2013 - University College Cork

RESEARCH PROJECTS
60
Geosciences and Coastal Processes
HOTSPOT ECOSYSTEM RESEARCH AND MAN’S
IMPACT ON EUROPEAN SEAS (HERMIONE)
Research Centre/Department/School:
School of Biological, Earth & Environmental Sciences
Contact PI: Andy Wheeler (a.wheeler@ucc.ie)
Researchers: Boris Dorschel
Start Year: 2009
End Year: 2012
Funding Body: EU FP7
Funding: €70k
Collaborating Partners: 38 partners including National
University of Ireland, Galway & GeoZentrum Nordbayern
Web: www.eu-hermione.net/
Cold-water coral mounds of Lophelia pertusa are widespread across the Scandinavian shelf, which
was completely ice-covered during the Last Glacial Maximum between 22 to 18 ka BP. Rapid
deglacial meltdown of the Fennoscandian inland ice and the retreat of its ice-streams freed most
of the shelf of ice by ˜15 ka BP. However, cold-water coral growth commenced only after the
Pleistocene-Holocene transition at 11.65 ka BP, when modern-like climatic patterns and oceanographic
conditions were established. A tight climatic coupling has been constrained with U-series
ages. Coupled 14 C ages provide local reservoir ages from various gravity cores in a fjord-setting in
Stjernsund at 70°N and on the open shelf in Trænadjupet at 66°N. Reinvestigation of earlier 14 C
coral chronologies suggests that coral ecosystems widely established themselves across the entire
3000 km long Scandinavian shelf prior to ˜10 ka BP. The earliest occurrence of Madrepora oculata
at ˜2.4 ka BP suggests a late Holocene colonization of the Norwegian shelf, which is linked to a
prominent mound growth hiatus in Trænadjupet (64°N). Mound growth rates near the northern
biogeographic boundary of L. pertusa with up to ˜614 cm ka -1 during certain growth periods are
much higher than the previously reported fastest rates of ˜220 cm ka -1 from the Irish margin. Contemporaneous
rapid fjordbasin sedimentation is slower with ˜63 cm ka -1 . Matrix 14 C ages overlap
with coral 14 C ages from the same horizon. This indicates rapid framework construction and efficient
trapping of background sediment. Hiatuses are frequent in on-mound sediments and only
short periods of coral growth are recorded. Coupled Δ 14 C and εNd values indicate a persistent
Holocene inflow of the North Atlantic Current in Stjernsund, but also deglacial meltwater mixing
during the early Holocene prior to ˜9.5 ka BP. Reservoir ages are overall close to the surface marine
reservoir age, but ΔR is highly localized (Lopez Correa et al., 2012).
KEY PUBLICATIONS & OUTPUTS
Lopez Correa, M., Montagna, P., Joseph, N., Ruggesberg, A., Fietzke, J., Flogel, S., Dorschel, B., Goldstein, S.L.,
Wheeler, A., Freiwald, A. (2012). Preboreal onset of cold-water coral growth beyond the Arctic Circle revealed by
coupled radiocarbon and U-series dating and neodymium isotopes. Quaternary Science Reviews, 34, 24-43.