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University College Cork (UCC) scientists have produced the
first detailed charts of part of Ireland’s offshore bedrock
geology, using a new method of mapping.
The work was undertaken by Russian-born marine geologist
Dr Max Kozachenko of UCC’s Coastal and Marine Research Centre
(CMRC)
and UCC geology lecturer Dr Pat Meere.
They explain that, although extensive swathes of Ireland’s
offshore territory have been mapped by the national seabed
survey, the details of bedrock formation can be hard to determine
due to the environment’s inaccessibility.
Geological mapping relies on a combination of photographic
interpretation, processing of specialised data and field studies
- the latter being difficult or prohibitive at any depth of
water.
The team took a section of the southwest coast to conduct
extensive coastal fieldwork and to evaluate existing terrestrial
bedrock geology maps and aerial photographs.
They interpreted bathymetric data from multibeam surveys,
data from aircraft surveys and other data sets from the underwater
offshore area collected as part of the national seabed survey.
The areas chosen by the UCC scientists focused east of the
Old Head of Kinsale and west in Bantry and Dunmanus bays,
Co Cork. They noted “extensive areas of outcropping rocks”
with “clearly expressed bedding and fracture patterns on high
resolution multibeam mapping”.
“This work revealed the full complexity of performing geological
mapping in the offshore environment, where direct measurements
are near to impossible,” they state.
A thorough knowledge of geology nearby onshore is required
to come to correct conclusions about seabed topography, they
add.
They say that their “workable methodology” can be extended
to other areas using the rich source of data collected as
part of the seabed survey - run jointly by the Geological
Survey of Ireland and the Marine Institute and known as Infomar.
Infomar (Integrated Mapping for the Sustainable Development
of Ireland’s Marine Resources) is a successor to the initial
Irish national seabed survey, which focused on offshore territory
extending to 10 times the island’s land size. It had mapped
81 per cent of that territory by late 2005.
The current work is focusing on inshore areas and involves
26 bays, one biologically sensitive area and three 'priority'
areas off the south and east coasts.
Source - The Irish Times
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