Lowell Glacier is a large glacier located in Kluane National Park. It is approximately 70 km long and averages 5 km wide. The glacier terminates in Lowell Lake at approximately 500 m elevation, and about 60 km southwest of Haines Junction. The Alsek River flows into Lowell Lake from the north and exits the south end of the lake.
Glacier surges are short periods of rapid glacier advance, likely caused by sudden changes in hydrological conditions beneath a glacier. Surging activity typically lasts for a year or two and occurs every decade or two. Lowell Glacier most recently surged in 2009-2010. Prior to that, Lowell Glacier surged in 1998-1999, 1983-1984, 1968-1970 and 1948-1950.
At least five times in the past 3000 years, Lowell Glacier has surged as far as Goatherd Mountain, damming the Alsek River and impounding a large lake that extended up the Alsek River valley to Haines Junction and into the Dezadeash River valley. This lake is referred to as “Neoglacial Lake Alsek”. The last time Neoglacial Lake Alsek formed was around 1850, at the end of the Little Ice Age. Neoglacial Lake Alsek also formed at least 3 times between about 1500 and 1800 A.D., and once more between 800 and 2900 years ago (Clague & Rampton, 1981). The largest of these lakes extended over 100 km, and reached depths of 200 m, making it possibly the largest Neoglacial lake in North America.
Based on 1975-1979 discharge levels for Alsek River, it is estimated that once the Lowell Glacier dammed the Alsek River, the lake would have taken a year to reach Haines Junction, and over 5 years to reach its maximum extent. Eventually the glacier dams failed and each of the lakes drained catastrophically down the Alsek River into the Pacific Ocean at Dry Bay, Alaska. The floods produced giant ripples that are still visible in the Alsek River valley.
Other evidence that provides a glimpse into the Neoglacial Lake Alsek history includes: staircase sets of raised beaches (visible from the Alaska Highway near Bear Creek), wave cut benches, driftwood layers along beaches, lichen density and size along river terraces, sequences of former lake sediments and buried soils, and the presence of ice-rafted erratics. A carved wooden paddle over 2 m in length was also found in the Alsek Valley (Clague & Rampton, 1981).
Before the onset of the most recent (2009-2010) surge, the distance between the glacier terminus and the base of Goatherd Mountain on the opposite side of Lowell Lake was about 4 km. By late spring 2010, the glacier terminus had advanced up to 2.5 km past its pre-2009 position to within about 1 km of the base of Goatherd Mountain. Lowell Lake was choked with calved ice and made passage for Alsek River rafters a challenge.
Even if the next surge causes the Lowell Glacier to reach Goatherd Mountain and dam the Alsek River, the lake will not likely flood Haines Junction. This is because the Lowell Glacier has thinned so much in the last century that it can not form a high enough dam to create a lake that would extend as far as Haines Junction.
Yukon Geological Survey is currently collaborating with the U.S. Geological Survey, University of Ottawa and Parks Canada to continue monitoring long-term glacier dynamics (surging, retreat and calving activity) and baseline climatic conditions at the terminus of Lowell Glacier. In 2010, YGS installed an automatic weather station, webcam and time lapse camera on a ridge above the southern flank of the glacier. Links to these data are provided below.
View of Lowell glacier terminus before the onset of the present surge
(photo taken Sept. 16, 2009). Alsek River enters Lowell Lake at bottom right.
Lowell Glacier viewed from Goatherd Mountain (June 14, 2010).
Weather station (left mast) and time-lapse camera/webcam (right mast)
installed on ridge above south flank of Lowell Glacier (May 31, 2010).
• Real-time Lowell Glacier weather data, updated hourly
• Most recent webcam images
• Annotated description of webcam view [1.3 MB ]
• Lowell Glacier map
• 2010 research progress report (insert hyperlink)
This time lapse video spans the time period: May 31 to August 6, 2010
Clague, J.J. and Rampton, V.N., 1982. Neoglacial Lake Alsek. Canadian Journal of Earth Sciences, vol. 19, issue 1, pp 94-117.
Clarke, G.K.C. and Holdsworth, G, 2002. Glaciers of the St. Elias Mountains. In: Glaciers of North America, edited by R.S. Williams and J. G. Ferrigno. U.S. Geological Survey professional paper 1386-J-1, pp J301-J328.