The Oxygen Isotope Composition of Chironomid Chitin as a Proxy for the Oxygen Isotope Composition of Lake Water and Related Climate Parameters in Southern Spitsbergen, Svalbard, during Mid- and Late Holocene

• Main Author: Kurki, Eija
• Other Authors: Helsingin yliopisto, Matemaattis-luonnontieteellinen tiedekunta, Geotieteiden ja maantieteen laitos, University of Helsinki, Faculty of Science, Department of Geosciences and Geography, Helsingfors universitet, Matematisk-naturvetenskapliga fakulteten, Institutionen för geovetenskaper och geografi
• Format: Master Thesis
• Language: English
• Published: Helsingfors universitet 2016
• Subjects: Geography; Maantiede; Geografi; Arctic; Svalbard; Amerikan; Svartvatnet; Arktis*; Spitsbergen
• Online Access: http://hdl.handle.net/10138/230464

A sediment core from Lake Svartvatnet, Svalbard, was analysed for the oxygen isotope composition preserved in the head capsules of subfossil chironomid larvae. This provided the basis for reconstructions of past oxygen isotope composition of lake water, past mean annual oxygen isotope composition of local precipitation and the past mean annual air temperature. The reconstructions were made according to calibrations previously established for coastal northeastern North America and continental Europe. The aims of the research were to study long-term natural climate variability in a climatically sensitive area in the Arctic, and to evaluate the utilisation of the aforementioned method in such research, in particular within the environmental parameters of the study location. The core spanned over 5000 years, and the reconstructions show environmental changes related to a relatively stable mid-Holocene period, Little Ice Age, and modern warming. The mean annual temperature results were also compared with reconstructed mean July temperatures from a chironomid assemblage study. The paleotemperature trends proved fairly similar, suggesting that both proxies were principally responding to changes in temperature. This study is part of the first research project to produce paleoecologically inferred Holocene climate data, spanning thousands of years, in southern Spitsbergen. Surviaissääskitoukkien pääkapselien happi-isotooppikoostumus analysoitiin Svartvatnet-järvestä, Huippuvuorilta peräisin olevasta sedimenttikoorista. Tämän perusteella rekonstruoitiin järviveden happi-isotooppikoostumus, sadannan keskimääräinen vuotuinen happi-isotooppikoostumus ja keskimääräinen vuotuinen ilmanlämpötila tutkimusalueella yli 5000 vuoden ajanjaksolta nykyhetkestä taaksepäin. Rekonstruktiot perustuivat kalibraatioihin, jotka oli tehty koillisen Pohjois-Amerikan rannikon ja Manner-Euroopan olosuhteisiin. Tutkimuksen tarkoituksena oli selvittää pitkänajan luonnollista ilmastonvaihtelua ilmastollisesti herkällä arktisella alueella ja ...