RV Prince Madog PD35/04

Cruise summary report

Cruise Info. 
Ship name (ship code)RV Prince Madog (74P2)
Cruise identifierPD35/04
Cruise period2004-08-18 — 2004-08-28
Port of departureMilford Haven, United Kingdom
Port of returnMilford Haven, United Kingdom
ObjectivesThe objective was to conduct a 24 hour geophysical survey in the Outer Bristol Channel using multibeam, sidescan sonar and boomer sub-bottom profiling.

The geophysical survey strategy was based on discrete corridors up to 40 km in length with kilometre wide multibeam and sidescan insonification. Eleven corridors were planned with centre lines at about 5 km spacing. Depending on water depth at least five parallel multibeam and sidescan lines were planned in each corridor. A boomer sub-bottom profiler was planned as a single line down the centre of each corridor.

The equipment deployed was:
Reson 8101 multibeam system
Klein 5000 multibeam digital sidescan capable of running at survey speeds of up to 7 knots
Applied Acoustics variable frequency surface tow boomer sub-bottom profiler
The survey strategy was devised to provide information and interpretations based on modern high resolution geophysical techniques at a scale which would identify the major sedimentary and biological regimes and also enable us to analyse the scale and relationships of the major and minor bedforms. The survey was conducted as part of a multi-disciplinary marine habitat study and was the second geophysical survey undertaken for the study.
The cruise completed multibeam and sidescan in seven of the eleven planned corridors, and surface tow boomer in three corridors. Multibeam and sidescan was also conducted along short stretches of a further two corridors. Weather and sea conditions hampered the deployment of the boomer.
Chief scientistJames William Ceri James (British Geological Survey, Keyworth)
ProjectOuter Bristol Channel Marine Habitat Study
Coordinating bodyBGS and National Museums and Galleries of Wales
Ocean/sea areas 
GeneralBristol Channel
SpecificBristol Channel
Track chartsRV Prince Madog PD35/04 cruise track — pd35_04roscop4685trk.pdf (0.10 MB) 
Geology and geophysics 
Multi-beam echosoundingQuantity: track kilometres = 1500
Description: Digital Multibeam data collected using Reson 8101 and Applanix PosMV motion sensor. Processing through Caris HPS/SIPS. Further processing and visualisation through Fledermaus software.
Long/short range side scan sonarQuantity: track kilometres = 1420
Description: Digital sidescan data collected using Klein 5000 system in CODA format. Processing through CODA Geosurvey for analysis and mosaicing.
Single channel seismic reflectionQuantity: track kilometres = 120
Description: Digital sub-bottom data collected using Applied Acoustics variable frequency boomer. Acquisition through CODA system. Recorded digitally and as analogue paper records.