5e7f738b-0cfc-4f0e-a7fa-cd35417a3d8d eng series Centrica Energy Renewable Investments (CERI) GIS and Data Manager Millstream East, First Floor Windsor SL4 5GD United Kingdom CERI@centrica.com pointOfContact 2014-01-09 MEDIN Discovery metadata standard 2.3.7 urn:ogc:def:crs:EPSG::32630 2011, Reynolds International, Zone 9 Celtic Array, Seismic Data Processing 2012-09-20 publication 2011-12-12 creation CERIR32012REYNOLDSSEISMIC http://www.centrica.com Reynolds International Ltd (RIL) has been appointed by Dr Sophia Fannon-Howell of Centrica Renewable Energy Ltd (CREL; the Client) to provide geophysical processing of single-channel marine seismic data acquired for the Irish Sea Zone. As defined by the Client, the seismic dataset comprises 1003 lines, of which 537 are in IEEE format and 466 are in IBM format. A significant number of the IEEE lines have data saved to two channels. The raw data quality ranges from ‘good’ to ‘not interpretable’. Some lines do not contain navigation information in their headers, with these navigation data being supplied in separate navigation files. A bathymetry data archive consisting of x,y,z text files and PosMV data was also supplied. Initial investigation of the dataset, prior to the work in this report being commissioned, revealed that the two-channel IEEE data contains one ‘strong’ channel containing primary seismic data, and one ‘weak’ channel with near-zero amplitudes. The main aims of the processing were to: 1. Split the dual-channel data to single-channel data files containing the ‘strong’ channel only. 2. Improve the interpretability of the data through seismic processing. 3. Edit the SEG Y files such that they contain correct navigation data. Secondary aims were to: 1. Convert the x,y,z bathymetry data to grid format files readable by the KINGDOM seismic interpretation software. 2. Create auxiliary navigation files to ensure no loss of resolution in SEG Y file navigation data when processed SEG Y files are loaded into KINGDOM. Within this series, the processing report and two addendums are provided, as well as the seismic and bathymetric datasets. Centrica Energy Renewable Investments (CERI) GIS and Data Manager Millstream East, First Floor Windsor SL4 5GD United Kingdom CERI@centrica.com custodian Reynolds International Limited Reynolds International Limited, Unit 17, Mold Business Park, Wrexham Road Mold Flintshire CH17 1XP United Kingdom info@reynolds-international.co.uk originator unknown GXF Layer Package SEG Y CSV Unknown Excel (.xls) Unknown Seismic refraction SeaDataNet Parameter Discovery Vocabulary 2019-07-26 revision 113 Seismic reflection SeaDataNet Parameter Discovery Vocabulary 2019-07-26 revision 113 Bathymetry and Elevation SeaDataNet Parameter Discovery Vocabulary 2019-07-26 revision 113 Consenting The Crown Estate Renewable Energy Development Phases 2012-05-15 revision 1 Zone search area The Crown Estate Renewable Energy Development Areas 2012-05-15 revision 1 Marine Environmental Data and Information Network Marine Environmental Data and Information Network otherRestrictions otherRestrictions Distribution by Centrica Energy Renewable Investments Limited (CERI) Ltd on a case by case basis Distribution by Centrica Energy Renewable Investments Limited (CERI) Ltd on a case by case basis 3700 eng elevation environment geoscientificInformation SeaDataNet vertical extent keywords 2010-01-01 revision atmosphere SeaDataNet vertical extent keywords 2010-01-01 revision water_column Charting Progress 2 Sea Areas 2009-06-18 creation Irish Sea ICES Rectangles 2009-05-01 creation 36E5 International Hydrographic Bureau, Limits of Oceans and Seas 1954-01-01 creation Irish Sea and St. George's Channel -5.0537 -3.6694 53.4913 53.9755 2011-03-01 2011-12-12 series Seismic Processing Summary: 1. Files were renamed, where necessary, in order to reduce file name length to avoid file path length limitations during processing 2., Every SEG Y file was loaded into the file splitting software and inspected by eye to identify (a) if the data were single- or dual-channel and (b) the ‘strong’ data channel. The strong data channel was extracted from all dual-channel data files and saved with the file name suffix ‘_0’ if channel 0 contained the strong data, or ‘_1’ if channel 1 contained the strong data. 3. As part of the file splitting process, each output file was converted to 32-bit standard-format SEG-Y. 4. Files matching the following criteria were deleted:  Less than ten traces.  No navigation in the header and no external navigation file.  The line is a duplicate of another line. 5. Each split line was inspected visually to classify it by data quality, where the primary concern was the degree of processing required rather than interpretability 6. During quality categorisation, several lines were noted to contain reverse polarity data. To maintain consistency throughout the data volume, the trace amplitudes in the reverse polarity lines were reversed. 7. The first two traces of each line were deleted in order to prevent potential interpolation of interface picks across large gaps during later interpretation. 8. Gain to compensate for spherical divergence was applied prior to bandpass filtering. 9. Bandpass filters applied where required 10. A trace amplitude equalisation filter was applied to all lines in order to improve reflector continuity both along and between lines. Batheymetry Processing Summary: 1.The 2x2 m text grid files were concatenated for each area, then converted to points. The points were then converted to ESRI grids (without applying interpolation). 2. The area grids areas for A, B, C, D, E and F only were then combined to form a single project area bathymetry grid, again taking the mean of overlapping grid cells. All area grids were then converted to KINGDOM-compatible uncompressed *.gxf files 3. The 1x1 m text grid files were processed up to ESRI grids. 4. As part of RIL’s data quality checks, the bathymetry data were converted to time using an arbitrary value of 1,490 m/s for the average speed of sound in the water column. Further information is available in report: R3-D-EN-078-0000-000000-017 https://www.marinedataexchange.co.uk/details/2655/summary A link to the web service or dataset. https://www.marinedataexchange.co.uk A link to the general host site.