October 6, 2017
Klinaklini Glacier, British Columbia Retreat Generates Large Icebergs
Posted by Mauri Pelto
Klinaklini Glacier comparison in Landsat images from 1987 and 2017. Red arrow 1987 terminus, yellow arrow 2017 terminus and snowline at purple dots.
Klinaklini Glacier is the largest glacier in the Coast Mountains of British Columbia between Vancouver and Prince Rupert. The glaier drains west and south from Mt. Silverthrone. There is significant accumulation area above 2500 m and the glacier terminates at 300 m. GLIMS noted the area in 2004 as ~470 km2. Glaciers in this region are retreating and losing volume, Schiefer et al (2007) noted that the rate of volume loss had doubled in the most recent decade. Clarke et al (2015) modeled a 70% loss in volume of all glacier in western BC by 2100. Here we examine Landsat imagery from 1987-2017, to identify changes. In particular examining the area of large icebergs in 2015-2017 generated from a rapid calving retreat that has occurred since 2010. The glacier drains in to Knight Inlet a famous area for salmon fishing.
I first saw this glacier in 1982 and at that time it ended on an outwash plain with a narrow lake/wide river leading from the terminus. In 1987 the terminus was at this same location, red arrow, with no significant lake at the terminus. The snowline in 1987 is at 1500 m. By 1995 a lake had formed across the width of the terminus. The lake was than 600 m long and the snowline was at 1600 m. In 2010 the glacier had retreated more than 1 km across its entire 1.3 km width. The lake at the terminus had a surface area greater than 1.5 km2 and was largely filled with icebergs. The snowline in 2010 is at 1500 m. By 2013 the main proglacial lake has expanded to a length of over 2 km and remained largely filled with icebergs. Retreat from 2010-2013 was as great as the retreat from 1995 to 2010. The snowline in 2013 was at 1600 m. From 2013 to 2014 there was no real change in the terminus position and the largest iceberg remained the same, pink (1). In 2015 the snowline is at 1600 m and is at 1700 m in 2016. In the side by side comparison of the terminus in 2015, 2016 and 2017 it is apparent that there was limited retreat from 2013, and a large calving event in 2017 generating an iceberg with an area of 0.7-0.9 square kilometers, pink (2), along with other smaller icebergs. The lake is now 4 km long, yielding a retreat rate of 130 m/year from 1987-2017. Nearly 50% of the retreat occurred in 2017. In 2017 the snowline is at 1700 m as well. The high snowlines each year are leading to mass loss, which leads to reduced flow through the ablation zone. The thinning terminus due to higher ablation and less flux from above is then more prone to breakup. The Klinaklini Glacier wins the prize for the largest observed iceberg produced by a glacier in Western Canada. The retreat is similar to other valley glaciers in the region Bishop Glacier, Jacobsen Glacier, Bridge Glacier and Klippi Glacier.
Comparison of the terminus, pink dots in 2015, 2016 and 2017. The red arrow is the 1987 terminus, yellow arrow the 2017 terminus and the largest icebe
rgs also labelled.