TY - JOUR
T1 - Lake and catchment response to Holocene environmental change: Spatial variability along a climate gradient in southwest Greenland
AU - Anderson, N.J.
AU - Liversidge, A.C.
AU - McGowan, S.
AU - Jones, M.D.
N1 - CODEN: JOUPE
Funding details: Natural Environment Research Council, NERC, NRCF010001
Funding details: National Eye Research Centre, NERC
Funding details: Royal Geographical Society, RGS
Funding details: University of Nottingham
Funding text 1: Acknowledgments We thank William D’Andrea, Tessa Needham and Kent Joensen for help with fieldwork, Jesper Olsen for the 14C chronologies, and Mike Marshall for help with the XRF analyses. Dating was funded by NERC (awards to NJA and SMcG), thanks to Charlotte Bryant at the NERC radiocarbon laboratory. Fieldwork was funded by a University of Nottingham New Lecturer’s Award to SMcG and a Royal Geographical Society Postgraduate Travel Bursary to ACL. Three anonymous reviewers provided helpful comments on an earlier draft.
PY - 2012
Y1 - 2012
N2 - The Kangerlussuaq area of southwest Greenland is a lake-rich landscape that covers a climate gradient: a more maritime, cooler and wetter coastal zone contrasts with a dry, continental interior. Radiocarbon-dated sediment sequences (covering ~11,200-8,300 cal year) from paired lakes at the coast and the head of the fjord were analysed for lithostratigraphic variables (organic-matter content, bulk density, Ti, Ca). Minerogenic and carbon accumulation rates from the four lakes were compared to determine catchment and lake response to Holocene climatic variability. Catchment erosion at the coast was dominated by cryonival processes, with considerable sediment production due to the limited vegetation cover and exposed rock faces. Input of minerogenic sediment at one site (AT4) was high (>1 gDW cm -2 year -1) during the period 5,800-4,000 cal year BP, perhaps reflecting intensification of cryogenic processes on northeast-facing slopes and rapid delivery to the lake. This period of erosional activity was not observed at the nearby, higher elevation site (AT1) due to the lower catchment relief; instead, there was an abrupt decline in carbon and minerogenic accumulation rates at ~5,800 cal year BP. Sediment accumulation rates at the inland sites were much lower (<0. 005 gDW cm -2 year -1) reflecting greater catchment stability (more extensive vegetation cover), lower relief and substantially lower precipitation, but synchronous increases in mineral accumulation rates from ~1,200 to 1,000 cal year BP may reflect wind erosion associated with regional cooling and local aridity. Carbon-accumulation-rate profiles were similar at the two inland sites, with higher-than-average accumulation (~6-8 g C m -2 year -1) during the early Holocene and a subsequent decline after ~6,000 cal year BP. At the inland lakes, both mineral and carbon accumulation rates exhibited a stronger link to climate, driven by trends in effective precipitation and regional aeolian activity. Catchment differences (relief, altitude) lead to more individualistic records in both erosion history and lake productivity at the coast.
AB - The Kangerlussuaq area of southwest Greenland is a lake-rich landscape that covers a climate gradient: a more maritime, cooler and wetter coastal zone contrasts with a dry, continental interior. Radiocarbon-dated sediment sequences (covering ~11,200-8,300 cal year) from paired lakes at the coast and the head of the fjord were analysed for lithostratigraphic variables (organic-matter content, bulk density, Ti, Ca). Minerogenic and carbon accumulation rates from the four lakes were compared to determine catchment and lake response to Holocene climatic variability. Catchment erosion at the coast was dominated by cryonival processes, with considerable sediment production due to the limited vegetation cover and exposed rock faces. Input of minerogenic sediment at one site (AT4) was high (>1 gDW cm -2 year -1) during the period 5,800-4,000 cal year BP, perhaps reflecting intensification of cryogenic processes on northeast-facing slopes and rapid delivery to the lake. This period of erosional activity was not observed at the nearby, higher elevation site (AT1) due to the lower catchment relief; instead, there was an abrupt decline in carbon and minerogenic accumulation rates at ~5,800 cal year BP. Sediment accumulation rates at the inland sites were much lower (<0. 005 gDW cm -2 year -1) reflecting greater catchment stability (more extensive vegetation cover), lower relief and substantially lower precipitation, but synchronous increases in mineral accumulation rates from ~1,200 to 1,000 cal year BP may reflect wind erosion associated with regional cooling and local aridity. Carbon-accumulation-rate profiles were similar at the two inland sites, with higher-than-average accumulation (~6-8 g C m -2 year -1) during the early Holocene and a subsequent decline after ~6,000 cal year BP. At the inland lakes, both mineral and carbon accumulation rates exhibited a stronger link to climate, driven by trends in effective precipitation and regional aeolian activity. Catchment differences (relief, altitude) lead to more individualistic records in both erosion history and lake productivity at the coast.
KW - Cryo-nival
KW - DOC
KW - Erosion
KW - Productivity
KW - Sediment transport
U2 - 10.1007/s10933-012-9616-3
DO - 10.1007/s10933-012-9616-3
M3 - Article
SN - 0921-2728
VL - 48
SP - 209
EP - 222
JO - Journal of Paleolimnology
JF - Journal of Paleolimnology
IS - 1
ER -