Alternate title

D273

Date (Publication)

2003-08-28

Citation identifier

British Geological Survey / BGS_CMD_REF300

Point of contact

Organisation name	Individual name	Electronic mail address	Role
British Geological Survey (BGS)		enquiries@bgs.ac.uk	Custodian
British Geological Survey (BGS)		offshoredata@bgs.ac.uk	Originator

Maintenance and update frequency

Not planned

Keywords

• NDGO0001

GEMET - INSPIRE themes, version 1.0

• Geology

SeaVoX Vertical Co-ordinate Coverages (L131)

• soil and sediment
• crust

SeaDataNet Parameter Discovery Vocabulary (P021)

• Gravity
• Bathymetry and Elevation
• Magnetics
• Two-dimensional seismic reflection

Access constraints

Other restrictions

Access constraints

No restrictions, a copyright acknowledgement is required and permission from any third party for the release of the data has been obtained. Inclusion of any third party data will determine the copyright acknowledgement that needs to be made.

Use constraints

Other restrictions

Other constraints

The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council [NERC]. No part of this work may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the prior permission of the copyright holder, via the BGS Intellectual Property Rights Manager. Use by customers of information provided by the BGS, is at the customer's own risk. In view of the disparate sources of information at BGS's disposal, including such material donated to BGS, that BGS accepts in good faith as being accurate, the Natural Environment Research Council (NERC) gives no warranty, expressed or implied, as to the quality or accuracy of the information supplied, or to the information's suitability for any use. NERC/BGS accepts no liability whatever in respect of loss, damage, injury or other occurence however caused.

Use limitation

unrestricted use, copyright acknowledgement - Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced British Geological Survey materials "Contains British Geological Survey materials ©UKRI [year]"

Spatial representation type

Grid

Distance

5  urn:ogc:def:uom:EPSG::9001

Language

English

Topic category

• Geoscientific information

Geographic identifier

Geikie

BGS Gazetteer 2025-05-08 revision

Geographic identifier

Kennedy

BGS Gazetteer 2025-05-08 revision

Geographic identifier

Rosemary Bank

BGS Gazetteer 2025-05-08 revision

Geographic identifier

Darwin

BGS Gazetteer 2025-05-08 revision

Geographic identifier

Lousy Bank

BGS Gazetteer 2025-05-08 revision

Geographic identifier

Bill Bailey's Bank

BGS Gazetteer 2025-05-08 revision

Geographic identifier

North Rockall Basin

BGS Gazetteer 2025-05-08 revision

Geographic identifier

North Hatton

BGS Gazetteer 2025-05-08 revision

Geographic identifier

Scottish Continental Shelf

Charting Progress 2: Regional Sea Boundaries 2009-06-18 creation

Geographic identifier

Atlantic North-West Approaches, Rockall Trough and Faeroe/Shetland Channel

Charting Progress 2: Regional Sea Boundaries 2009-06-18 creation

Geographic identifier

NORTHEAST ATLANTIC OCEAN (40W)

The SeaVoX Salt and Fresh Water Body Gazetteer: Sub-Ocean Category 1954-01-01 creation

Begin date

2003-08-11

End date

2003-08-28

Reference system identifier

OGP / urn:ogc:def:crs:EPSG::4326

www.epsg.org 2005 revision

Distribution format

Distributor contact

Organisation name	Individual name	Electronic mail address	Role
British Geological Survey (BGS)		enquiries@bgs.ac.uk	Distributor

OnLine resource

Protocol	Linkage	Name
HTTP	http://mapapps2.bgs.ac.uk/geoindex_offshore/home.html?cruise=2003/1	BGS Offshore Geoindex

Hierarchy level

Dataset

Statement

Geophysical equipment types used included: Airgun/Sleeve Gun, Echo Sounder, Gravimeter, Magnetometer, Pinger and Sparker. The survey was undertaken by British Geological Survey. AIRGUN SYSTEM - Source: An array of 5 x 40 cu.in. Bolt 600B airguns with waveshape kits and time break solenoids. Routinely, up to four guns were fired simultaneously, keeping the fifth gun as a ready spare. The number of guns used was varied with water depth, with a minimum of two being used in the shallower areas. The firing rate varied from 6 – 8 seconds depending on water depth. Gun synchronisation was achieved by monitoring the time break solenoids and manually adjusting as required. This introduced a short time delay into the system of approximately 50 msec and thus the sea-bed return time was not an absolute measurement of depth. Hydrophone: Two channel Geomechanique summed to give a single channel 30m active length. The summing amplifier used was a newly developed BGS unit, which also incorporated low pass and anti-alias filters. Recording: CODA DA200 four channel digital recording and processing system. The data was recorded on Exabyte tape in CODA format with a sampling interval of 0.2 msec, record length of 4 seconds and bandpass filter of 20-800Hz. The start of recording was delayed in deep water to permit a minimum of 2 seconds (TWTT) of data below the sea bed. The CODA system also received a navigation data string from the navigation processor, and logged position on each shot. On-line processing: CODA system.Processes applied were time varied gain (TVG), time varied filtering (TVF) and trace mixing. Both TVG and TVF were applied from the sea bed, which was tracked automatically. SPARKER SYSTEM - Source: EG&G, nine candle, multi-tip array with 135 tips. High Voltage Power Supply: 2 x Applied Acoustic Engineering CSP3000 capacitor charging units, switchable output up to a maximum of 2.2 KJ. Hydrophone: Teledyne, 10 m, 7 channels with all summed to give a single output. Recording: The same CODA DA200 four channel digital recording and processing system as for the airgun. The data were recorded with a sampling interval of 0.1 msec, record length of 1.5 seconds and a bandpass filter of 103-1730 Hz. SUB- BOTTOM PROFILER - IOS 3.5kHz system: a high resolution, deep water (up to 6000m) swept or ‘chirp’ frequency profiling system transceiver: Raytheon PTR 105B producing 6 kWatts of acoustic power. Recorder: Waverley 3710 Linescan recorder and was selected for a 480 msec sweep. The towfish contained four TR109F Massa transducers wired in a parallel series combination. GRAVITYMETER - LaCoste and Romberg AIR-SEA system. MAGNETOMETER - Direct Reading Barringer M123 marine proton precession magnetometer with 1 gamma sensitivity. VECTOR MAGNETOMETER: A three-component vector magnetometer, supplied by the BGS Geomagnetism Programme. ECHO SOUNDER - Simrad EA500 hydrographic echo sounder with a 9 element tow fish operating at 10 kHz. NAVIGATION - Primary: Trimble GPS 4000DL. Secondary: Ashtech GG-24 (combined GPS + GLONASS). The differential corrections for both of these files are fed from a Sea Star (3000L DGPS set to Eik EMS). it must be assumed that prior to 0000 Day 236, positioning was GPS without differential corrections. The ship’s Ashtec ADU-2 (ships attitude) multihead GPS was logged for the duration of the cruise All position data are referred to the WGS 84 datum. For more detailed information on the acquisition equipment and data collection techniques, operational standards, data processing methods and quality control procedures used on this survey see the Report of Survey/Cruise Report and associated documentation where available. The information available may vary depending on the age of the survey. Data are checked and loaded to the BGS Coastal and Marine data management system following BGS marine data management procedures.

Metadata

File identifier

abc9f747-534e-0f38-e044-0003ba9b0d98 XML

Metadata language

English

Hierarchy level

Dataset

Date stamp

2025-05-08

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)		enquiries@bgs.ac.uk	Point of contact