Arctic coastal barriers: a long-term record of rapid environmental changes


OCCI Funded Project: 2007


Low-lying Arctic coasts have experienced numerous episodes of erosion and retreat in their geologic history. Recent rise in temperature, reduction in sea-ice cover, and melting of coastal permafrost are predicted to make coastal regions more vulnerable to erosion in the future. Along sandy coasts, extreme events often leave diagnostic morphological and sedimentological signatures in ancient beach and dune deposits. The combination of high-resolution subsurface imaging with optical dating of individual event horizons can be used to reconstruct regional histories of extreme events in the Arctic. The proposed investigation focuses on coastal sites in Kotzebue Sound, Alaska where both Pacific and Arctic storms are recognized as important agents of coastal change.This research will extend the instrumental records of large-magnitude erosional episodes, while refining the existing chronology of storminess and climatic change as far back as 5,000 years.Integrating field research with theoretical numerical modeling, the proposed project will not only shed light on the local record of climactic change, but will aid in developing our understanding of how beach ridge orientation responds to changes in wave climate. This research is part of a larger initiative aimed at reconstructing the return periods of major climatic and oceanographic events and to assessing their future impact on Arctic coasts.