Mount Baker Glacier’s Perspective on Climate Change 1984-2022-Disastrous!

On July 26, 2023April 19, 2024 By mspeltoIn North Cascade Glaciers4 Comments

Camp above Coleman Glacier on Heliotrope Ridge, (Jill Pelto painting)

Mount Baker is the most glaciated peak and highest mountain in the North Cascade Range at 3286 m. The Nooksack Indian Tribe refers to this strato volcano as Komo Kulshan, the great white (smoking) watcher. Mount Baker has 12 significant glaciers that covered 42 km² in 1984 and ranged in elevation from 1320 m to 3250 m. Kulshan watches over the Nooksack River Watershed, and its flanks are principal water sources for all three branches of this river and Baker River. In 1984 we began an annual monitoring program of glacier mass balance, terminus position and glacier area on these glaciers. Over the last 40 years we have visited these glaciers every summer observing their response to climate change.

In 1984/85 we visited 11 of the 12 glaciers mapping their terminus position. All but one had advanced between 1950 and 1975 emplacing an advance moraine. In the 1980’s as each glacier retreated from this moraine we used these prominent moraines as a benchmarks, as their ice cores have melted and erosion has occurred they have become less prominent. The distance from the typically well preserved, fresh moraines to the current glacier front has been measured in each case using a laser ranging device with an accuracy of +1m. In 2009 Mount Baker glacier had declined to 38.5 km² Pelto and Brown (2012). The Randolph Glacier Inventory reported a glacier area of 37 km² in 2015. In October 2022 an updated area was determined for Mount Baker glaciers at 33.5 km². This represents a decline of 20% in 38 years. Pelto and Brown (2012) identified a mean annual mass balance loss of -0.52 m/year from 1990-2010 on Mount Baker glaciers. From 2013-2021 the mass loss had more than doubled to -1.30 m/year. Below we review each glacier circling the mountain counter-clockwise

Measurement of glacier retreat from the advanced moraines ~1979 to 2022. We have measured terminus position of these glacier on 130 occassions from 1984-2022.

Easton Glacier from our survey camp in (2022) above and 2003 (below) illustrating 470 m retreat from 1990-2022.

Change at terminus from August 2022 to August 2023. Image from same location though different orientation area the size of a hockey rink lost all of its ice here.

Crevasse measurement of annual snowpack at 2500 m on Easton Glacier comparison of 2019-2022.

Easton Glacier flows down the south side of the mountain and feeds the Baker Lake Hydropower project. We have monitored the mass balance and terminus change of this glacier every year from 1990-2022. This is a World Glacier Monitoring Service reference glacier. In recent years thinning has exposed a few bedrock knobs near 2200 m on the glacier. The glacier has lost 21 m w.e. since 1990 driving a 470 m retreat during this interval. The pace of loss and retreat has been faster since 2013. The typical snowpack retained at the end of the summer has declined from 2.6 to 1.2 m w.e. at 2300 m.

Deming Glacier icefall indicating velocity locations and change in terminus from 1979.

The Deming Glacier drains the southwest side of the summit of Mount Baker a stratovolcano in the North Cascades of Washington, with a massive icefall feeding the lower valley terminus reach of the glacier. The icefall begins at 2200 meters and descends to 1600 meters. The glacier feeds the Middle Fork Nooksack River which provides water supply to Bellingham, WA. Deming Glacier flows from the summit and is the headwaters of the Middle Fork Nooksack River. We observed the terminus of this glacier every year from a survey point and conduct snow depth measurements at 2200 m on the glacier. he NASA Measures ITS_LIVE application uses feature tracking to determine glacier velocity. An examination of velocity change from the top of the icefall to the bottom on Deming Glacier from 2015-2022 indicates deceleration at the three points within or below the icefall, but no change at the top of the icefall. At the top of the icefall red X velocity has declined ~20%. In the middle of the icefall, green X, velocity has also declined ~20% since 2017. Near the base of the icefall, orange X, velocity has a chaotic signal lacking a clear trend. Below the icefall at the blue X, velocity has declined by ~20-30%. The resulting reduction in flux to the terminus will continue the rapid retreat. Pelto and Brown (2012) measured a 360 m retreat of Deming Glacier from 1979-2009, ~20 m/year. From 1979-2021 the glacier has retreated 725 m, with the rate of retreat from 2009-2021 of ~30 m/year.

Coleman Glacier and Roosevelt Glacier terminus at their maximum size in 1979, photo from Austin Post. Each has receded above the first prominent icefall step indicated by extensive crevassing.

Coleman and Roosevelt Glacier in 2014

In 1984 Coleman Glacier had just completed its advance begun in 1948. The Roosevelt Glacier on left almost merged with it and Coleman stretched across the Glacier Creek in the valley bottom leaving a prominent moraine that we surveyed retreat from. The Coleman Glacier has retreated 200 m upslope from Glacier Creek by 1997. Retreat has accelerated with 675 m of retreat from the 1979 moraine to 2022. In 2019 we surveyed the same line across the glacier at 1800 m that we had examined in 1988 and found the glacier had thinned by 38 m in this area.

Coleman Glacier Terminus in 2022.

Roosevelt Glacier retreating to top of bedrock step in 2019.

Roosevelt Glacier is adjacent to Coleman Glaier on the northwest side of Mount Baker. It has followed the same pattern as the Coleman Glacier with less total retreat since 1979 of 550 m. The glacier in 2022 has retreated above a large bedrock step and has a thin profile that will encourage ongoing rapid retreat.

Mazama Glacier in 2015

Looking up Mazama Glacier from near the saddle with Rainbow Glacier at 2000 m.

Mazama Glacier flows from the summit down the north side of Mount Baker. The glacier terminates at the head of Wells Creek at 1470 meters. This is a glacier we visit briefly each summer since 1984, but is not a focus of detailed observations. The glacier had a low slope relatively stagnant tongue in 1988 that has led to a rapid retreat of 825 m by 2022. The glacier has a high snow algae region near the Dorr Steamfield.

Sholes Glacier terminus in 2015 with stream gaging location, we calibrated this stream discharge station for the Nooksack Indian Tribe.

Sholes Glacier terminus in 2022 with 1984 terminus location indicated.

Sholes Glacier is on a ridge extending northeast from Mount Baker. We have surveyed mass balance on this glacier each year since 1990. In 2012 in a joint project with the Nooksack Indian Tribe we began summer long monitoring of streamflow below this glacier that has identified the response of glacier melt to heat waves (Pelto et al 2022). The glacier has lost 24.6 m w.e. thickness since 1990 and retreated 170 m, most of that retreat since 2010. Our studies of streamflow indicate how during heat waves glaciers in this basin increase discharge by ~20% and limit water temperature increases (Pelto et al 2022).

**Rainbow Glacier terminus in 2014 indicating the 2o14 and 1984 position. Taken by Tom Hammond from Rainbow Ridge.**

**Rainbow Glacier annual accumulaiton layer thickness in 2013.**

Rainbow Glacier is a World Glacier Monitoring Service reference glacier that we have measured the mass balance of each year since 1984.The glacier begins at 2200 m at a saddle with Mazama and Park Glacier and drains the northeast flank of Mount Baker into the headwaters of Rainbow Ceeek and then Baker Lake. The glacier has lost 17.7 m w.e thickness which has driven a retreat of 700 m. The glacier was advancing during our first two years of observations. At the 2000 m saddle with Mazama Glacier the accumulation zone has persisted. The average retained snowpack has declined from 2.7 m to 1.5 m.

Park Glacier Cliffs in 2003

Park Glacier drains the northeast side of Mount Baker’s summit area, meltwater flowing into Baker Lake. Each year we work on the adjacent Rainbow Glacier and during the 1980’s and 1990’s the Park Glacier Cliffs provided a daily sequence of avalanches, the noise echoing across the valleys. By 2010 this occurrence was rare, as the cliffs receded and diminished in height. This accompanied the retreat of the main valley tongue that most of these avalanches had fallen onto. By 2022 the glacier has receded 690 m from the advance moraine of the 1970’s

Boulder Glacier in 1993 from just below its 1970s advance moraine.

Boulder Glacier from our camp in 2003 illustrating retreat

Debris covered terminus of Boulder Glacier, due to subglacial debris exiting onto glacier surface

Boulder Glacier drains the east side of Mount Baker into Boulder Creek and then Baker Lake. The glacier was advancing rapidly in the 1950s. Our second visit in 1988 revealed a significant retreat underway. The terminus area of the glacier is debris covered due to subglacial debris flows from the crater exiting onto the glacier surface. This glacier has retreated 850 m retreat from its advance moraine of the 1970’s.

Talum Glacier in 1979 image from Austin Post

Talum Glacier has a wider bottom then top, as it is pinched between the Boulder and Squak Glacier on the east flank of Mount Baker. There are several terminus tongues, which tends to reduce the rate of retreat. Retreat from the advance moraines to 2022 has been 380 m.

Squak Glacier from survey camp in 1990

Squak Glacier from survey camp in 2009

Squak Glacier is adjacent to Easton Glacier on the southeast slope of Mount Baker. This glaciers retreat has been 420 m since 1984 when it was still in contact with its advance moraine. There are several bedrock areas emerging in what was the accumulation zone of the glacier, indicating a substantial expansion of the ablation zone. Thinning of the glacier from 1990-2009 is evident with expansion of ridge between Squak and Talum.

In 2023 we will again be on Mount Baker assessing the ongoing rapid response to climate warming generating glacier thinning and retreat.

Mount Baker Glaciers, Washington Snowpack Recession and Evolution May 2022-May 2023

On May 16, 2023April 19, 2024 By mspeltoIn North Cascade Glaciers1 Comment

Sholes Glacier snowcover extent change from 8-8-2022 to 10-17-2022. Snowcover declined from 98% of glacier to 10% of glacier during this period. Black dots are measurement sites, yellow dots the transient snowline, purple contour= 1.5 m, green contour= 2 m, brown contour= 2.5 m, and orange contour= 3 m snow depths on 8-8-2022.

The 2022 melt season for Moutn Baker glaciers was one for the record books, with a slow start and a prolonged intense melt lasting into Late October. Peak snowpack was not reached until May 20, 2022 at the Lyman Lake (1515 m) and Middle Fork Nooksack (1825 m) Snotel sites, with limited melt before June 1. These two sites have the highest correlation with our glacier mass balance observations (Pelto, 2018). Peak snowpack at Paradise, Mount Rainier (1565 m) was reached on May 26. The snowpack on June 1 at LL and MFN was 1.45 m Snow Water Equivalent (SWE) and 1.40 m SWE respectively. Snowpack at LL melted completely on July 14 and at MFN on July 11, with an average daily loss of 3.2 cm/day SWE. From June 1-Oct. 19 when the melt season ended, observed melt exceeded the previous highest years, we have observed during the 1984-2022 period. In 2023 peak snowpack was reached in mid-April at both LL and MFN, with rapid melt reducing snowpack during the first half of May.

Lyman Lake and Midde Fork Nooksack Snotel site snowpack depth in cm SWE observations beginning April 1 in 2022 and 2023. In 2022 May was a period of snowpack increase in 2022, while the first half of May 2023 has resulted in rapid snowpack depletion.

Heather Meadows snowpack depth (inches) at 1300 m, with 2022 rising above average during late April, while 2023 dips to average by the start of May.

On Sholes Glacier on August 6th-8th, 2022 we observed snow depths at 110 locations with an average snow depth of 2.25 m, 1.35 m SWE. We also checked two ablation stakes emplaced on June 1 indicating 3.55 m of snow melt, 2.1 m SWE. Sentinel images from Aug.8, Aug. 30, Sept. 9, Sept 27 and Oct. 17 reveal the recession of the snowline through the observation network allowing identification of snow ablation during these intervals. On Aug. 8, 98% of the glacier was snowcovered. On Aug 30, this had declined to 55%, with the snowline intersecting regions of the glacier that had 1.1 m SWE of snow cover on Aug. 8. By Sept. 9, the glacier was 40% snowcovered. On Sept. 27 the glacier was 25% snowcovered, with the snowline interseting sites that had 1.9 m SWE on Aug. 8. This is usually approximately the end of significant melt. However, in 2022 summer conditions continued through Oct. 19. The glacier was 10% snowcovered on Oct. 17, with the snowline intersecting sites that had 2.7 m SWE on Aug. 8.

The total observed snow melt for the June 1-Oct. 17 period was 4.8 m SWE on Sholes Glacier, eclipsing the previous June-end of melt season highs in 2015 of 4.0 m and in 2021 of 4.4 m. In both of those years the melt season did not extend into October, though May had significant melt. The Sholes Glacier did not suffer as much mass loss, because the initial snowpack was significantly greater in 2022. To have an equilibrium mass balance a glacier typically requires 55-65% of its area be snowcovered at the end of the melt season. A 10% snowcover indicates substantial mass losses.

On Rainbow Glacier on Mount Baker observations of snow depth on Aug 5-6, 2022 identified snow depths across the glacier. By Oct. 17th the areas of the glacier with 3.8 m or less of snowpack in early August had lost snowcover, indicating ablation of 2.4 m SWE of snowpack after early August. There was an area of exceptional snow algae at ~2100 m downwind of Dorr Steamfield on Rainbow Glacier, that Alia Khan’s Western Washington University research group examined. We led them through the Rainbow Icefall to this location.

On Easton Glacier, Mount Baker at 2500 m on Aug. 10th there was 5.25 m of snow remaining, compared to 2.75 m on September 27. At 2100 m there was 2.6 m of snowpack on August 10th with this snowpack melting completely between Sept,. 22 and Sept. 27. Indicating 1.6 m SWE of ablation during this period.

What 2022 illustrated is that a good winter season of accumulation, followed by a delayed melt season start, still cannot offset the persistent extended heat the region has experienced the last two summers. With the melt season off to a faster start in 2023 the outlook for Mount Baker glaciers is for another significant mass loss.

Snow depths on Rainbow Glacier on Aug 5-6, 2022.

Snow algae on Rainbow Glacier at 2100 m on Aug. 5th. Alia Khan’s WWU collecting samples.

Contrasting snow depth in crevasse in mid-August of 2020 and 2022 at 2500 m on Easton Glacier. Snow depths remaining on August 10, 2022 was ~5.25 m in 2022.

Snow depth at 2100 m on Aug 10th, 2022 on Easton Glacier

Sholes Glacier, WA and a Cascade of Ologies

On October 12, 2021April 22, 2024 By mspeltoIn climate change glacier retreat, glaciers salmon, North Cascade Glaciers

Watercolor painting of Sholes Glacier. The small figure is at the current terminus of the glacier, and the photo that inspired this painting was taken from where the glacier used to end about 35 years prior. By Jill Pelto

Sholes Glacier is on the northeast flank of Mount Baker, WA. We have spent the last 32 years completing detailed measurments on this glacier that has revealed a story of glacier mass balance loss, thinning, retreat, declining area, and a cascade of other consequences impacting other “ologies” beyond the glacier. If you are intrigued by many ologies, the Podcast by Allie Ward will be inspiring as it was to this title.

Sholes Glacier and stream gage station. We have constructed a rating curve for this station, that the Nooksack Indian Tribe maintains (Grah and Beaulieu, 2013).

The climatology of the region has shifted, with one key change being more frequent and intense heat waves. Glaciers and heat waves just are not compatible. Using daily maximum temperatures for the 1981-2021 period for Mount Baker from ERA5 temperature reanalysis, completed by Tom Matthews at Loughborough University, indicates that there have been 83 days where the maximum temperature exceeded 12°C, an average of 2 days/year. In the last five years there have been 22 days exceeding 12°C, over 4 days/year. There have been 16 days during 1981-2021 period when the maximum temperature exceeded 14°C, 75% (12) of these have been in the last five years.

Probing snow depth on Sholes Glacier in 2014, this is completed annually at a fixed network of over 100 locations.

In terms of glaciology the result of the climate shift is that the glacier has lost 25-30% of its volume from 1990-2021. The terminus has retreated 155 m while the area has decreased by 25%. The changes have been most rapid in the last 8 years. The two years of largest mass loss were 2015 and 2021. We measure both melting (ablation) on the glacier and runoff from the glacier. This combination allows determination of the amount of glacier runoff. During 24 heat waves in the region from 2009-2021 mean daily ablation during the heat waves has ranged from 4.5-7.2 cm w.e./day (w.e.=water equivalent). The highest rate of 7.2 cm was during the June 26-July 1, 2021 period.

Sholes Glacier in 2015 exhibiting the darkening of the surface that occurs in high melt years, increasing melt rates. How much black carbon and algae is part of this darkening is the research of Alia Khan (WWU).

For a glacier to be in equilibrium or have a positive mass balance the majority of the glacier must be in the accumulation zone, snow covered at the end of the summer, that is an accumulation are ratio (AAR) greater than 50%. Pelto and Brown (2012) noted that for Mount Baker an AAR of 60% is required for a break even balance for the year. From 2013-2021 the average accumulation area ratio has been 35%. For Sholes Glacier if 50% of the glacier is exposed ice and firn in early August that increases mass loss. The ice and firn for the same weather conditions have a 30-40% higher melt rate than the snowpack. An early season heat wave strips the snow off earlier exposing the darker faster melting glacier surfaces for longer further increasing mass loss, note image above.

Sholes Glacier in 2021. The glacier has retreated 170 m from 1990-2021, the terminus in 1990 is approximately whre the goats are crossing the stream.

Hydrology downstream in Wells Creek and the North Fork Nooksack River is changing in part because of the changes in glacier runoff. Glacier runoff is a major source of streamflow during the summer low-flow season and mitigates both low flow and high water temperatures (Pelto, 2015). This is particularly true during summer heat waves, but this ability has been diminishing in the region (Moore et al 2020) For the last 37 summers we have been in the field monitoring North Cascade glaciers response to climate change including during heat waves (Pelto, 2018). In the last decade we have made synchronous observations of glacier ablation and stream discharge immediately below Sholes Glacier, Mount Baker (Pelto, 2015). This in conjunction with observed daily discharge and temperature data from the USGS stations on the ~6% glaciated North Fork Nooksack River (NFN) and the unglaciated South Fork Nooksack River (SFN), contrasts and quantifies the ameliorating role of glacier runoff on discharge and water temperature during 24 late summer heat wave events.

**Measuring discharge below Sholes Glacier in 2016.**

Sholes Glacier and ablation measurements on Sholes Glacier indicate daily ablation ranging from 5-6 cm/day, which for the NFN currently yields 9-11 cubic meters/second. This is 40-50% of the August mean discharge of 24 cubic meters/second, despite glaciers only covering 6% of the watershed. In the unglaciated SFN warm weather events generated a mean stream temperature change of +2°C, only 1 event in the NFN generated this rise and the mean was +0.7°C. Durng the June 2021 heatwave from June 21-29 maxium daily stream temperature in SFN warmed 3°C, vs 0.8°C for NFN. This illustrates that a greater proportion of snowmelt, which NFN recieves, has limited the temperature rise. Discharge rose at least 10% in 20 of the 24 events in the NFN with an average increase of 24%. In the SFN all 24 events led to a decreased discharge with an average decrease of 20%. The primary response to these summer heat waes is increased discharge in the heavily glaciated NFN, and increased stream temperature in the unglaciated SFN.

Discharge change during heat waves in South Fork (decreases) and North Fork Nooksack River (increases) above. Below temperature change during heat waves in South Fork (significant rise) and North Fork Nooksack River (small rise).

Glacier runoff is a product of glacier area and melt rate. Overall glacier runoff declines when area reductions exceed, ablation rate increases. This has already occurred in the NFN and now glacier runoff is declining (Pelto, 2015). The measured ablation rate is applied to glaciers across the NFN watershed, providing daily glacier runoff discharge to the North Fork Nooksack River. For the NFN glacier runoff production was equivalent to 34% of the total discharge during the 24 later summer heat wave events. As the glaciers continue to retreat the NFN will have a declining mitigation of heat waves for discharge and temperature and trend towards the the highly sensitive SFN where warm weather leads to declining streamflow and warming temperatures.

Aquatic ecology in glaciated watershed in turn is impacted. Glaciers are important in maintaining sufficient discharge and stream temperature that are critical for salmon in the North Fork Nooksack. Some cold-water trout and salmon species are already constrained by warm water temperatures and additional warming will result in net habitat loss (Isaak et al 2012). In the Fraser River and Thompson River, BC fish community thresholds were obsrved for mean weekly average temperatures of about 12°C and again above 19°C (Parkinson et al 2015). Below 12°C the community were characterized by bull trout and some cold water species, between 12°C and 19°C by salmonids and sculpins and above 19°C by minnows and some cold water salmonids (Parkinson et al 2015). These thresholds indicated small temperature changes can be expected to drive substantial changes in fish communities. During the 24 warm weather events noted in the North Fork only two events exceeded 12°C, while in the South Fork 15 of the events exceeded 19°C. This suggest that both rivers are near a threshold that could alter the fish community.

In the North Fork Nooksack the number of returning chinook is divided into natural and hatchery spawned salmon. The Chum and Coho salmon data for the Nooksack River during the 1999-2013 interval indicate there are two salmon population peaks for each species. The early peak is in 2002 and the second peak occurs in 2010 (Washington Dept. Fish & Wildlife, 2020). Overall numbers have not sustained an increase and remain endangered.

Ice Worm counts as the sunsets, 110 worms per square meter.

The climatology and glaciology has been difficult for ice wormology On the glacier itself ice worm population density surveys conducted annually indicate the density of ice worms has decreased since 2000 and that even 10 m beyond the edge of the glacier on snowpack they do not exist. This combined with the reduction in glacier area indicate population decline of ice worms.

In 2009 we observed the largest goat herd 62 goats (13 kids), some of them seen here below Sholes Glacier.

The climatology has been more favorable in terms of Goatology.We have conducted annual mountain goat surveys in the Ptarmigan Ridge-Sholes Glacier region each years since 1984. Populations stayed steady from 1984-2000, before rising dramatically through 2010. The difficult winters of 2011 and 2012 reduced the population, followed by a recovery up to 2021.

Three year running mean of mountain goat census conducted each summer while we are working on Ptarmigan Ridge, Sholes Glacier and Rainbow Glacier.

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.

Art and Science on the Easton Glacier: Reflections from the NCGCP 2020 Field Season

On March 30, 2021April 23, 2024 By mspeltoIn North Cascade Glaciers

The field team at Camp discussing science communication and gazing at the Easton Glacier. Photo by Jill Pelto

By: Cal Waichler, Jill Pelto, and Mariama Dryak.

It is the evening of Aug. 9th, 2020 and six of us are camped near the terminus of Easton Glacier. The sun has dropped below the moraine ridge above camp and a chilly breeze has forced us to put on layers. We are enjoying dinner cooked on our camp stoves, discussing what we observed on the ice today. The toll of climate change on Easton Glacier, on the southern flank of Mount Baker, is impossible to escape. We are here to both measure this change and communicate what it means.

Within our team of six, four of us are trained as scientists, and all of us highly value creative science communication. This passion can manifest as art (painting, printmaking, sketching), writing, podcasting, blogging or video-making. We all appreciate that exercising creativity with others can provide us with a unique context for communicating about glaciers and climate change.

**Cal creates at Columbia Glacier–sketching and taking notes to capture the power of our lunch spot that day. Photo by Mariama Dryak.**

**Jill paints the icefall. Photo by Mariama Dryak.** .

The Easton Glacier is large and stretches up to 2950 m elevation. We are here to monitor its health for the 31st consecutive year: its snow coverage, snow depth, terminus retreat, change in surface profile, and its annual mass balance (snow gain vs. snow loss). Easton Glacier is one of the forty-two World Glacier Monitoring Service reference glaciers, meaning it has 30+ consecutive year of mass balance observations, qualifying it for this select group. To learn more about this glacier over time, check out https://glaciers.nichols.edu/easton/ and a previous Easton Glacier update.

While we are at Easton Glacier to measure annual changes, we also see this landscape in the realm of both art and science. From the artistic lens we may note the same things that we do during research: the debris covering the retreating terminus, the crevasses melting down and getting shallower. But we also notice the beauty of these structures, how the crevasse patterns splay out across a knob, and the parallel lines preserved on a serac – recording five years of accumulation like rings on a tree. Observation is a theme in both art and science. We train our eyes to notice things in different ways, to pay attention to certain details. We are able to document these changes in our field notebooks, but also in sketchbooks, journals, photos, and videos.

The records of beauty stored in our sketchbooks serve as a qualitative reminder of what this landscape looks and feels like. In the process of depicting the landscape at the end of a field day, we paint our joy and exhaustion onto the page. In the moment, this act uncovers more details and allows us to reflect. Weeks later when we are off the mountain, we reopen our water-logged, dirt-streaked pages and are taken back to that place where we were. Field sketches, poems and paintings help us capture the emotion of moving through and attempting to understand sublime spaces. They are a vital link between our memories and sharing the meaning of our experience with others. They are also a deliberate recording of time and place — a kind of data in their own right.

The experience of working in this environment is memorable to us — we get to observe a plethora of crevasses, dozens of meltstreams, and strikingly beautiful colors. We can feel a range of excited, inspired, and nervous emotions throughout the day. For us, this experience is giving us the emotional context to our research: being present we can understand that “why”. That reason why the work matters not just for scientific knowledge, or the local ecosystem, but also for humanity. The science results alone can share the data that underlies that, but they might not always connect with other people in a way that elicits that comprehension. Our creative communication through writing and art can elicit that deeper, emotional understanding of why it’s important to preserve and protect these places, and why we need to understand the amount of change that will occur to the climate and ecosystem. Our collection of art shares stories about Easton Glacier in ways that connect with the science, and also go beyond it.

This summer we all felt especially fortunate to be in the North Cascades. Covid-19 has kept us all so isolated and often indoors. The chance to work on the glaciers and live at their feet for two weeks gave us back some of the breathing room we lacked in 2020 – a lucky opportunity indeed.

Cal’s Art – clairewaichler.com

Mariama’s website – Let’s Do Something Big

Jill’s Art – jillpelto.com

34th Annual, 2017 North Cascade Glacier Climate Project Field Season

On October 3, 2017April 28, 2024 By mspeltoIn North Cascade Glaciers1 Comment

2017 Field Season Video

For the thirty fourth consecutive summer we headed into the field to monitor the continued response of North Cascade glaciers to climate change. In 1984 when I began this program we selected 10 key glaciers to monitor. Two of these have now disappeared. All the glaciers have retreated extensively and lost considerable volume. The mass balance loss is 19 m of water equivalent thickness, which is over 20 m of ice thickness loss on glaciers that averaged less than 75 m thick. This is significant with 25-30% of their entire volume lost. This project continues to monitor glacier loss and the runoff they provide. We also complete an annual inventory of ice worms on Sholes Glacier and mountain goats on Ptarmigan Ridge region. In 2017 our key project was a continue partnership with the Nooksack Indian Tribe monitoring glacier melt and runoff in the North Fork Nooksack River basin. We have not yet had the chance to determine the daily glacier discharge and the resultant contribution to the North Fork Nooksack River. The dry conditions of August certainly will lead to many days with more than 40% of the flow coming from glacier melt as was the case in 2015.

The snowpack on April 1st snowpack was 110% of normal, by June 1st, the snowpack was trending down steeply, but
remained well above the last four years and similar to 2012. Summer turned out to be the driest on record in Seattle and

tied for the warmest for the June 21-Sept. 22nd period (KOMONews). In the mountains the overall melt season temperatures for May 1 through Sept. 30th was 0.15 C cooler than 2015 values, due to a cooler spring. The most striking feature of the field season was the forest fire smoke largely from British Columbia that obscured views most days.

Of the glaciers observed one had a significant positive balance, one a slight positive balance-essentially equilibrium and seven had negative mass balances. The two glaciers with the most positive balance were the Sholes and Rainbow Glacier, adjacent glacier on the north side of Mount Baker. The nearby Mount Baker ski area reported 860 inches of snow in 2017, significantly above average. Compared to other locations in the range this winter snowfall was a positive anomaly, that also was observed on the nearby glaciers. The snow water equivalent in multiple crevasses on Rainbow Glacier at 2000 m in early August was 3.8-4.1 m. On both Easton and Rainbow Glacier the mass balance gradient was steeper than usual. On Rainbow Glacier the mass balance was -3 m at 1500 m, 0 at 1700 m and +2.5 m at 200 m as summer ended. We also observed terminus retreat on every glacier. Retreat averaged 12 m in 2017, lower than in 2015 or 2016. More striking than retreat in some cases is thinning that reduces slope and frontal thickness. On Lower Curtis Glacier the terminus seracs are 15 m shorter than two years ago. On Columbia Glacier the lowest 200 m of the glacier has a slope that has declined by 5 degrees in the last three years and the glacier terminus has retreated 60 m in two years.

Climate Driven Retreat of Mount Baker Glaciers and Changing Water Resources

On December 11, 2015May 2, 2024 By mspeltoIn glacier climate change, Glacier Observations, North Cascade Glaciers

We have spent 300 nights in a tent just on this mountain collecting data from 1984-2015 in this study that the book documents.

This post has the same title as a book released last month as part of the Springer Briefs in Climate Studies series. The nice thing about publishing research emerging from 30 years of field research in a book is that I had a chance to include 104 figures in 107 pages. Here I give a brief synopsis of the book and a key figure from each of the six chapters.This book presents the impact of climate change on Mount Baker glaciers, USA, and the rivers surrounding them. Glaciers are natural reservoirs that yield their resource primarily on warm dry summer days when other sources are at their lowest yield. This natural tempering of drought conditions will be reduced as they retreat. Mount Baker, a volcano in the Cascades of Washington, is currently host to 12 principal glaciers with an area of 36.8 km2. The glaciers yield 125 million cubic meters of water each summer that is a resource for salmon, irrigation and hydropower to the Nooksack River and Baker River watersheds. Recent rapid retreat of all 22 glaciers is altering the runoff from the glaciers, impacting both the discharge and temperature of the Nooksack and Baker River. Over the last 30 years we have spent 270 nights camped on the mountain conducting 10,500 observations of snow depth and melt rate on Mount Baker. This data combined with observations of terminus change, area change and glacier runoff over the same 30 years allow an unusually comprehensive story to be told of the effects of climate change to Mount Baker Glaciers and the rivers that drain them.

Chapter 1: Panchromatic sharpened Landsat image of the glacier of Mount Baker in Aug. 2014, rendered by Ben Pelto (UNBC).

We have worked on each of these glaciers except Thunder Glacier. After advancing from 1950-1979, the glaciers have all been in retreat, in 2015 the average retreat was 390 m since 1985.

Chapter 2 Comparison of Easton Glacier from our base camp in 2003 and 2015, where we have spent over 90 nights. We measure the retreat of each glacier in the field as they respond to climate change.

Chapter 3 looks at mass balance of glaciers in the area including the Sholes Glacier Daily ablation measurements over the last 30 years allow determination of a relationship between daily melt and air temperature. Other factors matter, but air temperature does yield a good relationship.

Chapter 4 Glacier runoff provides a critical water resource to the Nooksack River. We measure meltwater runoff from Sholes Glacier and observe glacier melt on several glaciers in the basin. This allows determination of the contribution of glaciers to the watershed. In 2014 contributions from glaciers exceeded 40% of total North Fork Nooksack River streamflow on 21 days after Aug. 1. This is a critical period for salmon migration in the watershed.

Chapter 5 Glacier runoff is measured below the Sholes Glacier in conjunction with Oliver Grah and Jezra Beaulieu, Nooksack Tribe. This is the record for part of the 2014 field season at the gage site.

Chapter 6 Deming Glacier in 2011 Google earth image illustrating retreat. The glacier has retreated 420 m from 1979 to 2015.

Mazama Glacier Retreat, North Cascades, Washington

On July 22, 2011January 18, 2013 By mspeltoIn Glacier Observations

Mazama Glacier flows down the north side of Mount Baker, a strato volcano in the North Cascades of Washington. The glacier begins at the summit plateau, 3260 meters, and terminates at the head of Wells Creek 1470 meters. This is a glacier we visit briefly each summer since 1984, but is not a focus of detailed observations. In 2010 we descended from its divide with Rainbow Glacier at 2100 meters to just above the terminus. In the 1970’s the USGS map (top image in sequence) indicates the terminus extended down valley to 1200 meters, this was after a period of advance for the glacier. The glacier advance 450 meters from 1950-1980 (Pelto and Hedlund, 2001). In 1987 we observed the glacier to have begun to retreat. By 1993 the glacier had retreated 200 meters. From 1993 (middle) to 2009 (bottom image) the glacier retreated an additional 750 meters. The rate of retreat has been higher for this glacier because of the loss of the low elevation debris covered terminus that had existed from the 1950’s-1990’s. The glacier is still heavily crevassed and active. The retreat will continue as indicated by thinning near the snowline of the glacier from 1993 to 2009. Note the expansion of the rock outcrop in glacier center (A) from the top image, 1993 to 2009 bottom image. There is also considerably less crevassing near Point A. Also note the stranded glacier ice at Point B and C in 2009. This loss has been due to 7 of the last 10 years having a snowline that rose above the elevation necessary for equilibrium. In 2009 at the end of the summer just 36% of the glacier was snowcovered, 65% needs to be snowcovered for equilibrium. .
In two weeks we will be visiting Mazama Glacier again. Given the heavy 2011 snowpack it is unlikely we will get to see the terminus which should be under avalanche debris.