Most glaciers in the British Columbia Coast Mountains reached their maximum Holocene extent during the Little Ice Age. Early- and late-Little Ice Age intervals of expansion and retreat fluctuations describe a mass-balance response to changing climates. Although existing dendroclimatic records provide insights into these climatic fluctuations over the last 400. yr, their short durations prohibit evaluation of early-Little Ice Age climate variability. To extend the duration of these records, submerged coarse woody debris salvaged from a high-elevation lake was cross-dated to living chronologies. The resulting chronology provides the opportunity to reconstruct a regional June-July air-temperature anomaly record extending from AD. 1225 to 2010. The reconstruction shows that the intervals AD. 1350-1420, 1475-1550, 1625-1700 and 1830-1940 characterized distinct periods of below-average June-July temperature followed by periods of above-average temperature. Our reconstruction provides the first annually resolved insights into high-elevation climates spanning the Little Ice Age in this region and indicates that Little Ice Age moraine stabilization corresponds to persistent intervals of warmer-than-average temperatures. We conclude that coarse woody debris submerged in high-elevation lakes has considerable potential for developing lengthy proxy climate records, and we recommend that researchers focus attention on this largely ignored paleoclimatic archive. © 2012 University of Washington.
Pitman, K. J., & Smith, D. J. (2012). Tree-ring derived Little Ice Age temperature trends from the central British Columbia Coast Mountains, Canada. Quaternary Research (United States), 78(3), 417–426. https://doi.org/10.1016/j.yqres.2012.08.009