Wednesday, 26 August 2009

CV09_03 Survey off Wexford coast

The Celtic Voyager returned to Howth harbour on the 18th August 2009 to demobilise following another successful geophysical survey of the seabed, this time off the Wexford coastline as part of the ongoing INFOMAR project. Having mobilised in Cork on the 28th July, the vessel transited to Rosslare to begin surveying along the eastern coastline of Wexford. The initial 2 weeks of the leg were spent mapping the seabed around the busy ferry and goods port of Rosslare Harbour. This data will be of great assistance to safe navigation in the area with a large portion of the approaches and the harbour itself successfully mapped. As well as this, some very interesting scientific data of the active, large-scale sand waves on the seabed off the southeast coast was also collected (see pinger data below).

Highlight image of data collected using a multibeam echosounder of the seabed around Tuscar Rock off the coast of Wexford. The image shows the shallow rock upon which Tuscar Lighthouse is built (below).

Following a change of crew and scientific staff on the 11th August, the final week of operations were concentrated along the south Wexford coast, as far west as the Saltee Islands. Mapping this area was challenging due to the combination of strong tidal currents and dangerous outcrops of rock in shallow waters.

Data from the pinger, a seismic instrument that uses sound waves to penetrate through the seabed to image the sediments beneath the seafloor in a profile view. This image captures the symmetric sand wave forms which measure over 8 metres from crest to trough and roughly 200 metres wavelength. These sand waves lie on the seabed east of the Lucifer Bank, northeast of Rosslare Harbour.

Photograph of the new INFOMAR radar tide gauge that was installed by OTT hydrometry at Rosslare Harbour to measure variations in the tide height to correct soundings taken on the vessel throughout the duration of the survey.

Photograph of a fishing vessel just offshore of Carnsore Point, on the southeast tip of Ireland taken from the Celtic Voyager.

This survey also consisted of a large portion of the South East Priority Area (off the southeast of Ireland) that will also be mapped by INFOMAR.

All INFOMAR data is available for free download here.

No comments:

Post a Comment

Note: only a member of this blog may post a comment.