Dendrogeomorphology as a tool to unravel snow-avalanche activity: Preliminary results from the Fnjóskadalur test site, Northern Iceland

Abstract

Snow avalanches are a major hazard for many settlements and transportation corridors in northern Iceland. At many sites the occurrence of snow avalanches during the past century has not been recorded. Visible damage, such as tilting, scars and decapitation of trees and shrubs (Betula pubescens) growing on colluvial cones in a remote area in Central North Iceland clearly identifies snow-avalanche paths of a given magnitude and frequency. An analysis of tree-ring data was made using the chronology of ring sizes and wood reaction in snow-avalanche tracks subject to frequent avalanches. Abnormal growth, correlated with abrupt increases or decreases in growth rates, is related to snow-avalanche impact. The preliminary results provide reliable dendrogeomorphological data that show the spatial extent and frequency of snow avalanches in the study area. Further investigation that includes a broader sampling strategy and dendrochronological laboratory analysis is required.

Keywords:

• dendrochronology
• dendromorphology
• Iceland
• snow avalanches

Acknowledgements

Financial support was received from the Natural Research Centre of Northwest Iceland, Sauðárkrókur, Iceland, from the Geolab CNRS UMR 6042 Laboratory of Physical and Environmental Geography, Clermont-Ferrand, France, and from the Arctic Research Network, Besançon, France. The authors thank Erik Grüneberg, Elisabeth Janssen, Helgi Páll Jónsson, and Olga Sandberg for the helpful assistance they provided during the fieldwork. The authors are grateful to the reviewers for their constructive comments on the manuscript.

Notes

1. http://www.binetruy-sarl.com/catalogue/p30.pdf (accessed February 2007)