IRELAND

If collaboration is crucial, so too, McCarron adds, is good luck: ‘Chance
plays a huge role in deciding the success or otherwise of any research
campaign. And the weather of course.’ McCarron knows well the
arbitrariness of exploratory research, especially far out at sea when time
and the elements impose constraints far beyond the ordinary. Early in
2014, he was part of an international expedition on the Explorer which
aimed to map the outer limits of the Celtic shelf off the south coast of
Ireland. The campaign was part of an on-going Irish-Italian collaboration
to locate geological evidence of former ice sheet extents around the
island of Ireland. McCarron and his colleagues were looking for evidence
of former ice presence far beyond ‘accepted’ limits, at the outer edge
of the Celtic shelf. With 12 days of funding but very poor weather, they
ended up with only a short window of 36 hours in which to get to the
outer shelf and do their work. The storms of winter 2013/2014 were
horrendous and the RV Celtic Explorer, for all its tremendous stability,
was ‘chased off’ the shelf by incoming Atlantic storms. ‘We ended up
running at full speed from 30m high “lumps” of water.’ However, what
happened in those 36 hours on the outer shelf underscores the roles of
both persistence and good fortune in Discovery Research. ‘We were
very lucky, it was so touch and go whether we could get anything other
than (recent) surface gravelly sediment, which tells you little about older
ice age events.’ Based on the best educated guesses possible, in close
collaboration with the Explorer’s officers and crew and in the face of
oncoming storms and their quickly rising seas, it was decided to keep
trying to collect longer cores from the ocean floor. Only one core with
evidence of ice presence was required to change the models of Celtic
Sea glaciation, forever. The campaign ended up recovering three. On
Core 60 of the campaign, as the barrel lifted out of the water, McCarron
noticed distinctive grey mud hanging from its tip. ‘When I saw that, I
knew, and the crew quickly learned, that was it. That’s what we were
looking for. Stiff muddy sediment is like a fingerprint of ice presence.
Without ice sitting on the shelf there, you couldn’t get that level of
consolidation.’ Immediately the campaign was transformed into a success
story. Subsequent laboratory work bore this out, shells from the cores
being radio carbon-dated to the last ice age. For McCarron, the whole
episode underlined the risks, uncertainties and potential rewards of
Discovery Research. ‘We found the footprint of an ice sheet on the edge
of the Celtic shelf, which had never been suggested before. If we hadn’t
recovered these few cores in the few hours of weather window we had
available, it’s very possible that nobody else would ever have gone and
retested the same area. The word would have gone out in the scientific
community that we had tried and there was nothing there.’
‘We found the footprint of an ice sheet on the edge
of the Celtic shelf, which had never been suggested
before. If we hadn’t recovered these few cores in the
few hours of weather window we had available, it’s
very possible that nobody else would ever have gone
and retested the same area. The word would have
gone out in the scientific community
that we had tried and there was
nothing there.’ [!]
discovery Ireland 62,63