Evaluating the influence of coupled ocean-atmosphere circulation patterns on changes in regional climate requires proxy data such as those obtainable from ice cores. However, few options exist that record climate information before the twentieth century. Despite being a challenging location to extract a core, the Mount Logan plateau may contain some of the oldest Arctic glacier ice on Earth. It’s for this reason researchers with the University of Alberta’s Canadian Ice Core Lab are so excited to return to Mount Logan.
Climate in northwestern North America, including the coastal mountain ranges spanning British Columbia, the Yukon, and Alaska, is complex due to steep topography, ocean-land interactions, and the influence of tropical Pacific conditions. To better understand modern and past climate variability in this region, we will conduct a detailed geophysical (ice penetrating radar and GPS) survey of the summit plateau on Mount Logan in 2020, and drill a surface-to-bedrock ice core on the summit plateau (~5300m elevation) in 2021. We expect that this effort will result in a high-alpine glacier record extending into the last glacial period, provide new insights into recent ocean-atmosphere variability affecting the coastal ranges, and will also enable unique and valuable education and outreach opportunities.
The new Mount Logan ice core will lead to an evaluation of North Pacific climate variability over the last 10,000 years, contributing to our understanding of the regional responses of coupled climate systems such as the El Niño Southern Oscillation (ENSO) during past climate changes. Tropical influence on North Pacific and Arctic climate is clear in the instrumental record, but the stability of these relationships during the Holocene remains uncertain. The ice coring campaign will be used to extend the North Pacific ice core climate record, providing precipitation, temperature, and atmospheric circulation targets for Earth system models during important Holocene and late Pleistocene intervals (e.g., Last Glacial Maximum, Younger Dryas, Holocene Thermal Maximum, Medieval Climate Anomaly, Little Ice Age) and abrupt events (e.g., the last glacial termination, 8,200 and 4,200 year events). The geophysical and ice core data produced in this project will therefore have broad implications for understanding the role of coastal mountain ranges and glaciers in the regional and global climate system.
Advances in drill site selection through improved ground-penetrating radar and numerical modelling techniques, and improved core processing through high-resolution continuous melting systems, provide an unprecedented opportunity to select an ideal drill site and obtain a new ice core that contains decadal to century resolution dating back 30 ka or longer.