Glacier and climatic fluctuations inferred from tree‐growth variations over the last 250 years, central southern Norway

• Published in: Boreas
• Main Author: MATTHEWS, JOHN A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1977
• Subjects: Norway; Storbreen; glacier
• Online Access: http://dx.doi.org/10.1111/j.1502-3885.1977.tb00692.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1502-3885.1977.tb00692.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1502-3885.1977.tb00692.x

A Pinus sylvestris (Scots pine) tree‐growth series from near the tree‐line in upper Gud‐ brandsdalen, southern Norway (Slistad 1957) is analysed, and possible relationships to glacier and climatic fluctuations are explored. The series is smoothed by harmonic analysis, and calibrated using a variety of independently derived glaciological, geomorphological, and climatological data from Storbreen (Jotunheimen), the Storbreen gktschervorfeld, and Dombås meteorological station. The curves are then used to make inferences about the number, date, magnitude, and duration of glacier fluctuations and summer temperature fluctuations from 1700 A.D. to 1950 A.D. At least 10 major oscillations in the tree‐growth data, reflecting fluctuations in summer temperatures of amplitude 1.0 ° C to 3.0°C, are believed to be indicative of glacier fluctuations. Periods of reduced tree‐growth are a response to cool phases and indicate glacier advances after a lag of about 4 years. These short‐term oscillations are superimposed on a general trend of glacier retreat and a long‐term warming of 1.0°C indicated by a glacier equilibrium‐line displacement of 140 m to 145 m since 1750 A.D. Problems and prospects for development of dendroglaciological and dendro‐climatological techniques are discussed.