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.

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.

The Real Map of Ireland now in Folens Schools Atlas

A new schools atlas featuring, for the first time in the history of the State, a detailed map of Ireland’s seabed designated area was launched on Tuesday 6th April at the INTO conference in Galway. The Folens/Phillips New Irish Primary Atlas features “The Real Map of Ireland”, the results of detailed seabed mapping undertaken by the Marine Institute and the Geological Survey of Ireland during the Irish National Seabed Survey and INFOMAR projects, the Petroleum Affairs Division survey of the continental shelf edge and finally the GEBCO digital atlas. The data was acquired using cutting edge multibeam sonar technology from a variety of research vessels.

“The Real Map of Ireland showing Ireland's marine territory is generating great interest,” said Noreen Sheehan, Sales and Marketing Director for Folens, “and this adds a new and vital dimension to the new schools Atlas. Many teachers are taking printed copies of The Real Map of Ireland from our stand and we look forward to seeing this interest reflected in take-up of the new publication by schools.”

The Real Map of Ireland already forms the foundation of a number of primary school lesson plans available for download free of charge from the Marine Institute’s website at www.marine.ie. These lesson plans, which are linked to the SESE primary curriculum, open the world of Ireland’s oceans and seas to teachers as cross-curricular examples in subjects including Art, Geography, History, Science and Environmental studies.

Copies of the Folens/Phillips New Irish Primary Atlas (ISBN 978-1-84741-598-1) are available from local school bookshops and regular suppliers.

Groundtruthing in Donegal and Sligo Bays

From the 6th to 8th of July 2009, a ground truthing or seabed sampling survey was undertaken in the region of Donegal and Sligo Bay.

A local vessel, the K-Mar-K from Killybegs, was chartered for this purpose. The vessels top speed of greater than 20 knots, high maneuverability and experienced crew proved highly successful for sample acquisition.

Local vessel, the K-Mar-K from Killybegs, provided the platform for the ground truthing leg.

90 proposed sample sites were identified in the area, based on bathymetric data previously collected by INFOMAR surveys and also on seabed classification map products by INFOMAR. Of these proposed locations, 80 were successfully sampled, despite adverse weather conditions.

Map of the sample locations in Donegal and Sligo Bays .

In all instances, the 'Day Grab' was used to ensure consistency in results and due to ease of handling of this grab design. The samples recovered were described and photographed once brought on deck but will also undergo further detailed particle size analysis and will be used to refine INFOMAR seabed classification and geology products for the region.

The Day Grab (to left) on the back deck of the K-Mar-K which was used at all sampling sites.


Example of a sediment sample collected during the ground truthing leg.

The use of a suitable, locally sourced vessel capable of high-speed transits between sample locations, maximised the cost effectiveness of this sampling campaign in Donegal and Sligo Bays.

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.

RV Keary progress in Dublin Bay

Since late July, the Geological Survey of Ireland's new survey vessel, RV Keary has been making steady progress in completing the shallow water areas of Dublin Bay on survey leg KRY09_02 that were not covered by previous surveys by the Celtic Voyager. The main areas of surveying have been concentrated close to the coastline around inner Dublin Bay and on top of the shallowest areas of the Kish Bank, surveying at high spring tides to ensure safest draught clearance.

RV Keary surveying the seabed south of Dun Laoghaire in August. (Click for larger image)

To date the vessel has been operating during daylight, in weather conditions of sea state 4 or less as data quality is reduced beyond these weather conditions. Currently the crew of 4 are sufficient to perform all operation and scientific duties onboard. Weather permitting it is hoped to complete Dublin Bay by end of 2009. The RV Keary coverage will be added to by the Celtic Voyager which will be surveying in the Dublin Bay/North of Howth area in late November/early December 2009.

Overall coverage achieved by RV Keary in Dublin Bay to date. (Click for larger image)

Multibeam echosounder shaded relief image of the shallowest ridge of the Kish Bank. (Click for larger image)

Multibeam echosounder shaded relief image of the Rossbeg Bank located south east of the Baily on Howth Head. (Click for larger image)

RV Keary returning to Dun Laoghaire marina after another day of successful surveying. (Click for larger image)

More information about the RV Keary can be found here.

All INFOMAR data is available for free download here.

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.