Science Spin November 2008

North South efforts to map the Irish offshore

By Sean Duke

The Republic of Ireland is right up with the very best in the world when it comes to marine mapping. A new joint mapping project with Northern Ireland, in an area off the northwest coast, could extend that level of expertise to all of Ireland, and be the forerunner to more north south co-operation in marine mapping. The JIBS (Joint Irish Bathymetric Survey) off the coast of Donegal and Derry, has brought the mapping agencies closer together, and has helped build momentum towards the aim of producing a marine map for all of Ireland's offshore waters, whether Irish or British.

Background

The JIBS started last November, and now completed, was led by the Maritime and Coastguard Agency, or MCA, of Northern Ireland, with the Marine Institute of Ireland. It was a €2.1 million joint-venture, funded from the EU INTERREG Programme. That programme supports many activities that can benefit Northern Ireland and the six border counties of the Republic.

The MCA and the Marine Institute submitted a joint proposal to undertake the JIBS project, which proposed to survey the seabed off the coastline of Northern Ireland and the Republic. The survey revealed detailed seabed features, and enabled the UK Hydrographic Office, and the Marine Institute to update their old marine charts. Remarkably the last time the survey area had been surveyed was in the 19th century by the British Admiralty, who used lead lines and sextants as their basic technologies.

Context

In the Republic responsibility for marine mapping rests with the Marine Institute and the Geological Survey of Ireland. Both these agencies were involved with the hugely successful Irish National Seabed Survey (INSS) as well as the more recent Integrated Marine for the Sustainable Development of Ireland's Marine Resource (INFOMAR).

These surveys of harbours, the continental shelf, and the deep offshore canyons of the Irish offshore have revolutionised what is known about the waters off our island. The surveys, the first since the days of the British Admiralty surveys of the 19th century, have opened a world of opportunity for both Ireland's researchers and its entrepreneurs. In Northern Ireland, as part of the UK, the marine mapping efforts have, up to now, not been as focussed, as the responsibility for this work lies with many different agencies, including the Maritime Coastguard Agency, the Department of the Environment, and UK HO (the United Kingdom Hydrographic Office), and individual large ports, such as the Port of London.

John Evans, Marine Institute, said that JIBS had been successful, not just in terms of gathering data, but in developing stronger north south relationships. "We have been working with the Department of Environment NI and the Maritime Coastguard Agency in the UK. What we are hoping is that it will be a precursor to enabling a Northern Ireland equivalent of the INFOMAR programme that we would co-operate with the agencies on, and have an entire map for the whole Ireland," John said.

INFOMAR is Ireland's national marine mapping programme. It is a widespread and detailed mapping programme, one that has helped propel Ireland to the top of the European marine mapping league, matched only by Norway, and to a position that experts estimate to be in the top five in the world. Originally, Ireland looked to Canada for help in establishing a marine mapping programme, now, the Canadians, one of the world's leaders in this area, are looking to Ireland for help.

Survey

The work focused on a three nautical mile coast strip, going westward from around Rathlin Island to Inishtrahull Island, off Donegal. The contract survey vessel used by the MCA was the MV Jetstream, while the Marine Institute deployed one of its own vessels, the Celtic Voyager.

Multi-beam echo sounding technology was used. This is where an instrument sends and receives beams of sound that are fired from beneath a survey ship, and are then reflected up off the seabed survey, to indicate the structures on the seabed. The signals from the seabed are received by the multi-beam instrument, processed by computers and converted into water depth data in order to produce 'bathymetric maps'.

Another technology used was the Acoustic Doppler Current Profilers, or ADCPs. This is a type of sonar that attempts to produce a record of water current velocities over a range of depths. This is used for tidal information on charts, for example.

Rob Spillard, Hydrographic Manager of the MCA and Project Leader, commented on the survey work:

"The MCAs contractors have been working since the beginning of the year in this area and, although at times hampered by severe weather, data has shown that there are some remarkable features on the seabed which were previously not known about - including caves and what may have been a lagoon. The data also shows a wreck, which is thought to be that of the SS Diamond, a steam coaster which sank after a collision with the SS Lily near Rathlin Island in 1918. All survey operations are now complete. The data will be sent to the UKHO in order to begin work on updating nautical charts and publications. Work will also now be undertaken to serve the data up on the web, so that all interested parties can gain access to it. The project is due to finish around the end of August."

Benefits

It is expected that the findings from JIBS will contribute towards increased safety for commercial and recreational sailors and fishermen and an enhanced knowledge of the biological, geological and archaeological features of this underwater area.
The project will also help to unify the marine survey standards on both sides of the border, and facilitate technology transfer between the MCA and the Marine Institute.

*To view a 3D fly through of the seabed surveyed by JIBS click here