Wednesday 20 October 2010

INFOMAR at Geoscience Conference 2010

A two-day conference on the Geoscience Sector will take place in Dublin Castle on the 3rd and 4th November 2010. The morning sessions of the first day of the conference will focus on INFOMAR specific topics such as survey progress in 2010, the first full year of survey operations with the RV Keary and the success of the 2010 LiDAR campaign with Pelydryn.

The late morning and afternoon will look at where Irish National Seabed Survey and INFOMAR data has been and is being used in marine science research including deepwater reefs, carbonate mounds, seabed classification, seabed morphology and many other areas of research.

There is no charge for attending the event but those interested should confirm their interest by e-mailing michael.o'mahony@gsi.ie

Official agenda for both days can be found here.

Friday 15 October 2010

CV10_03 Cork and Waterford

The final INFOMAR survey of 2010 onboard the Celtic Voyager took place from the 26th September to the 5th October off the coast of Cork and Waterford from Ballycotton to Mine Head, continuing work from the second part of the CV10_02 leg earlier in the year.

Overview of multibeam sonar coverage achieved during the Celtic Voyager survey in the Southern Priority Area off Cork and Waterford.

This survey successfully joined datasets from 2008 off Cork and 2007 off Waterford and Wexford to form a continuous band of survey data from the Old Head of Kinsale, Co. Cork to Carnsore Point, Co. Wexford.


Coverage extents from INFOMAR surveys with the Celtic Voyager from 2007, 2008, 2009 and 2010 linking datasets from the Old Head of Kinsale east to Carnsore Point, covering a significant portion of the Southern Priority Area.

Multibeam sonar data of the wreck of the SS Bandon. This Irish cargo steamer of 80 metres in length was torpedoed by German U-Boat, UC-44 S of Mine Head on 13th April 1917. 28 crew were killed in the attack.

Further information on the wrecks surveyed by INFOMAR is available here.

Photograph of Ballycotton lighthouse from the Celtic Voyager.

All INFOMAR data is available for free download here.

Wednesday 13 October 2010

CV10_02 Wexford Waterford and Cork

In July, the RV Celtic Voyager continued to survey the seabed off the coast of Wexford, Waterford and Cork. This data will be included in individual INFOMAR priority bays such as Waterford Harbour and also in the Southern Priority Area which extends from Carnsore Point, Co. Wexford westward along the south coast of Ireland. This leg was divided into two parts with the first period concentrated in an area between Hook Head and the Saltee Islands, continuing on from survey coverage achieved in 2009 on CV09_03. The Celtic Voyager has now surveyed a large portion of this area and the remaining shallow, nearshore area will be finished by the RV Keary in the future.

Overview of survey work completed by the Celtic Voyager off the Wexford coast in July with existing INFOMAR survey work shown in the hatched area.


Area of detail from the multibeam sonar data for an area of seabed SW of the Great Saltee. The is an interesting feature west of the Conningmore Rocks which is possibly an area of sediment accumulation in the lee of the rocks due tidal currents. West of this feature is a shallow area of rock outcrop known as the Red Bank.

Area of detail from the multibeam sonar data for an area of rock outcrop on the seabed E of Hook Head showing complex structural geology with folding and faulting evident on the dataset. Future survey work and research may be useful in interpreting and linking these datasets to the diverse onland geology seen on Hook Head.

With the area of seabed off Wexford surveyed, operations moved down the coast to begin surveying an area that linked data acquired by the Celtic Voyager in 2008 off Cork and data from 2007 off Waterford.

Overview of survey work completed by the Celtic Voyager off the Cork and Waterford coast in July with existing INFOMAR survey work shown in the hatched area.


Plan view of multibeam sonar dataset showing the wreck of the Etal Manor on the seabed south of Hook Head. The c. 80 m Etal Manor was a British cargo steamer that was torpedoed in 1917 by German U-Boat UC-48 resulting in the deaths of 6 onboard.

Further information on the wrecks surveyed by INFOMAR is available here.

All INFOMAR data is available for free download here.

KRY10_03 Clifden and Mannin Bay

On completion of the survey portion of work in Kinsale, the RV Keary made the transit to Clifden Bay to begin mapping in Clifden Bay, Mannin Bay and the seabed outside the bays, north of Slyne Head to Cruagh Island. The inner most and shallowest areas of the bays had been surveyed using LiDAR earlier in the year. Click here for more information on that LiDAR survey.

Overview image of multibeam sonar data of all coverage achieved in Clifden and Mannin Bays. LiDAR coverage is represented by the hatched area.

Initially the survey was concentrated in the deeper water areas, seaward of the bays. It was in this area, NE of the Barret Shoals that a steep outcrop of rock rising to a chart depth of 12.2 metres in surrounding water depths of 30 to 40 metres was mapped for the first time. This significant shoal was surveyed in detail and a H102 note was prepared for the United Kingdom Hydrographic Office (UKHO) so that this shoal location can be quickly updated in the charts as a possible danger to navigation.

Datasets showing the previously uncharted shoal mapped during INFOMAR survey KRY10_03, NE of the Barret Shoals.

Multibeam sonar data showing three charted shoals mapped west of Clifden Bay during INFOMAR survey KRY10_03. The data shows that water depths are shallower (shown as red and orange colours) over these rock outcrops than the surrounding seabed (shown as green and blue colours) and can present a danger to navigation.

Entrance to Clifden Bay with the beacon on Errislanan marking the southern entrance of the bay. In the background are the Twelve Pins mountains of Connemara. The ruins of Clifden castle can also be seen in the centre of the photograph. The RV Keary anchored in Clifden Bay during the survey of Clifden and Mannin Bay.

All INFOMAR data is available for free download here.

KRY10_02 Kinsale Harbour and Approaches

Following on from survey work by the RV Celtic Voyager in 2008 of the deeper water from the Old Head of Kinsale to Ballycotton, the RV Keary completed the inshore portion of the remaining bathymetric surveying necessary for Kinsale Harbour and Approaches. This was the Keary's first survey work outside of Dublin Bay, with a successful survey of the inshore strip along the east side of the Old Head, into the harbour as far as the bridge over the river Bandon and east along the coast as far as Barry's Head.

Extent of coverage from the RV Keary survey in Kinsale with existing Celtic Voyager data shown in the hatched area.

Before the survey was commenced, a calibration of the multibeam system was necessary and the relatively deep water and defined shape of the hull of RMS Lusitania lying on the seabed off the Old Head provided a good site. One of Ireland's best known wrecks, the Lusitania was torpedoed by a German U-Boat on May 7th 1915 resulting in the deaths of over one thousand people onboard.

Plan view of EM3002 D multibeam data showing the clear outline of the hull resting on it's side. Also apparent is the fracture at mid ship seen in both the dataset above and seabed image capture below.


Oblique view of EM3002 D multibeam data point cloud showing the shape of the wreck on the seabed along the hull.


Multibeam sonar data collected west of Big Sovereign island, east of Kinsale Harbour, showing well exposed, folded and faulted bedrock on the seabed.

Further information on the wrecks surveyed by INFOMAR is available here.

All INFOMAR data is available for free download here.

Tuesday 12 October 2010

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.

Monday 11 October 2010

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.