Biogeochemical evidence for hydrologic changes during the Holocene in a lake sediment record from southeast Greenland

Bibliographic Data

ID12266919
AuthorsNicholas L Balascio (0000-0001-7106-3541, University of Massachusetts, USA, corresponding author), W J D'Andrea (0000-0003-0182-8857, Lamont-Doherty Earth Observatory), Raymond S Bradley (0000-0002-4032-9519, University of Massachusetts, USA), Bianca B Perren (Université de franche-comté), Bianca Perren (0000-0001-6089-6468, Université de franche-comté)
Year2013
Volume23
Issue10
Pages1428-1439
Publication date2013-07-18
Open AccessYes
TypeARTICLE
VenueThe Holocene (JOURNAL)
Journal identifiersISSN: 0959-6836 • E-ISSN: 1477-0911
PublisherSAGE Publishing (PUBLISHER • US)
DOI10.1177/0959683613493938
OpenAlexW2030673096
LanguageEN
Citations received1
References cited73

Holocene paleoclimate records from Greenland help us understand the response of the Greenland Ice Sheet and regional oceanic and atmospheric circulation systems to natural climate variability in order to place recent changes in a longer-term perspective. Here biogeochemical analysis of a lake sediment core from southeast Greenland is used to define changes in moisture balance and runoff during the Holocene in a catchment near the margin of the Greenland Ice Sheet. A 1.6 m sediment core that spans the last 8.8 ka was recovered from Flower Valley Lake on Ammassalik Island. Magnetic susceptibility, diatoms, bulk biogeochemical properties (TOC, C/N, δ 13 C org ), and lipid biomarkers ( n-alkanes; C 16 –C 31 ) reveal changes in clastic sedimentation and the relative input of terrestrial- and aquatic-derived organic matter. Hydrogen isotope values (δ D) of mid- ( n-C 25 ) and long-chain ( n-C 29 , n-C 31 ) n-alkanes allow reconstruction of δ D of precipitation and summertime evaporation of lake water. Following a period of early lake ontogeny and landscape stabilization after deglaciation from 8.4 to 7.0 ka, the mid Holocene, 8.4–4.1 ka, is characterized by greater evaporative enrichment of the lake water as indicated by δ D records. After 4.1 ka, there is a decrease in evaporative enrichment of the lake water. There is also an abrupt transition to more variable sedimentation marked by sharp increases in magnetic susceptibility, C/N, δ 13 C org , and the concentration of long-chain n-alkanes, showing periodic delivery of terrestrial organic matter and clastic sediment to the lake. Higher insolation during the mid Holocene resulted in a warmer and drier climate with longer ice-free periods in the summer and enhanced evaporation of lake water. The reduction in insolation and colder temperatures during the late Holocene caused a reduction in evaporation of lake water over the last 4.1 ka and was accompanied by periodic increases in surface runoff, which correspond with intervals of cold Greenland Ice Sheet surface temperatures

Biogeochemical cycle · Geography · Geomorphology · Holocene · Hydrology (agriculture · Paleolimnology · Physical geography · Sediment · Climate change and permafrost · Cryospheric studies and observations · Geology and Paleoclimatology Research · Geology · Oceanography