develops as a rock-like concretion when a carbonate precipitate cements normal seabed sediment; the carbon of this carbonate is derived from methane. It occurs as crusts or slabs at the seabed, or as exposed lumps. The occurrence of MDAC is evidence of methane seepage, although the seepage is not necessarily going on at the present time. Large quantities of MDAC indicate that methane seepage has occurred over a prolonged period of time. 'Submarine structures formed by leaking gas' have been identified by the European Commission's Habitats Directive as habitats worthy of protection. The distribution of MDAC in UK waters is poorly known. This report summarises the available information relevant to MDAC in the SEA6 area, including data acquired by surveys specifically conducted in support of this SEA in 2004. Carbon isotope data for samples recovered in 2004 have confirmed that the cemented hard grounds from two of the areas studied, Texel 11 and Holden's Reef, are composed of MDAC.

1999 SEA1 (White Zone) - TOBI surveys of the Wyville-Thomson Ridge and the eastern slope of the Faeroe-Shetland Channel carried out during the Department of Trade and Industry's (now Department of Energy and Climate Change) Strategic Environmental Assessment SEA1. This preliminary report describes the data collection and interpretation carried out by Southampton Oceanography Centre in the summer of 1999. The work was carried out in two survey legs, Leg A was a regional side-scan sonar survey, whilst leg B was a seafloor survey of targets selected from the results of leg 1. This preliminary report is presented in 4 sections: Section 1 - Cruise report for Leg A; Section 2 - Cruise report for Leg B; Section 3 - Regional environmental interpretation from side-scan sonar and camera data; Section 4 - Initial environmental assessment. Raw data and the survey report are available.

This report is a contribution to the Strategic Environmental Assessment (SEA4) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change). The SEA4 area includes the most northerly part of the UK continental shelf, north of the Shetland Islands between the international boundaries with Norway and the Faroe Islands, and the area to the west of Shetland and the Orkney Islands. Starting with scenarios of possible exploration and development activity in the area provided by the Department of Trade and Industry, this study provides forecasts of oil and gas production, expenditure, employment and tax revenues. The impacts of future oil and gas developments in the SEA4 area on the local economies of Shetland and Orkney will be small in comparison to what has happened in the past. The main impact will be to postpone or to slow down the decline in UK oil production. Nevertheless, production from fields in the area could make significant contributions to overall UKCS production, employment and tax revenues, as well as extending the lives of facilities such as the Sullom Voe and Flotta terminals. It could help to retain employment and population in the area.

This report is a contribution to the Strategic Environmental Assessment (SEA6) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change). This report provides an overview of all the relevant data concerning methane-derived authigenic carbonate (MDAC) and other features associated with shallow gas and seabed fluid flow in the Irish sector of the western Irish Sea. The report complements the MDAC report produced for the SEA6 area by Dr A. G. Judd.