A Tale of Two Glaciers Columbia and Easton Glacier 2021

On August 22, 2021April 22, 2024 By mspeltoIn North Cascade Glaciers2 Comments

Terminus of Columbia Glacier on left with 1984 terminus location noted. Observe the avalanche fans (A) and the relatively high snowcover on 8-2-2021. At right is Easton Glacier on 8-11-2021 with the location of the 1990 terminus indicated, 440 m of retreat to the 2021 terminus position. The glacier has only 38% snowcover at this time, which is better illustrated below.

Columbia and Easton Glacier in the North Cascade Range of Washington are two of the reference glaciers for the World Glacier Monitoring Service. We have monitored their mass balance in the field for 38 and 32 years consecutively. This year Ashley Parks, Sally Vaux, Jill Pelto and I worked on all of the glaciers with Abby Hudak, Rose McAdoo and Ben Pelto joining us for either Easton or Columbia Glacier. In 2021 a combination of an above average winter snowfall and a record summer melt has led to a different story of mass balance for the two glaciers. At Mount Baker and Stevens Pass winter snowpack on May 1 was 116% and 115% of normal (NWAC, 2021). From June 1-Aug. 17 the mean average temperature is similar to 1958 and 2015, and well above every other year. With the maximum temperature exceeding 80 F on 17 days during this period at Stevens Pass ( 3950 ft, 1200 m), each of those days represents exceptional melt conditions. Our observations indicate 11-14 cm of snowpack melt on glacier during exceptionally warm days like this. Just the melt from these 17 days would equate to half of the average summer melt for a North Cascade glacier (Pelto, 2018). The earlier summer heat wave has led to exposure of greater higher albedo and faster melting glacier ice, which is why such a heat wave is more impactful than in late summer.

Columbia Glacier occupies a deep cirque above Blanca Lake ranging in altitude from 1400 meters to 1700 meters. Kyes, Monte Cristo and Columbia Peak surround the glacier with summits 700 meters above the glacier. The glacier is the beneficiary of heavy orographic lifting over the surrounding peaks, and heavy avalanching off the same peaks. Standing on the glacier is a bit like being in the bottom of a bath tub, with avalanche slopes extending up both sides, predominantly on the west side. The last half of January 2021 was a dry period in the region, with an extensive crust forming on the snowpack. This was followed by 106 inches of dry snowfall from Feb. 4 to Feb. 20,and then 34 inches of wet snowfall and even rain through Feb. 24 This generated extreme avalanche danger and numerous climax avalanches in the Stevens Pass region.

NWAC’s avalanche forecast on 2/20 for Stevens Pass indicated that, “We haven’t seen rain above 3,500ft or so since mid-January, so one of the main concerns is that slabs 5-10′ feet thick may begin to come crashing down. The avalanche cycle(s) may last through the day Monday. In any case, very large storm slabs and wet loose avalanches are expected to continue to run from steep slopes through Monday as our once beautiful cold, dry snow becomes overloaded by wet, heavy rain and snow.”

The avalanche slopes with many pockets above Columbia Glacier in Aug. 2020, one fan can be seen bottom center. These have to filled each winter season before slides occur, in 2020 avalanching was limited.

As we headed up onto Columbia Glacier on Aug. 1, 2021 we noted a significant number of large avalanches had descended near and onto the glacier. The glacier was 87% snowcovered, including the terminus area. This is well above the recent early August average. As is the case every year we measure snow pack depth in a grid across the entire glacier. Snow depth in the three biggest west side avalanche fans averaged 4.9 m, 25% above normal. The three largest fans comprise an area of 0.14 km², yielding a volume of 686, 000 m³ swe. The melt season ends in another month, however, due to this substantial avalanching that will keep this section of the glacier covered in snow, Columbia Glacier will have a small-moderate negative mass balance.

Ashley Parks, Jill Pelto and Sally Vaux measuring snow depth in the Columbia Glacier avalanche fans.

The three primary avalanche fans each had a slope of 23 degrees. Here we are spaced out at 50 m intervals mapping the size of the fan.

Easton Glacier on the south flank of Mount Baker does not recieve avalanche accumulation, and the regions above 2500 m, typically have significant wind scouring, that leads to little increase in mass balance with elevation above this elevation on the upper glacier. There are both basins where snow is preferetially deposited by wind and convex regions where snowpack is scoured. In 2021 enroute to the glacier terminus we observed considerable stunted alpine vegetation, that emerged and then did not grow. This was prevalent on rocky slopes that were exposed during the heat wave. The example below is of Lupine with the growth from last year now brown and flat indicating the stunted size this year.

Stunted Lupine, each patch is typically 20-30 cm high and equally broad. Here the plants are 3-5 cm high.

On Aug. 11, 2021, the glacier had only 38% snowcover, with more than 50% of the area above 2500 m having lost all winter 2021 snowcover. By summer’s end the glacier will certainly have the lowest percentage of snowcover of any year since we began monitoring in 1990. The bench at 2000 m typically has 2.75 m of snowpack on Aug. 10, and this year was 50% bare, with an average depth of 0.25 m. The icefall above also lacked snowcover as well. There are a number of pockets/basins, where wind deposition increased snow depth and this snowpack will be retained.

The observations across the range illustrated that glaciers or areas of glaciers that do not have enhanced deposition from wind drifting or avalanching are either bare already or will be by the end of August. The full extent of the loss on Columbia and Easton Glacier from this summer will be evident in a month. What is apparent is that the losses from Easton Glacier will be extraordinary. More frequent heat waves continue to plague alpine glaciers, these can even occur in winter such as on Mount Everest in January 2021 (Pelto et al. 2021)

View of the lack of snowcover in the icefall at 2000-2300 m on Easton Glacier. The lack of snowcover above this point is also evident in the upper image.

Rose McAdoo and Jill Pelto measuring the 2021 snowpack at 2350 m is alareay thinner than the 2020 or 2019 retained snowpack and will be gone by the end of the month.

In 2021, I am in front of the same serac as in 2020, down slope. The average retained accumulation at this 2600 m location in the laterally extensive layers is 2-2.2 m. This year there will no retained accumulation.

Ben and Jill Pelto amongst the seracs where snowpack should be extensive, but in 2021 they are standing on 2020 firn.

Easton Glacier, Mount Baker, WA Annual Retreat & Mass Loss 1990-2017

On March 15, 2018April 28, 2024 By mspeltoIn North Cascade Glaciers

Mass balance, terminus and supra glacial stream assessment are illustrated in the video, Filmed by Mauri Pelto, Jill Pelto, Melanie Gajewski, with music from Scott Powers.

This is the story of the annual monitoring of Easton Glacier, Washington. We have been monitoring Easton Glacier on Mount Baker, a stratovolcano in the North Cascade Range, Washington since 1990. Each year we survey the terminus position, measure its mass balance, assess crevasse depths and map surface elevation on a transect across the glacier. In 1990 Easton Glacier was in contact with an advance moraine built from the late 1950’s- 1980’s. The advance moraine is noted in the 2015 Washington DNR Lidar image of the terminus area by black arrows. The green arrows indicate the recessional moraine from the winter of 2015. Red arrows indicate the Little Ice Age lateral moraines Railroad Grade (RG) to the west and Metcalfe Moraine (MM) to the east. From 1990-2017 the glacier has retreated 370 m, including 65 m in the last three years. The second Lidar image indicates the transect where the surface elevation is mapped, red line. This is close to 2000 m in elevation, and in a good snow year retains snowpack and in most recent years has lost its snowpack (note paired image below). In 2015 the worst year, the snowpack had been lost by the end of July. Note the comparison of the 2017 transect snowpack and 2015 lack of snowpack.

Washington DNR Lidar image of Easton Glacier , black arrows indicate 1980’s advance moraine, green arrows 2015 winter moraine and red arrows the Little Ice Age lateral moraines. Blue dots indicate the glacier margin.

Washington DNR Lidar image of Easton Glacier. Blue dots indicate the glacier margin. Red line the cross glacier profile.

A view along the cross glacier profile at 2000 m in early August of 2015, snowpack gone already and in 2017 with 2 m of snowpack remaining.

More than 5000 measurements of snow depth and melt have been completed illustrating the glacier has lost 16.6 m of water equivalent thickness, over 18 m of thickness from 1990-2016. For a glacier that averaged 70 m in thickness in 1990 this is ~25% of the volume of the glacier gone. The glacier has not maintained sufficient snow cover at the end of the summer to have a positive mass balance, this is the accumulation area ratio. The mass balance and terminus data is reported annually to the World Glacier Monitoring Service. The area lost in the terminus region due to the retreat has been 0.22 km2.

The glacier has also slowed its movement as it has thinned, evidenced by a reduction in number of crevasses. In the lowest icefall Jill Pelto has surveyed the crevasse depths finding a mean depth 20 m and a maximum depth of 32 m. This glacier supplies runoff to Baker Lake and its associated hydropower projects. Our annual measurements here and on Rainbow Glacier and Lower Curtis Glacier in the same watershed provide a direct assessment of the contribution of glaciers to Baker Lake. The glacier is also adjacent to Deming Glacier, which supplies water to Bellingham, WA. The Deming is too difficult to access, and we use the Easton Glacier to understand timing and magnitude of glacier runoff from Deming Glacier. Deming Glacier has retreated a greater distance during this period, 705 m, but has lost a similar area.

Annual terminus survey in 2015 terminus exposed to melting by early July. In 2017 terminus being exposed first week in August. Taken from same location.

Crevasses measurement in lower icefall and on the cross profile. In both cases crevasse depth is measured, on the profile 2017 winter snow depth remaining measured.

Easton Terminus viewed from our benchmark location just beyond 1980’s margin. Tree in foreground is over 50 years old.

Conducting Long Term Annual Glacier Monitoring

On June 29, 2016May 2, 2024 By mspeltoIn climate change glacier retreat, glacier climate change, North Cascade Glaciers

Easton Glacier in 1990, 2003 and 2015 from same location. Below Painting by Jill Pelto of crevasse assessment using a camline.

This is the story of how you develop and conduct a long term glacier monitoring program. We have been monitoring the annual mass balance of Easton Glacier on Mount Baker, a stratovolcano in the North Cascade Range, Washington since 1990. This is one of nine glaciers we are continuing to monitor, seven of which have a 32 year long record. The initial exploration done in the pre-internet days required visiting libraries to look at topographic maps and buying a guide book to trails for the area. This was followed by actual letters, not much email then, to climbers who had explored the glacier in the past, for old photographs. Armed with photographs and maps we then determined where to locate base camp and how to access the glacier. The first year is always a test to make sure logistically you can reach enough of the glacier to actually complete the mass balance work with a sufficiently representative network of measurement sites. The second test is if you can stand the access hike, campsite, and glacier navigation, to do this every year for decades; if the answer is no, move on. That was the case on Boulder Glacier, also on Mount Baker: poor trail conditions and savage bugs, were the primary issue. Next we return to the glacier at the same time each year, completing the same measurements each year averaging 210 measurements of snow depth or snow melt annually. This occurs whether it is gorgeous and sunny, hot, cold, snowy, rainy, or recently on this glacier dealing with thunderstorms. You wake up, have your oatmeal and coffee/cider/tea, and get to work. Lunch on the snow features bagels, dried fruit, and trail mix. Happy hour features tang or hot chocolate depending on the weather. It is then couscous, rice, pasta or quinoa for dinner, with some added dried vegetable or avocado. The sun goes behind a mountain ridge and temperatures fall, and the tent is the haven until the sun returns. Repeat this 130 times on this glacier and you have a 25 year record. During this period the glacier has lost 16.1 m of water equivalent thickness, almost 18 m of thickness. For a glacier that averaged 70 m in thickness this is nearly 25% of the volume of the glacier gone. The glacier has not maintained sufficient snow cover at the end of the summer to have a positive balance, this is the accumulation area ratio, note below. The glacier has retreated 315 m from 1990-2015. This data is reported annually to the World Glacier Monitoring Service. The glacier has also slowed its movement as it has thinned, evidenced by a reduction in number of crevasses. During this time we have collaborated with researchers examining the ice worms, soil microbes/chemistry, and weather conditions on the ice. This glacier supplies runoff to Baker Lake and its associated hydropower projects. Our annual measurements here and on Rainbow Glacier and Lower Curtis Glacier in the same watershed provide a direct assessment of the contribution of glaciers to Baker Lake. The glacier is adjacent to Deming Glacier, which supplies water to Bellingham, WA. The Deming is too difficult to access, and we use the Easton Glacier to understand timing and magnitude of glacier runoff from Deming Glacier.

The glacier terminates at an elevation of 1650 m, but thinning and marginal retreat extends much higher. A few areas of bedrock have begun to emerge from beneath the ice as high as 2200 m. The changes in ice thickness are minor above 2500 m, indicating this glacier can retreat to a new equilibrium point with current climate.

Mass balance, terminus and supra glacial stream assessment are illustrated in the video, Filmed by Mauri Pelto, Jill Pelto, Melanie Gajewski, with music from Scott Powers.

Mass balance Map in 2010 of Easton Glacier used in the field for reference in following years.

Accumulation Area Ratio/Mass balance relationship for Easton Glacier

Easton Glacier Assessment, Washington

On July 14, 2012 By mspeltoIn Glacier Observations1 Comment

In August we will be making a detailed study of the Easton Glacier for the 23rd consecutive summer. Our main focus is measurement of snow depth and snow melt on the glacier. We will be mapping the terminus position and two profiles of the surface elevation across the glaciers at 1800 m and 1950 m. We will also examine two new bedrock knobs that have melted out in the midst of the glacier at 2050 m. The Easton Glacier is important as a water resource for the Baker lake and Baker River Hydropower system. This hydropower system is capable of producing 170 MW of power. The runoff from Easton Glacier would normally flow into the Baker River below Upper Baker Dam, however it is extracted from the normal stream and routed through a pipeline to enter Baker Lake and then produce power via Upper Baker Dam (second image), note yellow dots showing runoff pathway. The Easton Glacier retreated over 2 km from its Little Ice Age maximum to 1955. By 1965 the glacier was advancing, this advance ended in the early 1980’s and by 1987 retreat from the moraine was evident. Beginning in 1990 we have made an annual survey of the glacier terminus noting a retreat of 320 m from 1987-2010. The first image below is of Easton Glacier from 1912 the second from 2011 with the same locations highlighted. A prominent knob on the upper glacier has changed little, ocher arrow. The lower margin of the glacier on either side of the main Easton at the blue arrow and red arrow show substantial thinning and retreat. The purple arrow indicates the terminus change. The lower Easton Glacier has changed a great deal in the last 100 years, not the upper glacier. This is an indication of a glacier adjusting to climate change that is retaining an accumulation and can survive. The last image in the sequence indicates the Little Ice Age terminus yellow line, the 1993 terminus orange, 1998 terminus is purple, 2004 terminus is green and 2009 terminus is ochre.
In the above image the red arrows indicate the location of the two survey profiles we complete across the glacier. The green arrows indicate two locations of investigation for the summer, to the left is the top of the Deming Glacier Icefall that will visit and the right green arrow a new bedrock knob that emerged from beneath the glacier in 2009. A month from now we will be surveying the glacier covering the glacier top to bottom and side to side. We will be joned by Peter Sinclair who is going to use is videography skills to examine how we measure glacier change. The first image below is from Steph Abegg a superb climber and photographer who was with us in 2010 as part of Team Juicebox working on the Uncertain Ice documentary. The main goal of our research each year is assessing the glacier’s mass balance. This is the equivalent of its bank account, with snow accumulation being deposits and snow-ice melt being withdraws. We map the changes across the glacier and determine if the bank account grew or declined, 2011 map is below. Since 1990 the bank account has lost 10 meters of thickness of an average of 70 m total. Last year the glacier did gain over a meter. A key measure is the percent of the glacier in the accumulation zone (AAR), below 65% is a loss above a gain, bottom image. The 2012 winter was a La Nina which tends to lead to very good snowpack, the transition out of La Nina took place in late spring-early summer leading to greater melting than 2011, we will see in three weeks.