Authors: Dan Smith*, University of Victoria
Topics: Paleoenvironmental Change, Physical Geography, Cryosphere
Keywords: Dendroglaciology, tree rings, glaciers, British Columbia
Session Type: Paper
Start / End Time: 11:10 AM / 12:25 PM
Room: Governors Square 15, Sheraton, Concourse Level
Presentation File: No File Uploaded
The British Columbia Coast Mountains lie between the Pacific Ocean and Interior Plateau of western Canada. Glaciers in this region reached their Holocene maximum positions during the Little Ice Age and have been decreasing in size for most of the past century to reveal the remains of glacially-overridden trees and buried forests. Located below till and outwash deposits of variable age, dendroglaciological investigations of these subfossil stump and bole remains by UVTRL researchers and others at over 70 glaciers reveals the regional character of glacier activity following the early Holocene warm period. Widespread glacier advances into mature valley-bottom and valley-side forests in 6.7-5.6 ka were followed by punctuated advances of variable duration in 5.1-4.6, 4.4-4.0, 3.8-3.4, 3.2-2.8, and 2.3-1.9 ka. Regional ice expansion between 1.5-1.1 ka proceeded Little Ice Age terminus fluctuations from 0.9 to 0.1 ka. The majority of these advances have regional and global correlatives, reinforcing the persistent role of broad-scale climate forcing mechanisms on glacier mass balance. Noteworthy in the British Columbia Coast Mountains is the ongoing emergence, along the periphery of many glaciers, of the remains of mature forests overwhelmed by a singular mid-Holocene advance. This discovery emphasizes the significance of present-day glacier losses in the British Columbia Coast Mountains, as it becomes increasingly apparent that glaciers in this region are smaller today than at any time within the last 7000 years.