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Evaluating Holocene Climate Change In Northern Norway Using Sediment Records From Two Contrasting Lake Systems., Nicholas L. Balascio, Raymond S. Bradley
Evaluating Holocene Climate Change In Northern Norway Using Sediment Records From Two Contrasting Lake Systems., Nicholas L. Balascio, Raymond S. Bradley
Raymond S Bradley
We analyzed Holocene sedimentary records from two lakes in the Lofoten Islands, northern Norway to evaluate environmental changes during the Holocene related to northern North Atlantic climate dynamics. The lakes are located in different geomorphological settings, and thus provide a contrast in their response to regional climate change. Environmental changes at both lakes were interpreted based on magnetic susceptibility, organic-matter flux, C/N, d13 Corg , Ti concentrations, and mass accumulation rates. Chronologies were established using 16 AMS radiocarbon dates, and average deposition rates in both environments are higher than 0.2 mm/year throughout the Holocene. At Vikjordvatnet, sedimentary geochemical properties define …
Lacustrine Records Of Holocene Climate And Environmental Change From The Lofoten Islands, Norway, Nicholas L. Balascio
Lacustrine Records Of Holocene Climate And Environmental Change From The Lofoten Islands, Norway, Nicholas L. Balascio
Open Access Dissertations
Lakes sediments from the Lofoten Islands, Norway, can be used to generate well resolved records of past climate and environmental change. This dissertation presents three lacustrine paleoenvironmental reconstructions that show evidence for Holocene climate changes associated with North Atlantic climate dynamics and relative sea-level variations driven by glacio-isostatic adjustment. This study also uses distal tephra deposits (cryptotephra) from Icelandic volcanic eruptions to improve the chronologies of these reconstructions and explores new approaches to crypto-tephrochronology. Past and present conditions at Vikjordvatnet, Fiskebølvatnet, and Heimerdalsvatnet were studied during four field seasons conducted from 2007-2010. Initially, each lake was characterized by measuring water …
A High-Resolution Temperature Record From Lakes Of The Lofoten Islands, Northwestern Norway Based On A New Uk37 Temperature Calibration From In Situ Measurements, Xiaohui Huang
Masters Theses 1911 - February 2014
Water filters and sediment trap samples were collected weekly from late May to early September 2009 from four lakes of the Lofoten archipelago, northwestern Norway, and were used to explore the applicability of the alkenone unsaturation index (UK37) for temperature reconstruction in limnic systems in the area. For the first time, we observed the occurrence of long-chain alkenones (LCAs) within the water columns of lakes in this region. Water filters from two of the four studied lakes contained measurable concentrations of alkenones that were restricted to spring turnover and disappeared with the onset of summer stratification. These results indicate that …
Distal Tephra Found In A Viking Boathouse: The Potential For Tephrochronology In Reconstructing The Iron Age In Norway, Nicholas L. Balascio, Stephen Wickler, L E. Narmo, Raymond S. Bradley
Distal Tephra Found In A Viking Boathouse: The Potential For Tephrochronology In Reconstructing The Iron Age In Norway, Nicholas L. Balascio, Stephen Wickler, L E. Narmo, Raymond S. Bradley
Raymond S Bradley
Distal tephra deposits from Icelandic volcanic eruptions have been found in Norway and can be used to precisely date a variety of sedimentary environments. Tephrochronology has not yet been applied to archaeological investigations in Norway because tephra are generally not found as visible layers, but are present as very low concentrations of glass shards (i.e. cryptotephra). In this study, we present results from the analysis of cryptotephras found in an Iron Age boathouse in northern Norway. The boathouse was associated with the chieftain center at Borg on Vestvågøy in the Lofoten Islands. In 2003, a trench was excavated and the …
A Multi-Proxy Approach To Assessing Isolation Basin Stratigraphy From The Lofoten Islands, Norway, Nicholas L. Balascio, Zhaohui Zhang, Raymond S. Bradley, Bianca B. Perren, Svein-Olaf Dahl, Jostein Bakke
A Multi-Proxy Approach To Assessing Isolation Basin Stratigraphy From The Lofoten Islands, Norway, Nicholas L. Balascio, Zhaohui Zhang, Raymond S. Bradley, Bianca B. Perren, Svein-Olaf Dahl, Jostein Bakke
Raymond S Bradley
This study takes a comprehensive approach to characterizing the isolation sequence of Heimerdalsvatnet, a coastal lake in the Lofoten Islands, northern Norway. We use established methods and explore new techniques to assess changes in marine influence. Bathymetric and sub-bottom profiles were acquired to examine basin-wide sedimentation and a 5.8 m sediment core spanning the last 7800 cal yr BP was analyzed. We measured magnetic susceptibility, bulk organic matter properties, molecular biomarkers, diatom assemblages, and elemental profiles acquired by scanning X-ray fluorescence. These characteristics of the sediment reflect detailed changes in salinity and water column conditions as the lake was progressively …