Date (Publication)

2006-08-23

Citation identifier

British Geological Survey / BGS_CMD_REF655

Point of contact

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

• Bathymetry and Elevation
• Two-dimensional seismic reflection
• Side-scan sonar

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 Historic Scotland materials "Contains Historic Scotland materials ©Crown Copyright [year]"

Spatial representation type

Grid

Distance

5  urn:ogc:def:uom:EPSG::9001

Language

English

Topic category

• Geoscientific information

Geographic identifier

Tiree

BGS Gazetteer 2025-06-30 revision

Geographic identifier

Minches & Western Scotland

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

Geographic identifier

INNER SEAS OFF THE WEST COAST OF SCOTLAND

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

Begin date

2006-08-23

End date

2006-08-23

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=WESSEX3B	BGS Offshore Geoindex

Hierarchy level

Dataset

Statement

Geophysical equipment types used included: CHIRP Sub-bottom Profiler, Echo Sounder and Sidescan Sonar. The survey was undertaken by Wessex Archaeology. Throughout the survey all co-ordinates were expressed in WGS84, UTM zone 29N. Single beam bathymetric data were recorded throughout all stages of surveying and was acquired using a Knudsen 320M single beam echo sounder. The echo-sounder transducer was mounted to the survey vessel, and the transducer draught was measured and entered into the echo sounder to obtain depths relative to the sea-surface. A TSS DMS 2.05 motion sensor was rigidly mounted above the transducer to measure the vertical displacement (heave) and attitude (roll/pitch) of the vessel; this data was interfaced with the echo sounder. The accuracy of the draught and velocity offsets were checked at the start of the survey using the bar check method. Sub-bottom profiler data were acquired using a chirp system. The chirp system used was the new EdgeTech 3100P portable sub-bottom profiling system using a SB-126S tow vehicle. The chirp is a high resolution wideband frequency modulated sub-bottom profiler. The system transmits a frequency modulated pulse that is swept over a full spectrum frequency range (in this case 2-12 kHz). The vertical resolution using 2 – 12 kHz frequency is 8cm and in an area of silts and clays, which is typical for the survey areas of concern, the typical sub-seabed penetration is expected to be up in excess of 10m. Sidescan sonar data were acquired using a Klein 3000 dual frequency towfish. This system collects data at 125kHz and 445kHz simultaneously. The Klein 3000 collects data at both high and low frequencies and therefore produces high quality images suitable for archaeological purposes. High and low frequency data were acquired at a range of 75m throughout the survey. Due to the number of moorings and moored vessels in the harbour navigating along planned survey lines was not always possible. However, full coverage of sidescan sonar data was ensured by acquiring sidescan sonar data at a smaller line spacing and running infill lines where necessary.

Metadata

File identifier

c5bc60cd-04e9-3862-e044-0003ba9b0d97 XML

Metadata language

English

Hierarchy level

Dataset

Date stamp

2025-06-30

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