KRY10_04 Blacksod Bay

The final survey undertaken in 2010 by the RV Keary was in Blacksod Bay, Co. Mayo in late September and early October. This area had existing datasets from INFOMAR surveys when Celtic Voyager mapped a large portion of the deeper water between Achill Island and the Mullet Peninsula in 2008. The other datasets seen below are a combination of LiDAR from Tenix LADS and Pelydrn campaigns in 2008 and 2010, respectively. It was left for the Keary to fill the spaces between these surveys and to run comparison cross lines to ensure that all data could be joined seamlessly upon completion of the bay. Initial progress was good, however with the beginning of October so came a deterioration in weather which limited survey operations on this exposed stretch of coast. The images below show the progress in multibeam sonar coverage until surveying was postponed on 15th October with the RV Keary returning to Dun Laoghaire for the winter.

Overview of multibeam sonar coverage achieved from KRY10_04 in Blacksod Bay, Co. Mayo. Blue hatching showing areas already covered by Celtic Voyager and LiDAR datasets.

Detail of multibeam sonar data collected south of Duvillaun More off the SW tip of the Mullet Peninsula showing outcropping bedrock with sediment accumulation in the eastern lee side of the outcrop.

Detail of multibeam sonar data collected North of Slievemore, Achill Island showing sedimentary bedforms on the seabed.

The RV Keary will return to Blacksod Bay in the near future to complete the survey and groundtruth the bay.

2010 LiDAR Surveying

From the 1st March to 17th March, INFOMAR contracted Pelydryn to perform airborne Light Detection and Ranging (LiDAR) surveys in a series of shallow water bays and loughs on the West, Northwest and North coasts. This geophysical method involves the use of eye-safe laser technology to measure water depths. It is achieved by calculating the difference between laser returns from the sea surface and the seabed.

Based at Knock and Donegal airports, Pelydryn surveyed parts of Broadhaven Bay, Blacksod Bay and Achill Sound in the Northwest. Lough Foyle, Lough Swilly and Mulroy Bay in the North. Clifden Bay, Mannin Bay, Ballyconneely Bay, Bertraboy Bay and Kilkeran Bay were surveyed in Co. Galway. Datasets collected include both marine and terrestrial LiDAR as well as aerial photographs to facilitate seamless integration of both offshore LiDAR and acoustic datasets to onshore topographic surveys.

The aircraft used by Pelydryn during the LiDAR surveys taking off from Ireland West Airport Knock. The plane was grounded on several occasions during the survey period due to volcanic ash from the Eyjafjallajokull volcano in Iceland. Nevertheless, the survey was still successful in gathering a large amount of data in areas where acoustic surveying on a boat would be time consuming and have an increased risk attached.

Coverage of LiDAR surveys in Broadhaven Bay, Blacksod Bay, Achill Sound. Previous INFOMAR survey areas shown in hatched areas.

Coverage of LiDAR surveys in Clifden Bay, Mannin Bay, Ballyconneely Bay, Bertraboy Bay and Kilkeran Bay. Previous INFOMAR survey areas shown in hatched areas.

Coverage of LiDAR surveys in Lough Foyle, Lough Swilly and Mulroy Bay. Previous INFOMAR survey areas shown in hatched areas. The outer reaches of Mulroy Bay have also been previously surveyed using LiDAR.

All INFOMAR data is available for free download here.