CV10_01 Irish Sea Priorty Area

INFOMAR continued to progress surveying of a priority area in the Irish Sea during April and June with the Marine Institute's research vessel Celtic Voyager. On this leg CV10_01, the survey extended from Clogher Head, Co. Louth in the north to Wicklow Head, Co. Wicklow in the south.

Overview of the area surveyed in the Irish Sea during the CV10_01 leg in April and June 2010.

During the survey, the remains of 13 ship wrecks were surveyed. These had all been previously charted however this new data will allow the locations of the wrecks to be pin pointed with greater accuracy. Initial research of existing databases suggests that 5 of the ships were sunk as a result of attacks on British merchant vessels during World War 1.

Perspective view of survey data showing the SS Hare on the seabed.

For more information about wrecks surveyed by INFOMAR visit here

Another interesting feature that became apparent on the multibeam sonar data was the presence of a number of small features in the seabed, east of Wicklow Head. Further investigation using a drop camera showed the features to be boulders up to 2 metres in size. They have been interpreted as granite boulders deposited offshore by glacial processes.

Photograph taken by an underwater camera of the boulders on the seabed off Wicklow Head.

Due to the strong tidal currents operating in the Irish Sea, the multibeam sonar data also surveyed a large scour area off the Wicklow coast. This large depression is over 100 metres deep whereas the surrounding water depth is closer to 30 metres. The feature is over 2.5 kilometres long and 600 metres wide.

Tidal scour feature surveying during the CV10_01 leg.

All INFOMAR data is available for free download here.

CV09_05 Survey off North Dublin coast

The final INFOMAR survey of the 2009 season has just been finished off the coast of north Co. Dublin. Mobilising in Galway and making a transit through heavy sea conditions, the Celtic Voyager arrived in Howth harbour on the 25th November. Surveying was concentrated to an area north of the Ben of Howth and to Skerries. The aim of the leg was to complete remaining unsurveyed areas that will allow data from three earlier survey legs to be merged together. Following this survey leg, a large portion of the Irish Sea seabed from south of Carlingford Lough to the Kish bank has been mapped.

Overview map containing multibeam echosounder dataset of the area of seabed that was surveyed during CV09_05 off the north Co. Dublin coast.

High quality shallow seismic pinger profile which penetrates beneath the seabed (to a depth of around 24 metres in this case) shows three distinct reflectors. An undulating reflector interpreted as rock or glacial sediments (blue reflector). This depression or perhaps erosion feature (channel) is filled with sediment (red reflector). A final layer of sediment, probably recent marine sediments forms what is now the current seabed (green reflector)

High quality shallow seismic pinger profile showing a distinct porabola on a section of flat seabed indictaing the possible location of a pipeline that was later confirmed on naviagtion charts.

Over the duration of the leg, weather conditions were mixed which hampered operations as poor weather effects data quality which limited the amount of surveying that can be achieved. However, all proposed survey areas were completed and some interesting datasets acquired.

During the survey, the Marine Institute's M2 oceanographic databouy was recovered to the back deck of the Celtic Voyager for repair.

The Irish Coast Guard performs training drills with the Celtic Voyager during the CV09_05 survey leg.

All INFOMAR data is available for free download here.