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Late Glacial and Holocene environmental changes were reconstructed using physical, chemical and biological proxies in Lake Myklevatnet, Allmenningen, (5º13′17″E, 61º55′13″N) located at the northern side of Nordfjorden at the coast of western Norway. Myklevatnet (123 m a.s.l.) lies above the Late Glacial marine limit and contains sediments back to approximately 14,300 years before a.d. 2000 (b2k). Because the lake is located ~48 km beyond the margin of the Younger Dryas (YD) fjord and valley glaciers further inland, and did not receive glacier meltwater from local glaciers during the YD, the lake record provides supplementary information to Lake Kråkenes that received glacial meltwater from a local YD glacier. Lake Myklevatnet has a small catchment and is sensitive to Late Glacial and Holocene climate and environmental changes in the coastal region of western Norway. The age-depth relationship was inferred from a radiocarbon- and tephra-based smoothing-spline model with correlated ages from oxygen isotope maxima and minima in the Late Glacial sequence of the NGRIP ice core (in years b2k) to refine the basal chronology in the Myklevatnet record. The results indicate a two-step YD warming, colder early YD temperatures than in the later part of the YD, and considerably more climate and environmental variability during the late Holocene in western Norway than recorded previously in the oxygen isotopes from Greenland ice cores. The Myklevatnet record is also compared with other Late Glacial and Holocene terrestrial and marine proxy reconstructions in the North Atlantic realm. [ABSTRACT FROM AUTHOR]

Abstract: Here we present a Holocene record of glacier variability as documented through physical sediment properties analysed on sediments from the distal glacier-fed Lake Nedre (Nedre = Lower) Sørsendalsvatn (918 m a.s.l.), located 35 km inland from the coast in western Norway. We emphasise comparing different sediment parameters by means of statistical methods as well as integrating chronological uncertainties along with uncertainties of reconstructed glacier variability. A multi-proxy data set consisting of sedimentological, physical, and geochemical data shows one main process, as extracted by means of principal component analysis (88% of the variance explained by the first PC), driving sediment variability in Nedre Sørsendalsvatn. The common signal extracted from the sediment data is indicative of glacial activity in the catchment and is interpreted to vary in concert with the changing glacier equilibrium-line altitude. The reconstruction of former glacier activity is in accordance with glacier variability reconstructed from other sites in western Norway, including the termination of the deglaciation at approximately 10,000 cal yr BP, the 8.2 ka BP (Finse) event, the Holocene thermal optimum between ∼8000 and 5500 cal yr BP, and the onset of the Neoglacial at 5500 cal yr BP. The largest glacial extent during the Neoglacial time period took place during the ‘Little Ice Age’. The combined radiocarbon chronologies from three different sediment cores provide insight into the duration of the “8.2 ka event” in the terrestrial system. The maximum glacier activity at approximately 8.2 cal BP is the culmination of a glacier advance that began around 9 cal BP and accelerated at 8.4 cal BP. The glacier advance ended abruptly at 8.0 cal BP. [Copyright &y& Elsevier]

Late Glacial and Holocene glacier fluctuations are important indicators of climate variability in the northern polar region and contain knowledge vital to understanding and predicting present and future climate changes. However, there still is a lack of robustly dated terrestrial climate records from Arctic Norway. Here, we present a high-resolution relative glacier activity record covering the past ∼10,000 cal. a BP from the northern outlet of the Langfjordjøkelen ice cap in Arctic Norway. This record is reconstructed from detailed geomorphic mapping, multi-proxy sedimentary fingerprinting and analyses of distal glacier-fed lake sediments. We used Principal Component Analysis to characterize sediments of glacial origin and trace them in a chain of downstream lakes. Of the variability in the sediment record of the uppermost Lake Jøkelvatnet, 73% can be explained by the first Principal Component axis and tied directly to upstream glacier erosion, whereas the glacial signal becomes weaker in the more distal Lakes Store Rundvatnet and Storvatnet. Magnetic susceptibility and titanium count rates were found to be the most suitable indicators of Holocene glacier activity in the distal glacier-fed lakes. The complete deglaciation of the valley of Sør-Tverrfjorddalen occurred ∼10,000 cal. a BP, followed by a reduced or absent glacier during the Holocene Thermal Optimum. The Langfjordjøkelen ice cap reformed with the onset of the Neoglacial ∼4100 cal. a BP, and the gradually increasing glacier activity culminated at the end of the Little Ice Age in the early 20th century. Over the past 2000 cal. a BP, the record reflects frequent high-amplitude glacier fluctuations. Periods of reduced glacier activity were centered around 1880, 1600, 1250 and 950 cal. a BP, while intervals of increased glacier activity occurred around 1680, 1090, 440 and 25 cal. a BP. The large-scale Holocene glacier activity of the Langfjordjøkelen ice cap is consistent with regional temperature proxy reconstructions and glacier variability across Norway. Long-term changes in the extent of the northern outlet of the Langfjordjøkelen ice cap largely followed trends in regional summer temperatures, whereas winter season atmospheric variability may have triggered decadal-scale glacial fluctuations and generally affected the amplitude of glacier events. [ABSTRACT FROM AUTHOR]