North Cascade Glacier Climate Project Observations 2020, 37th Field Season

On August 31, 2020April 24, 2024 By mspeltoIn glacier climate change, Glacier Observations, North Cascade Glaciers

The North Cascade Glacier Climate Project 2020 field season was our 37th consecutive year of glacier observations. The field team consisted of Cal Waichler, Mariama Dryak, Jill Pelto and Mauri Pelto. Each team member has studied glaciers on more than one continent and is passionate about science communication, using either art, videography or writing.

Mauri Pelto, Jill Pelto, Cal Waichler and Mariama Dryak from left to right on Easton Glacier the 2020 field team (Jill Pelto Photograph).

At Columbia Glacier the field team was joined by Michelle Tanz a Wlderness Stewardship Fellow for the National Forest Service. The initial observation was that the 2 km bushwhack around Blanca Lake has gotten much brushier as the alpine meadow becomes more sub-alpine. Columbia Glacier is a low elevation avalanche fed glacier that developed a new lake at its terminus a decade ago that continues to expand. The east side of the glacier has been thinning much faster than the west side altering the very shape of the glacier. Observed snowpack in 2020 was below average except for on the slopes of the main west side avalanche fans. The upper basin at 1550-1650 m averaged 2.2 m of snowpack at the 70 probing locations, which is 70% of normal. This snowpack will not survive the melt season, only snowpack in the main avalanche fans will remain. Terminus retreat has been 217 m since our first observation in 1984.

Lower Curtis Glacier is fed by avalanches from the slopes of Mt. Shuskan. We were joined in the field by Tom Hammond for the 17th consecutive year and artist Claire Giordano. There was a similar pattern to Columbia Glacier in that snowpack across most of the glacier was below average, while the primary avalanche fan on the east side had above average snowpack. The avalanche fans on the central headwall of the glacier fed from the Upper Curtis Glacier continue to thin rapdily, as avalanching has declined. The terminus slope which had been a daunting 42 degrees in 2015 is now 34 degrees. For the sixteenth consecutive year we had at least one artist in the field, below are field sketches from Cal Waichler and Jill Pelto and a painting from Claire Giordano. We will be combining the science findings and art in forthcoming articles on Lower Curtis and Easton Glacier.

Claire Giordano working on painting of Lower Curits Glacier and Mt. Shusksan (Mariama Dryak Photograph).

Jill Pelto completes sketch, while sitting on ice chunk, of Easton Glacier icefall (Mariama Dryak Photograph).

Cal Waichler annotated story board style sketches both capture and explain the scene at Columbia Glacier (Mariama Dryak Photograph).

Rainbow Glacier has a terminus that is largely buried by avalanches, but is now is close to detaching from the main valley glacier. Snowpack at 1700 m averaged 2.4 m which is 75% of average. The saddle with Mazama glacier at 2000-2100 m averaged 3.9 m, which is 85% of normal. Subglacial bedrock knobs continue to become more prominent in expanding crevassing above and slope below the slope change, as the glacier thins.

Sholes Glacier had the highest percentage of surface blue ice of the glaciers observed. Snowpack had been reduced from at a rate of 8 cm/day during the first week of August, a relatively warm period. A snow cave at the terminus could be entered from a terminus crevasse that was 50 m long, 10 m wide and 2-5 m high. This is indicative of a relatively stagnant rapidly retreating terminus. From 2014-2020 the glacier has retreated 80 m, which is equivalent to the retreat from 1990-2014. Glacier runoff continues to be monitored just below the glacier by the Nooksack Tribe, while we provide continued rating curve development. Runoff during early August was averaging 0.25 m³/sec.

On Easton Glacier the terminus slope was the gentlest we had seen in our 31 years of consecutive observations. The terminus has retreated 430 m in this period. The significant thinning in the last few years had both reduced crevassing in the lowest icefall, but had reduced crevasse depth. Jill Pelto has been observing the crevasses depth in all the open crevasses in this icefall over the last decade. The biggest change has been from 2018-2020 with average depth being reduced by 40%. Snowpack on the bench at 2000 m averaged 2.4 m at the 45 observation sites, which is 75% of normal. The snowpack remained below normal at 2200 m, before a sharp increase to above normal snowpack averageing 5.1 m in 14 crevasse observations at ~2500 m. At this same elevation retained snowpack, now firn from previous years averaged 2.25 m. Based on the storm stratigraphy one significant difference was the result of an atmospheric river precipitation event of 12+ cm of precipitation from 1/31-2/2, that led to a snow depth and snow water equivalent decline at the Middle Fork Nooksack Snotel at 1550 m, while above 2300 m this all fell as snow. The freezing levels were above 2000 m for much of the event. The better high elevation snowpack will help Easton Glacier’s mass balance in 2020.

Easton Camp from adjacent to 1990 terminus position (Jill Pelto Photograph).

Crevasse stratigraphy at 2500 m on Easton Glacier indicates an average of 5.1 m of 2020 snowpack in crevasses and 2.25 m for previous annual layers from the 2016-2019 period (Mauri Pelto and Jill Pelto Photographs)

North Cascade Glacier Climate Project Observations 2020, 37th Field Season

On August 30, 2020April 24, 2024 By mspeltoIn Glacier Observations

Mauri Pelto, Jill Pelto, Cal Waichler and Mariama Dryak from left to right on Easton Glacier the 2020 field team (Jill Pelto Photograph).

At Columbia Glacier the field team was joined by Michelle Tanz a Wlderness Stewardship Fellow for the National Forest Service. The initial observation was that the 2 km bushwhack around Blanca Lake has gotten much brushier as the alpine meadow becomes more sub-alpine. Columbia Glacier is a low elevation avalanche fed glacier that developed a new lake at its terminus a decade ago that continues to expand. The east side of the glacier has been thinning much faster than the west side altering the very shape of the glacier. Observed snowpack in 2020 was below average except for on the slopes of the main west side avalanche fans. The upper basin at 1550-1650 m averaged 2.2 m of snowpack at the 70 probing locations, which is 70% of normal. This snowpack will not survive the melt season. Terminus retreat has been 217 m since our first observation in 1984.

Claire Giordano working on painting of Lower Curits Glacier and Mt. Shusksan (Mariama Dryak Photograph).

Jill Pelto completes sketch, while sitting on ice chunk, of Easton Glacier icefall (Mariama Dryak Photograph).

Cal Waichler annotated story board style sketches both capture and explain the scene at Columbia Glacier (Mariama Dryak Photograph).

Sholes Glacier had the highest percentage of surface blue ice of the glaciers observed. Snowpack had been reduced from at a rate of 8 cm/day during the first week of August, a relatively warm period. A snow cave at the terminus could be entered from a terminus crevasse that was 50 m long, 10 m wide and 2-5 m high. This is indicative of a relatively stagnant rapidly retreating terminus. From 2014-2020 the glacier has retreated m, which is equivalent to the retreat from 1990-2014.

On Easton Glacier the terminus slope was the gentlest we had seen in our 31 years of consecutive observations. The terminus has retreated 430 m in this period. The significant thinning in the last few years had both reduced crevassing in the lowest icefall, but had reduced crevasse depth. Jill Pelto has been observing the crevasses depth in all the open crevasses in this icefall over the last decade. The biggest change has been from 2018-2020 with average depth being reduced by 40%. Snowpack on the bench at 2000 m averaged 2.4 m at the 45 observation sites, which is 75% of normal. The snowpack remained below normal at 2200 m, before a sharp increase to above normal snowpack averageing 5.1 m in 14 crevasse observations at ~2500 m. At this same elevation retained snowpack, now firn from previous years averaged 2.25 m. Based on the storm stratigraphy the big difference seemed to be the result of an atmospheric river precipitation event of 12+ cm from 1/31-2/2, that led to a snow depth decline and snow water equivalent decline at the Middle Fork Nooksack Snotel at 1550 m, while above 2300 m this all fell as snow. The freezing levels were above 2000 m for much of the event. The better high elevation snowpack will help Easton Glacier’s mass balance in 2020.

Easton Camp from adjacent to 1990 terminus position (Jill Pelto Photograph).

Hochstetter Ice Cap Loses All Snowcover in 2020, Franz Josef Land

On August 27, 2020April 24, 2024 By mspeltoIn climate change glacier retreat

Landsat images from 1999, 2015 and 2020 of Hochstetter ice Cap. Snowcover=100% in 1999, 80% in 2015 and 0% in 2020.

Hochstetter Ice Cap covers most of Hocstetter Island (Ostrov Khokhshtettera) in the the southern part of the Franz Josef Land archipelago. Situated ~1000 km from the North Pole this area is known for its white ice caps and cold summer temperature averaging 2 C. The lack of sea ice in the region is exposing the marine margins of the ice caps in Franz Josef Land to enhanced melting. This has and will lead to more coastal changes and island separations (Ziaja and Ostafin, 2019), such as occurred on Hall and Littow Island. Here we examine Landsat imagery from 1999-2020 to reveal changing snowcover. The summer of 2020 featured record low sea ice in the Barents Sea by mid July (NSIDC, 2020), due to the Siberian heat wave this past spring which led to early ice retreat along the Russian coast.

In early August 1999 the island is mostly surrounded by sea ice and the ice cap is fully snowcovered. In July 2000 and 2002 the situation is similar with insignificant exposed ice. At the end of July 2015 the island is mostly surrounded by sea ice, while the island is largely snowcovered there are meltwater saturated blue areas on the ice cap. On August 2, 2020 there is no snowcover on the ice cap and very limited sea ice around the island. Three weeks later on August 22, 2020 the ice cap remains bare of snowcover and is hardly the bright white that the area is known for. This period of extensive ice exposure leads to significant ablation of the exposed darker and older glacier ice leading to a large mass balance loss and glacier thinning.

Hochstetter Ice Cap in early August 2020 has lost all of its snowcover and has little sea ice in the vicinity. The blue coloration to the ice cap indicates meltwater is present.

Landsat images from 2002 and 2020 of Hochstetter ice Cap. Snowcover=100% in 2000 and 0% in 2020.

Mendeleevbreen/Øydebreen, Svalbard Terminus Retreat and Snowline Rise

On August 16, 2020April 24, 2024 By mspeltoIn svalbard glacier retreat

Øydebreen (O) and Mendeleevbreen (M) in 2002 and 2020 Landsat images. Red arrow is the 1990/2002 terminus, yellow arrow the 2020 terminus and purple dots the snowline.

Øydebreen and Mendeleevbreen are a pair of glaciers in Sørkapp Land, Svalbard that a share a divide. Mendeleevbreen flows north to Hornsund and Øydebreen south to Isbutka, meeting at the ice divide at 300 m. The Institute of Geophysics Polish Academy have maintained a Polish Research Station in Hornsund since 1957. The 1984 map, from the University of Silesia, of the glaciers and geomorphology document the extent of the glaciers in 1983 in the region indicating Mendeleevbreen being connected beyond the northern end of its fjord to its neighbor to the east Svalisbreen. A detailed examination by Blaszczyk, Jania and Kolondra (2013) reported the total area of the glacier cover lost in Hornsund Fjord area from 1899–2010 was approximately 172 km². The average glacier area retreat increased from a mean of 1.6 km²/year to 3 km²/year since 2000. Pelto (2017) reported significant retreat of all 10 major tidewater glaciers of Hornsund Fjord. In the August 4, 2020 image it is apparent that one could walk from the terminus of the Mendeleevbreen over the divide to the terminus of the Øydebreen without encountering snow.

In 1990 the distance from the front of Mendeleevbreen to Øydebreen was ~17.5 km. Øydebreen terminated just east of Fallknatten, a rib of rock separating the glacier from Vasilievbreen. Mendeleevbreen terminates adjacent to a tributary from the east Signybreen. The snowline in the 1990 August Landsat image is at 200 m. By 2002 Øydebreen has retreated substantially across its entire front. Jania et al (2006) noted a 400 m advance of the center of Mendeleevbreen from 1990 to 2004. The east margin retreated and the west margin was stable during this period, with the overall front position advancing ~100 m. The glacier is known to have surged in the past, and this could have been a small surge event. The snowline in the August 2002 Landsat image is at 225 m. By 2014 the distance from the front of Mendeleevbreen to Øydebreen was 13.5 km. The Mendeleevbreen terminus had retreated to the eastern tributary of Grobreen. The snowline in August 2014 is at ~225 m. The snowline in August 2015 is at ~200 m.

By August 2020 the distance from the front of Mendeleevbreen to Øydebreen was 12.5 km, a combined retreat of 5 km since 1990. Øydebreen is now poised to retreat into its own fjord. The snowline at the start of August 2020 is above the 300-m ice divide, leaving the possibility that no snow at all will remain by the end of the melt season on either glacier. It was noted in early July how high the snowline was on Svalbard glaciers. The retreat of these two glaciers fits the pattern of Svalisbreen, Samrarinbreen and Vasilievbreen. Unfortunately the high snowlines of 2020 indicate large mass losses will occur that will only accentuate ice loss.

Øydebreen (O) and Mendeleevbreen (M) in 1990 and 2020 Landsat images. Red arrow is the 1990/2002 terminus, yellow arrow the 2020 terminus and purple dots the snowline.

Øydebreen (O) and Mendeleevbreen (M) in 2014 and 2015 Landsat images. Red arrow is the 1990/2002 terminus, yellow arrow the 2020 terminus and purple dots the snowline.