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    This dataset includes two cruises of data collected to investigate Arctic hydrate dissociation as a consequence of climate change and to determine vulnerable methane reservoir and gas escape mechanisms. Work during both JR269A and JR269B was focused on two separate geographical areas. The first of these was west of Prins Karls Forland, in water depths of between 150 and 1200 m. At its landward end, this survey area crosses a region at water depths up to 400 m where a dense concentration of methane escape bubble plumes occur. The second survey area straddles the summit of the Vestnesa Ridge, in water depths of 1180 to 1400 m, and is also the site of methane escape bubble plumes within the water column and of fluid escape chimneys and pockmarks previously imaged at and beneath the sea bed. This area lies approximately 100 km west of the mouth of Kongsfjorden. Data collection took place between August 2011 and July 2012. The research expedition used a deep-towed, very high resolution seismic system to image the small-scale structures that convey gas to the seabed and to detect the presence of gas in the sediments. This was done in conjunction with an electromagnetic exploration system that uses a deep-towed transmitter and receivers on the seabed to derive the variations in electrical resistivity in the sediments beneath the seabed. The observations carried out on the two cruises included; underway, meteorological observations and echo sounder data, multichannel seismic reflection profiling data, wide angle seismic survey data, and ocean bottom seismometer (OBS) data, ocean bottom electro-magnetometer data and controlled source electromagnetic surveys (CSEM). The overall objectives of the project were to determine the spatial distribution of gas and hydrate accumulations beneath the sea bed; to investigate and understand gas transport and escape mechanisms, their spatial distribution, and the controls on these; and to quantify gas and hydrate saturation values in situ within the pore spaces of the shallow sediment reservoirs. The research is focused on specific areas where significant accumulations of methane hydrate and active methane venting through the sea floor were observed and documented during the earlier JR211 cruise in 2008. This is a NERC funded project hosted by University of Southampton. The data held at BODC include multichannel seismic reflection, TOPAS sub-bottom profiler and 2D seismic reflection data in SEG-Y format. No further data are expected.

  • 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.

  • This report is a contribution to the Strategic Environmental Assessment (SEA5) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change). This report reviews published and newly-acquired seabed geological data in an area of 78,000 square kilometres extending from the coast to more than 200 m water depth to the east of the British Isles. While it can be argued that the modern environment is a product of past environmental conditions, the basis for the review is also that our understanding of the modern environment can be significantly improved if new techniques, data and ideas are applied to a revision of the existing research knowledge. The purpose of the review is to place the characteristics of the seabed features that were surveyed by the DTI in 2003, and the processes forming them, into an improved understanding of their historical, local and regional context. In the summer of 2003 the DTI carried out new surveys in order to collect environmental information in 6 project areas in SEA5 and 2 project areas in SEA4. The survey data included multi-beam bathymetry, sidescan sonar, seismic reflection profiles, sea-floor photographs and samples.

  • 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.

  • 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.

  • 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 surficial sediments in the SEA4 area and the sedimentary processes that are active in the area at the present day. The report focuses on the deeper water areas from the outer continental shelf to the floor of the Norwegian Basin in the northernmost part of SEA4. The report is based on sidescan sonar images, multibeam bathymetry, sub-bottom profiles, seabed photographs and sediment samples. The Holocene and late glacial events and processes that contributed to the present day seafloor morphology and sediment distribution are reviewed, as is the present day oceanographic regime. It is concluded that the present day sedimentary environment, seaward of the continental shelf edge at about 200 m water depth, is dominated by low sediment input and deposition rates, and by reworking of surficial sediments by bottom currents. The large scale seabed morphology was shaped mainly during the last glacial, when high sediment input resulted in glacigenic debris fan formation.

  • This report is a contribution to the Strategic Environmental Assessment (SEA5) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change). This report reviews published and newly-acquired seabed geological data in an area of 78,000 square kilometres extending from the coast to more than 200 m water depth to the east of the British Isles. While it can be argued that the modern environment is a product of past environmental conditions, the basis for the review is also that our understanding of the modern environment can be significantly improved if new techniques, data and ideas are applied to a revision of the existing research knowledge. The purpose of the review is to place the characteristics of the seabed features that were surveyed by the DTI in 2003, and the processes forming them, into an improved understanding of their historical, local and regional context. In this way a strong element of the review is to include the results from exploration and discovery. The survey data included multibeam, sidescan sonar, seismic-reflection profiles, sea floor photographs and samples.

  • 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.