By Johannes Koch and John Clague
We would like to alert you to a new study that we are conducting in Garibaldi Provincial Park. The study focuses on environmental change in the subalpine/alpine regions of the park during and before the 20 th century.
The project commenced in the spring of 2002 and will continue until 2006 in the form of a Ph.D. study in the Department of Earth Sciences at Simon Fraser University. Several glaciers will be visited, and moraines and other glacial features will be mapped and dated. Our objective is to learn what drives glacier fluctuations in the southern Coast Mountains of British Columbia. Tree rings will be used to reconstruct climate in past centuries. Trees archive climatic influences like temperature, precipitation, and snowpack. By measuring the width of annual rings, we can make inferences about climate during any given year. By comparing the environmental information gained from tree rings and former glacier margins, we gain a better understanding of how future climatic change may affect the subalpine and alpine regions of the park and the southern Coast Mountains in general. The study will also provide insights into how climate change might affect tourism in the area.
This year we visited Overlord Glacier east of Whistler Mountain near Russet Lake, Sphinx and Sentinel Glaciers at Garibaldi Lake, Garibaldi and Lava Glaciers in the Diamond Head area, and Stave Glacier in the far southeast corner of the Park on the boundary with Golden Ears Provincial Park. All glaciers have downwasted and receded since the Little Ice Age, a period of cool climate that ended in the mid- to late 19 th century. Recent recession is inferred from the barren, poorly vegetated ground in front of present-day glacier termini. Similar glacier recession has been documented in all mountain ranges in world. Fossil wood in the moraines provides ages for several periods during which glacier cover was much more extensive than today and indicate that glaciers are shrinking to positions they last saw about 7,000 years ago.
In Garibaldi Provincial Park, we have an opportunity to directly reconstruct glacier changes from as early as 1912. The following photographs, for example, show the terminus of Helm Glacier in 1928/1929 and 2002. Note the huge amount of ice loss over this period. Such changes have impacts downvalley from the glaciers and also on outdoor recreation and tourism. As glaciers recede and, in some cases, disappear, stream flow may decrease, affecting fish populations, power generation, and water supply. Glaciers in the Park are eye-catchers and a major reason that hikers visit the alpine regions of the park. Imagine what a different place the park would be with no glaciers.
PIC 1
Helm Glacier in 1928 (top - B.C. Archives I-67145 & I-67146) and 2002 (bottom - J. Koch photo).
Similarly, pictures taken in 1928 and 2002 show changes in vegetation in Black Tusk Meadows and on Panorama Ridge. Vegetation cover has become more extensive and less patchy, as trees have filled in islands in the former open parkland. Trees have also become established farther upslope, indicating that climate became more favourable for tree growth in the subalpine zone in the 20 th century. Such changes can adversely impact some wildlife, which depends on these open spaces, and outdoor recreation because people find subalpine meadows appealing. The showy summer flower displays in the meadows are a major attraction for visitors to Garibaldi Park.
Next year, we will study Wedgemount Glacier in the northern part of the park, glaciers in the Spearhead Range east of Blackcomb Mountain, Helm Glacier near Taylor Meadows, glaciers in the Diamond Head area, and glaciers at Snowcap Lake in the central part of the park east of Garibaldi Lake. Black Tusk Meadows and Panorama Ridge will be also visited to verify and better understand the 20 th century changes in vegetation cover.
Because our collections of photographs of the park is limited, we would appreciate hearing from you if you have any pictures of glaciers in the park dating from the period 1900-1950. Furthermore, please pass along anything that you feel would be interesting and relevant to our study. We are looking forward to hearing from you.
Johannes Koch
jkoch@sfu.ca
(604)291-3856
John J. Clague
jclague@sfu.ca
