NORTH CASCADE GLACIER CLIMATE PROJECT 2022-39th Annual Field Program

On By mspeltoIn North Cascade Glaciers

Mount Baker camp for Rainbow and Sholes Glacier (Illustration by Megan Pelto)

Science Director: Mauri S. Pelto, mspelto@nichols.edu
Art Director: Jill Pelto, pelto.jill@gmail.com

2022 Field Season: For the 39th consecutive summer we are heading into the field to measure and communicate the impact of climate change on North Cascade glaciers. We will complete detailed measurements on 10 glaciers, three of which are part of the World Glacier Monitoring Service reference glacier network (42 glaciers globally), which have 30+ consecutive years of mass balance observations.

Who we are? NCGCP was founded in 1983 to identify and communicate the response of North Cascade glaciers to regional climate change. We are a fieldwork-based project with a focus on measuring changes in mass balance, glacier runoff, and terminus behavior. The project has an interdisciplinary scope — collaborating with a range of natural scientists, artists, journalists, and conservationists. The goal of this is to best document and share our research with a broad audience. We aim to bring stories of these places and their changes to as many people as we can, making our research feel personal to more than just our team. The North Cascades glaciers are important for the ecosystem, as a water resource to Washington, and as a place of recreation for so many. By monitoring them every year, we continue to provide critical data on glacier response to climate change and informed stories of their health that reveal the impacts of our warming world.

2021 Field Team for Rainbow Glacier

Why study glaciers in the North Cascades? Glaciers are one of the world’s best climate monitors and are a critical water resource to many populated glaciated regions. This is particularly true in the North Cascades where 700 glaciers yield 200 billion gallons of summer runoff and glaciers have lost 30 % of their area in the last century.  This has reduced glacier runoff in late summer in the region as the reduction in glacier area has exceeded the increase in melt rate. During heat waves this role is even more profound with the glacier fed North Fork Nooksack River discharge rising ~24% due to greater melt, while adjacent unglaciated South Fork Nooksack River discharge declines by ~20% (Pelto et al., 2022). The increased discharge limits the rise in river temperature during heat waves to 0.7 C in the North Fork, with the South Fork increasing by 2 C. This increases stress on the salmon in the South Fork (Pelto et al., 2022).

Terminus Change at Columbia and Easton Glacier.

This field season follows the 2021 season that featured a historic heat wave at the end of June and a period of extended warm weather that lasted until Mid-August. The heat led to a greater exposure of bare ice on glaciers earlier in the summer, particularly at higher elevations.  For ice surfaces with a higher albedo and greater density the observed melt rates are 7-9 cm per day water equivalent during warm weather events vs 4-6 for snow surfaces. This led to substantial mass losses on North Cascade glaciers, -2 m.

This summer we will have an opportunity to assess the long-term ramifications of the 2021 summer and measure the response of glaciers to the weather of 2022. This winter snowpack remained below average until a late season surge from April into May. The month of May and June had below normal temperatures leading to an above average snowpack. A hot July has melted into this snowpack and we will observe how much remains on the glaciers.

Field Team 2021:

Jill Pelto is an artist and scientist from New England who grew up loving winter sports and trips to the mountains. She incorporates scientific research and data into paintings and prints to communicate environmental changes. Her multi-disciplinary work weaves visual narratives that reveal the reality of human impacts on this planet. She completed both her B.A. degrees in Studio Art and Earth and Climate Science and her M.S. focused on studying the stability of the Antarctic Ice Sheet at the University of Maine, spending two field seasons at a remote camp in the southern Transantarctic Mountains. Jill will be joining the project for her 14th field season. She is excited about continuing to document the change in North Cascade glaciers that she has witnessed each of the last ten years — through science and art.

Mauri Pelto has directed the project since its founding in 1984, spending more than 700 nights camped out adjacent to these glaciers. He is the United States representative to the World Glacier Monitoring Service, author of the AGU blog “From a Glacier’s Perspective”, and associate editor for three science journals.  He is on the Science Advisory Board for NASA’s Earth Observatory. His primary position is Associate Provost at Nichols College, where he has been a professor since 1989.

Echo Allen is a rising Junior at UC Berkeley studying Architecture and Sustainable Design. Her studies deal with urban ecology and environmental justice in relationship to physical design. Echo finds inspiration for her studies in the backcountry as a NOLS backpacking student, avid rock climber, and kayak guide. Echo is currently working with the City of Richmond and SHAC (Sustainable Housing at Cal) to design and construct an affordable and scalable model of a solar-powered off-grid capable tiny house that will be used as affordable housing in Richmond CA. She hopes to help people understand the impact of climate change and implement possible mitigation strategies through her work in outdoor education and architecture.

Ellie Hall (she/her) is a recent graduate from the University of Colorado – Boulder with a BA in Environmental Studies, a minor in Geology, and a certificate in Arctic Studies. She is interested in researching and documenting the nuanced impacts of climate change on cold regions, and especially learning more about the relationship between decreasing snowpacks and increasing wildfires. She has spent the past two summers researching these areas, interning with INSTAAR’s Arctic Rivers Project and NASA’s ABoVE Campaign. She is excited to get into the field this summer to see the theoretical knowledge she’s learned be put into practice to collect valuable data. Ella’s other interests include backcountry skiing, mountain and gravel biking, rock climbing, and water sports.

Jenna Travers (she/they) is about to start her final year as a marine biology major at the University of Oregon. Her research focuses on the impacts of glacier retreat on salmon, how communities are affected by glacier loss and salmon declines, and how climate issues are communicated to the public. They are currently working as a writer with GlacierHub and a salmon identification contractor with the Wild Salmon Center, and they have also worked as a legislative intern for the Oregon State Legislature, a Water Justice intern with a local nonprofit. In her free time, Jenna enjoys hiking, skiing, rock climbing, and playing games with her roommates.

Field Partners 2022

Alia Khan’s research team including grad students Sally Vaux and Shannon Healy focus on environmental chemistry in the cryosphere, including black carbon and snow algae to document global change of glacier and snow melt in mountainous and polar regions. Western Washington University Cryosphere Studies and Aquatic Biochemistry Lab.

Claire Giordano is an environmental artist, writer, and educator creatively telling the stories of science, climate change, and the modern experience of nature. From creating rain-dappled sketches in an old growth forest to filming a watercolor class beside a glacier, careful observation of nature inspires her goal is to connect people and place through art.  In 2021 she founded the Adventure Art Academy – a series of virtual watercolor classes filmed outside – to invite others into the joy of painting outside.

Jaclyn Baer is an artist and photographer in the PNW. She is new to the climate change artist role, but excited to learn and share. She loves painting with gouache in her studio and watercolor out in the field. Besides painting, she spends her free time hiking and backpacking with her husband Ryan.

Nooksack Indian Tribe, for the 11th consecutive year, we will be conducting field work aimed at providing field validation and streamflow calibration data below Sholes Glacier for the ongoing work of the tribe.

Crevasse Stratigraphy on Easton Glacier

 2022 Field Schedule

Jul 31:  Hike in Columbia Glacier
Aug. 1:  Columbia Glacier
Aug. 2:  Columbia Glacier
Aug. 3:  Hike Out Columbia, Hike in Ptarmigan Ridge
Aug. 4:  Sholes Glacier
Aug. 5:  Rainbow Glaciern
Aug. 6:  Rainbow Glacier
Aug.7:   Hike out, Hike in Lower Curtis Glacier
Aug. 8:  Lower Curtis Glacier
Aug. 9:  Hike out, Hike in Easton Glacier
Aug. 10: Easton Glacier
Aug. 11: Easton Glacier
Aug. 12: Hike out Easton/Hike in Daniel
Aug. 13: Ice Worm Glacier Survey
Aug. 14: Daniel and Lynch Glacier Survey
Aug. 15: Ice Worm ablation, Hike out
Aug. 16: Field season concludes

Deming Glacier Icefall Deceleration 2017-2022 Driven by Mass Balance Loss

On By mspeltoIn North Cascade Glaciers

Deming Glacier velocity from NASA MEaSUREs ITS_Live at four locations from below icefall at blue X to above icefall at red X. There is not a significant change in velocity above the icefall (red X), but significant deceleration in the icefall and below the icefall. 

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. I first observed the Deming Icefall from the terminus area of the glacier in 1987. This visit demonstrated that it is not safe to hike to the terminus of this glacier. In 1990 we began annual observation of Deming Glacier. Each summer we monitor the adjacent Easton Glacier in detail including mass balance, while also taking several specific observations of Deming Glacier including terminus position, and accumulation between 2400-2700 m. This combined with mass balance assessment on Easton Glacier provides an annual assessment of the meltwater provided by the glacier to the Nooksack River system. During heatwaves the tributaries of the Nooksack fed by glaciers have had the impacts mitigated, while those without glaciers have seen significant temperature increase and discharge decrease (Pelto et al 2022).

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. The declining mass balance is less pronounced above the icefall. The icefall transitions the glacier from the accumulation zone to the ablation (melt) zone at the bottom of the icefall. Above the icefall at 2400-2700 meters the average snow depth left at the end of the summer based on several thousand crevasse stratigraphy measurements from 1990-2013 had been 2.75 meters, from 2014-2021 the average depth has been 2.4 m.

The result of the declining mass balance of the entire glacier and the upper glacier will be glacier deceleration. The 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.

View of the Deming Glacier from terminus to top of icefall in 2019. Jill Pelto at left, Abby Hudak and Mauri Pelto at right. X’s mark the velocity locations, Point A ties this to the upper glacier view, red arrow is the 1987 terminus location.

The icefall sweeps around a bedrock with an east and a west arm splitting above and rejoining below the knob.

The Deming Glacier from the top of the icefall to the summit of Mount Baker in 2020.

In mid-August 2022 snowpack was particularly low right to the top of Deming Glacier. Comparison with 2020 which was an average year for the last decade, but still a significant mass balance loss.

Deming Glacier terminus annotated to show retreat from 2004 to 2019 in photographs from Mauri Pelto

Terminus of Deming Glacier in 2004 and 2019 illustrating the ongoing retreat of the terminus, 725 m from 1979-2021.

Jill Pelto measuring Crevasse depth and snowpack thickness in Crevasse at 2500 m on Deming Glacier.

Glacier Landslides and Collapses Preconditioned by Warming

On By mspeltoIn climate change glacier retreat10 Comments

Lamplugh Glacier, Alaska in 2015 (before) and 2016 (after) landslide in Landsat images. The Landslide covered 17 km2 of the glacier, yellow dots. B=Brady, L=Lamplugh, R=Reid Glacier.

Ice whether as permafrost, in a glacier, filling cracks or coating surfaces literally helps stabilize materials on mountain slopes. Climbers who ascend glaciated peaks have long practiced early starts to avoid the heat of the day. The goal to avoid falling, rock, ice and snow all made more prevalent by the rising temperatures of the day, which leads to thawing/weakening the ice and snow binding materials together and to the mountain. Working on steep alpine glaciers each summer for 40 years, we do not go below a steep convex icefall or terminus after the sun is on it. These approaches are a risk accommodation to short term diurnal changes. This combination of hazards has been playing itself out on the small scale altering the climbing routes from Mont Blanc to Mount Kenya and Mount Rainier generating more frequent large-scale avalanches/landslides/glacier collapses in glaciated mountain ranges.  On Mont Blanc massif Maurey et al (2019) found that 93 of 95 climbing routes had been affected by climate change, 26 greatly and 3 no longer existed.

Long term climate change also leads to preconditioning that increases opportunities for thawing/melting and weakening of the bonds between mountains and the rocks, snow and ice perched on and within their slopes. Atmosphere and ocean warming over the past century are driving rapid glacier thinning and retreat of the majority of alpine glaciers destabilizing hillslopes and increasing the frequency of landslides from unconsolidated, unstable sediments often perched on slopes. Jacquemart et al (2020) conclude that as “meltwater production increases with rising temperatures, the possible increase in frequency of glacier detachments has direct implications for risk management in glaciated regions.”

The long term preconditioning has led to a number of  large avalanches/landslides/glacier collapses from 2015-2021.  Each has a unique story, but each is connected to warming.

Leones Glacier, Chile sequence of Landsat images illustrating the landslide and its evolution.

Flat Creek, AK

Flat Creek, Alaska is in the Wrangell Saint Elias National park. Jacquemart and Loso (2018) detailed a series of events from 2013-2016 generating debris flows. They identified in satellite images, that large parts of the glacier that occupied the head of Flat Creek disappeared during the August 2013 and August 2015 events. In 2013 shows that the front third of the glacier tongue went missing and in 2015, the ice in the central trough of the glacier disappeared altogether.   The combined events transported 24.4–31.3 × 106 m3 of ice and lithic material from Flat Creek Glacier (Jacquemart et al 2020), who concluded this event was triggered by unusably high meltwater input. In 2016 the event was smaller, but the resulting debris flow/slushalanche was caught on video .

Taan Fjord, AK

Taan Fjord is a newly developed fjord in Icy Bay, Alaska resulting from glacial retreat in recent decades that has exposed unstable slopes and allowed deep water to extend beneath some of those slope. The Tyndall Glacier had retreated 17 km from 1961 to 2015, stranding lose deposits of glacial sediments on the slopes (Williams and Koppes, 2020). Slope failure at the terminus of Tyndall Glacier on 17 October 2015 sent 180 million tons of rock, 60 × 106 m3  into Taan Fiord,  (Dufresne et al 2017) . The resulting tsunami reached elevations as high as 193 m.

Lamplugh Glacier, AK

Lamplugh Glacier terminates in Glacier Bay, Alaska. In 2016 Southeast Alaska had its warmest spring ever. On June 28, 2016 a landslide triggered by the collapse of a rock face occurred. After accelerating downslope the debris hit the ice on the glacier and kept sliding bulldozing snow and ice as it went. Seismic analysis, indicated a landslide of about 120 million metric tons (Morford, 2016). The Landslide covers an area of 17 km2 and is 7.5 km long on the Lamplugh Glacier (Pelto, 2016)

Eliot Creek, BC

Rapid glacier retreat set the stage for a slope failure to occur in  Eliot Creek, a steep mountain valley in the Coast Range of British Columbia on November 28, 2020, about 18 million m3 of rock descended 1000 m down the steep slop, then across the toe of a glacier before entering a 0.6 km2 glacier lake displacing water that produced a >100-m high run-up (Geertsema et al 2022). A water saturated debris flow overtopped the lake outlet and scoured a 10-km long channel before depositing a 2 km2 fan below the lake outlet. Floodwater and associated debris entered the fjord where it produced a 60+km long sediment plume and altered turbidity, water temperature, and water chemistry for weeks. The outburst flood destroyed forest and salmon spawning habitat throughout the valley (Geertsema et al 2022).

Joffre Peak, BC

Two catastrophic landslides occurred in quick succession on May 13 and 16, 2019 from the north face of Joffre Peak in the Southern Coast Mountains, British Columbia. Beginning at 2560 m and 2690 m elevation as rock avalanches each rapidly transformed into debris flows along Cerise Creek. The toe of the main debris flow deposit travelled 4 km from the origin, with debris flood materials reaching 5.9 km downstream. Photogrammetry indicates the source volume of each event is 2–3 Mm3, with combined volume of ~5 Mm3 (Freile et al 2020). The slope was pre-conditioned by progressive glacier retreat and permafrost degradation, with precursor rockfall activity noted at least ~6 months previous. The 13 May landslide followed a  rapid snowmelt, with debuttressing from the first slide triggering the 16 May event (Freile et al 2020).

Chamoli, India

Nanda Devi region glaciers in 10-16-2020 image indicating the snowline at between 5800 and 6000 m on all the glaciers in the upper Rishi Ganga: Bethartoli (B), Dakshini (D), Ramani (R), Rinti (Ri), Trisul (T), Uttar Nanda Devi (UN), Uttar Rishi (UR).

On 7 February 2021, a catastrophic mass flow descended from the steep north face of Ronti Peak and then descended the Rishiganga, and Dhauliganga valleys in Chamoli, Uttarakhand, India, causing widespread devastation and severely damaging two hydropower projects (Shugar et al 2021). This event occurred after a post-monsoon season featuring high snowlines on adjacent glaciers and the warmest January in the last six decades  in Uttarakhand, India. and warmth across the region (Pelto et al, 2021; Matthews et al, 2021). By mid October the snowline on the glaciers had risen to ~5800-6000 m on glaciers in the region which is above the landslide initiation location,  see above.  More than 200 people were killed or are missing. The~27 × 106 cubic meters of rock and glacier ice collapsed and rapidly transformed into an extraordinarily large and rapidly moving debris flow that scoured the valley walls up to 220 meters above the valley floor (Shugar et al 2021).

Aru Glacier, Tibet

A 3 km long glacier collapsed in an ice avalanche on July 17, 2016, killing nine herders living in their summer pasture at Aru Village, Xizang Autonomous Region, China (Tian et al 2016). The Aru Glacier, ranged in elevation from 5250 to 6150 m. The collapsed ice flowed/slid downslope within 4–5 min over the narrow terminus tongue and swept across the gently-sloping alluvial fan, reaching Aruco Lake. The average depth of the deposits was estimated to be 7.5 m indicating a total volume of fallen ice of at least 70 million m3, or equivalent to an average glacier thickness loss of ~21 m (Tian et al 2016). Both glaciers had a mass balance gain in years prior to the collapse.

Air temperature at the nearest state-run meteorological station had increased by ~1.5°C over the past five decades. The total precipitation in the area prior to the accident had been the highest in the 2010–16 period exceeding the average value by 88% (Tian et al 2016).The event occurred in the midst of the summer monsoon during a period of wet weather. The warm wet weather likely pre-conditioned the event. There is no evidence of a previous event at this site.(Jacquemart et al 2020) concluded this event was triggered by unusably high meltwater input.

Leones Glacier, Chile

 

Leones Glacier in March 2015, Jill Pelto Photograph

Leones Glacier is a lake terminating outlet glacier on the east side of the Northern Patagonia Icefield. In late 2014 or early 2015 a landslide spread onto the Leones Glacier from an adjacent mountain slope. My daughter Jill took this image out a plane window returning from field work in the Falkland Islands, illustrating the landslide.  Landsat images from 2014 (before) and 2015 (after) indicate the 1.5 km2 size of the landslide debris cover on the glacier. By 2020 the landslide had migrated downglacier, but there is also debris cover further upglacier suggesting an additional smaller landslide, from a bedrock ridge in an icefall area. The glacier had been thinning 1 m/year and had a high snowline averaging above 1300 m in 2013, 2014 and 2015, which would further debuttress the mountain slope (Glasser et al 2016: Pelto, 2017).

Amalia Glacier, Chile

Amalia Glacier is a rapidly thinning outlet glacier of the Southern Patagonia Icefield. A 2019 landslide from the northeast slopes of Reclus Volcano with a volume of 262 ± 77 × 106 m3  disrupted 3.5 km2 of Amalia Glacier’s surface (Van Wyck de Vries et al 2022). Retreat had debuttressed the ice marginal mountain side that failed. The glacier briefly accelerated and then decelerated after the landslide.

Santa Lucia, Chile

On December 16, 2017 a rock landslide was triggered that transitioned into a debris flow incorporating much of a glacier before destroying most of Santa Lucia killing 18 people (Duhart et al 2019). The landslide occurred following an intense rainfall event with 122 mm of rain in 24 hours and a two week period of high temperatures. The flow had a volume of 7.2 million m3 with a flow velocity of 72 km/hour.

 

Swiss Alps Exceptionally High Glacier Snowlines Mid-July 2022

On By mspeltoIn switzerland glacier retreat1 Comment

Rhone Glacier snowline at end of 2003 melt season, July 9, 2022 and July 17, 2022.

Rhone Glacier Sentinel images indicating the snowline position mid July 2021 and 2022 and mid-June 2022.

Rhone Glacier Sentinel images indicating the snowline position at the end of the melt season in 2018 and July 18, 2022. 

Rhone Glacier is a temperate valley glacier and is the primary headwaters for the Rhone River. Easy access to this glacier has resulted in terminus observations since 1880 (GLAMOS, 2021). From 1880-2020 the glacier has retreated 1575 m. The glacier experienced a minor advance from 1963-1987. From 1988-2020 retreat has been continuous totaling 520 m (GLAMOS, 2021; WGMS). This has been driven by ongoing mass balance losses, 15 consecutive years from 2007-2021, the entire period of record. Currently the glacier terminates in an expanding proglacial lake. The Glacier Monitoring in Switzerland (GLAMOS), led by Matthias Huss is the most comprehensive of any nation in the world, and their documentation of this exceptional summer of melt will be vitally important. Here we examine the snowline on the Rhone Glacier this summer compared to 2003 and 2018 the previous most extensive melt years.

In 2003 the snowline at the end of the melt season averaged 3100 m, there is a considerable area of firn above the bare ice line in the Landsat image. In 2018 the end of summer snowline averaged 3150 m. In mid-July 2021 a relatively average year the snowline is at 2800 m.  The mid-June 2022 snowline is already at 2800 m, by July 9 the snowline has reached 2950 m, rising to 3050 m by July 17 and 18 2022.  This post will be updated in one week with additional imagery illustrating the snowline position at the end of the heat wave. The rate of rise of the snowline during the recent heat waves can be used to determined ablation when the balance gradient is known (Pelto, 2011). There is relatively little firn exposed below this elevation, just bare glacier ice, because the snowline has often reached this elevation in recent years stripping the glacier down to bare glacier ice. In the six weeks as the snowline rises, there will an area of firn exposed.  The problem for the glaciers as we have seen over and over in recent summers is the loss of snowpack early in the summer, results in greater exposure of the more rapidly melted glacier ice, compared to snow (Pelto, 2022).  In the case of Haut d’Arolla Glacier and many other Austrian, French and Swiss alpine glaciers, by mid-July 2022 there is little snowpack remaining. This will increase mass loss. The increasing frequency and intensity of heat waves and their impact on glaciers has been a point of emphasis for our research.

Rhone Glacier retreat data from WGMS.

In 2003 the snowline in Landsat image is at m near the end the ablation season. On Sept. 18 2018 the snowline reached its highest elevation averaging 3100 m. On July 18 2021, the snowline on Rhone Glacier was at 2800 m, a typical elevation. On June 18, 2022 the snowline had already reached 2800 m, a month earlier than in 2021. By July 15, 2022 just as the latest heat wave was beginning the snowline had risen to an average of 2950 m.

Arolla Glacier snowline end of summer 2020 and 2021 and mid-July 2022 in Sentinel images.

Alsek Glacier, Alaska Releases its own Fireworks-Iceberg Discharge July 2022

On By mspeltoIn alaska glacier retreat

Alsek Glacier, Alaska in a Sentinel Image from July 1, 2022 indicating an area of rapid recent calving, red dots. The northern tongue has accelerated in the last six year (NASA ITS_Live).

Alsek Glacier descends from the Fairweather Range terminating in Alsek Lake on the coastal plain. The glacier terminated at Gateway Knob (G) near the outlet of Alsek River from Alsek Lake in the early part of the 20th century (Molnia, 2005). At that time it had a joint terminus with Grand Plateau Glacier. The glacier retreated 5-6 km by 1984 along the central margin from Gateway Knob. In 1960 the glacier had a single terminus joining downstream of an unnamed island in Alsek Lake, that Austin Post told me reminded him of a boats prow. This “Prow Knob” (P) much like Gateway Knob a century ago stabilizes the terminus.  Retreat from this knob will lead to an increase retreat of Alsek Glacier.  Loso et al (2021) note that retreat of Grand Plateau Glacier will change the outlet of Alsek Lake from Dry Bay to the Grand Plateau Lake. Here we examine the change from 1984-2022 with Landsat and Sentinel imagery updating Pelto (2017)

Alsek Glacier retreat from 1984-2022 in Landsat images. Red arrows mark the 1984 terminus location, yellow arrows the 2022 terminus location, pink arrows indicate tributary separation, AR=Alsek River, GP=Grand Plateau, G=Gateway Knob, A=glacier junction, B=tributary separation, C=tributary separation, D=tributary confluence.

In 1984 the terminus location is denoted with red arrows it has separated into two termini on either side of “Prow Knob”. The northern terminus tongue is located on a narrow island on the north side of Alsek Lake. The southern tongue merges with the northern arm of Grand Plateau Glacier in 1984. Two tributaries at the pink arrows merge with the main glacier. By 1999 the northern tongue has retreated from the narrow island, which exposes the terminus to enhanced calving. The southern terminus has separated from the Grand Plateau Glacier. By 2013 the northern terminus has retreated to the northern end of “Prow Knob” and the southern terminus is directly south of “Prow Knob” in a 1.8 km wide channel.  By 2018 two tributaries of Alsek Glacier are fully detached from the glacier, pink arrows. In 2018 the northern terminus tongue has retreated 3.7 km since 1984 into the 2.0 km wide channel on the northeast side of “Prow Knob”. The center of the southern terminus has retreated 2.5 km since 1984 and remains in the channel on the south side of “Prow Knob”. The length of the calving front has declined from an 8 km long calving front in 1984 to a 4 km calving front in 2018. By 2021 further retreat has led to a 2.8 km wide calving front, and a 1.6 km long contact with Prow Knob. From 1984-2022 the retreat and loss of area has been: 4.3 km and 8.6 km2 respectively for the northern terminus,  2.7 km and 5.1 km2 for the southern terminus and 7 km and 13.1 km2 for the northern arm of Grand Plateau Glacier.

In 2022 the northern terminus arm has accelerated within 1 km of the calving front, note the two red X, marking velocity locations. This has generated additional calving and rifting, that is evident in the June 28 image. The NASA ITS_LIVE velocity measurement tool uses Landsat and Sentinel images to determine velocity using feature tracking. The rifting and acceleration is producing enhanced calving and retreat. The area of enhanced calving on July 1 is 0.3 km2. The acceleration and rifting is typically an indication of a greater degree of terminus flotation that can be due to thinning and/or reduced contact with Prow Knob. This will lead to additional calving events this summer as the glacier progressively detaches from Prow Knob.

 

Alsek Glacier retreat from 1999-2013 in Landsat images. Red arrows mark the 1984 terminus location, yellow arrows the 2022 terminus location, AR=Alsek River, GP=Grand Plateau, PK=Prow Knob, G=Gateway Knob, A=glacier junction, B=tributary separation, C=tributary separation, D=tributary confluence.

Alsek Glacier retreat from 2018-2021 in Landsat images. Red arrows mark the 1984 terminus location, yellow arrows the 2022 terminus location, pink arrows indicate tributary separation, AR=Alsek River, GP=Grand Plateau, PK=Prow Knob, G=Gateway Knob, A=glacier junction, B=tributary separation, C=tributary separation, D=tributary confluence.

Sentinel images from June 2022 illustrating the development of rifting at yellow arrow, that leads to the July 1 calving event. A=glacier junction, B=tributary separation, C=tributary separation

 

Zarilang Glacier, China Retreat and Lake Expansion

On By mspeltoIn china glacier retreat

Zarilang Glacier in 1998 and 2021 Landsat images illustrating glacier retreat and lake expansion. Point A marks the junction of two tributaries.

Zarilang Glacier, China  flows north from the Bhutan border is in the Yarlung Zangbo River watershed draining the northwest flank of Kula Kangri. Yarlung Zangbo which becomes the Brahmaputra River supplies the Zangmu Dam (510 MW), online in 2015, that produces 2.5 billion kwh of electricity a year. Wang et al (2021) observe a significant increase in discharge of Yarlung Zangbo due to glacier melt and permafrost degradation.  Zhang et al (2020) observed glacier retreat leading to lake expansion averaging 20 m/year in the Himalaya for the 2008-2016 period, with Yarlung Zangbo basin having the highest average rate of lake expansion.

In 1998, Zarilang Glacier terminated in a proglacial lake that was 1.0 km long with an area of 0.24 km2, 1.8 km upglacier from the terminus was a significant junction at Point A, with a medial moraine marking the boundary extending to the terminus.  In 2001 the calving front is 400 m wide and has retreated ~100 m since 1998. By 2014 the glacier has retreated into a narrowing portion of the lake. By 2018 the medial moraine marks the eastern margin of the glacier, which means the eastern tributary is no longer reaching the lake. In 2021 the glacier has retreated 700 m and the lake is now 1.7 km long and has an area of 0.50 km2. In 2022 the calving front is 200 m wide and the glacier terminates 900 m from the junction at Point A, and the eastern tributary ends 100 m short of the lake. The lake area has doubled since 1998, which is a higher rate than the already high rate of 51% globally for glacial lakes noted by Shugar et al (2019) for glacial lakes 1990-2018.

Sun et al (2022) rated the hazard of a glacier lake outburst flood from this lake as low. The retreat is similar in scope to that of other glaciers retreating in expanding lakes in this region of China such as Sepu Kangri  and  Quiaqing Glacier. Examining glacier mass loss in the Himalaya King et al (2019) noted that lake terminating glaciers lost 30% more volume than other Himalayan glacier from.

Sentinel images in 2022 of Zarilang Glacier and the glacial lake. On May 31 there is some lake ice left. Note the medial moraine now is the eastern margin of the terminus.

Zarilang Glacier in 2001 and 2018 Landsat images illustrating glacier retreat and lake expansion. Point A marks the junction of two tributaries.

Heat Wave Leads to Rapid Glacier Snowcover Loss in Alps

On By mspeltoIn Italy glacier retreat, switzerland glacier retreat8 Comments

Grande Murailles Glacier, Italy (GM) in June Sentinel images. The yellow line is the glacier margin, the expansion of bare glacier ice from 1-3% of the glacier on June 10 to 20% of the glacier by June 18 is evident. The snowline is ~3200 m.

The heat wave during the last week that has impacted western Europe and the Alps has led to a predictable impact on glaciers (WMO, June 17, 2022). A month ago I focussed on the fact that heat waves and glaciers don’t usually go together; however, in the last several years an increasing number of heat waves have affected alpine glacier regions around the world (Pelto, 2022). In particular heat waves leave a greater portion of the glacier snow free, which enhances melting and mass balance losses. This is most pronounced when the heat wave occurs prior to or early in the melt season exposing bare glacier ice for a the bulk of the melt season.  Di Mauro and Fugazza (2022) identified an increasing melt season length and decreasing minimum albedo on glaciers in the Alp from 2000-2019, that does enhance melt. Here we utilize Sentinel 2 images from June 10 and June 18 to look at the rate of snowcover loss on three glaciers in the Alps.

On June 10 ~98% of Grande Murailles Glacier is snowcovered, 96% of Gries Glacier, and 100% of Sabbione Glacier is snowcovered. After eight days of unusual heat, the bare glacier ice regions have expanded notably, ~80% of Grande Murailles Glacier is snowcovered, 80% of Gries Glacier, and 65% of Sabbione Glacier remain snowcovered.  Grande Murailles Glacier drins west from Dent d”Herens just west of the Matterhorn. Sabbione Glacier feeds Lago del Sabbione a hydropower reservoir. Gries Glacier feeds Griessee a Hydropower reservoir. This rapid snowcover loss early in the summer is a particular issue given bare glacier ice melts ~50% faster than snowcover. This same scenario was observed last year in the Pacfic Northwest following a June Heat wave and in the Central Andes this summer 2022 after a January heat wave. In each case substantial mass balance losses occurred by summers end on these glaciers. This will continue to accelerate the fragmentation and loss of Sabbione Glaciers. This year the early season heat waves ability to strip snowcover from glaciers is enhanced by the limited snowpack that was received during the winter season that @VAW_glaciology has been reporting during spring monitoring of Swiss glaciers. This post will be updated on June 23 with additional images.

Gries Glacier, Switzerland (G) draining into the Griessee (Gs) in June 2022 Sentinel image. The terminus tongue, yellow arrow, extends below 2650 m to the terminus.

 

Sabbione Glacier, Italy (S) draining into Lago del Sabbione  (LS) in June 2022 Sentinel images. The west and south Sabbione Glacier are both entirely snowcovered on June 10. By June 18 most of the west Sabbione Glacier is bare glacier ice and 

Todd Icefield, British Columbia Retreat and Separation

On By mspeltoIn British Columbia glacier retreat

Todd Icefield in 1987 and 2020 Landsat images illustrating retreat and separation. Red arrows indicate 1987 terminus location, Point A indicates location where the glacier has separated. Point B and C are locations of expanding bedrock high on the icefield. Point D is further glacier separation.

Todd Icefield is an icefield 30 km northeast of Stewart BC at the head of Portland Canal, with Todd Glacier being the main outlet glacier draining north to Point A and Erickson Glacier draining south near Point B. Glaciers of this icefield retreated and downwasted significantly from 1974-1997, with retreat rates of 9-76 m/year (Jackson et al 2008).  Menounos et al (2019) indicate mass loss averaging -0.5 m/year from 1985-2018 in this region.

In 1987 Todd Glacier terminates in a small proglacial lake 1 km beyond a glacier junction at Point A.  At Point B and C there are small bedrock outcrops. It is also worth noting that you could hike from the end of Todd Glacier on the northside across the icefield divide to the Erickson Glacier on the south side without crossing any snowcover. By 1997 Todd Glacier has retreated from the now 0.5 km long proglacial lake, with the two glacier tributaries joining just before the terminus. Again the snowline is above the Todd Icefield divide.

In 2013, 2014, 2015, 2018 and 2019 the snowline again rose above the icefield divide, leading to continued thinning even at the divide leading to increased bedrock exposure at Point B and C in 2018-2021. By 2020 Todd Glacier has retreated m since 1987 and separated from the main tributary at Point A. In 2018-2021 it is evident that Erickson Glacier is terminating in two new expanding proglacial lakes (0.2 km2) that may merge, and Todd Glacier is also now terminating in a new proglacial lake.

Retreat of Todd Glacier has been 2.4 km from 1987-2021, which is 30-40% of it entire length. The retreat is in line with that observed at nearby Bromley Glacier and Chickamin Glacier.

Todd Icefield in 1997 and 2021 Landsat images illustrating retreat and separation. Red arrows indicate 1987 terminus location, Point A indicates location where the glacier has separated. Point B and C are locations of expanding bedrock high on the icefield. Point D is further glacier separation.

Todd Icefield in 2018 and 2019 Sentinel images, note the dirty ice extends across the icefield divide in both years, yellow arrows indicate proglacial lakes developing.

Hayesbreen, Svalbard Retreat Generating Separation

On By mspeltoIn svalbard glacier retreat

Hayesbreen (HB), Heuglinbreen (HE) and Konigsbergbreen (KB) terminating in Mohnbutka (M) in 2002 and 2021 Landsat imagery. Retreat to Point E, and reduction in connection at Point B is evident and distance from Point A to the terminus. 

Hayesbreen, Heuglinbreen and Konigsbergbreen merge forming a single tidewater front in Mohnbutka on the east coast of Svalbard. Here we examine the retreat of this glacier system and ongoing separation of Hayesbreen and Heuglinbreen with Landsat imagery from 2002-2021. Blaszczyk et al’s (2009) identified 163 Svalbard tidewater glaciers with the total length calving ice−cliffs at 860 km for the 2001-2006 period. They observed that 14 glaciers had retreated from the ocean to the land over the last 30–40 year period. They noted that Hayesbreen was retreating 20-40 m per year in 2003-2005 and had a 4 km long ice cliff terminating in Mohnbutka. They noted the glacier last surged i 1901. Sevestre et al (2018) documented two mechanisms that help generate terminus initiated surges, tidewater retreat from a pinning point and/or crevasses allowing meltwater rainwater to access the bed.  the terminus zone near Point 1.

In 2002 the prominent lateral moraines of Hayesbreen extended 5 km from Point A to the terminus. The glacier margin adjacent to Point B was 2.75 km to the terminus junction of Hayesbreen and Heuglingbreeen. By 2015 there was only 1.2 km of ice between Point B and the terminus, while from Point A to the margin was 3 km. The snowline in 2020 reached between 400-450 m near the ice divide on Heuglinbreen and close to the top of Konigsbergbreen. Hayesbreen extends above 800 m and still had an extensive accumulation area. By August 2021 the now disconnected lateral moraines from the upper glacier extend 2 km from Point A to the terminus, and there is just 0.6 km of ice connecting Heuglinbreen to Hayesbreen. The center of the glacier front has retreated 2.25 km since 2002. Mohnbutka has expanded as the glaciers have retreated. The ice connection between Heuglinbreen and Hayesbreen has narrowed from 3 km to 0.6 km during the period. This is similar to the separation at Strongbreen.

Sevestre et al (2018) noted a distinctive crevasse development pattern of terminus initiated surge progression, “Upward migration of the surge coincided with stepwise expansion of the crevasse field”, for specific observed recent surges in Svalbard. There is no evidence of this process at Hayesbreen during the last 20 years as it retreats and separates.

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Map of the region fro TopoSvalbard, and August 8, 2021 Sentinel image illustrating the limited connection between Hayesbreen and Heuglinbreen.

Hayesbreen (HB), Heuglinbreen (HE) and Konigsbergbreen (KB) terminating in Mohnbutka in 2015 and 2020 Landsat imagery. The narrowing ice connection at Point B and reduction in glacier extending beyond Point A is evident. The high snowline in 2020 exposes considerable ablation area

Grand Pacific Glacier Losing its Grand and Pacific Connection

On By mspeltoIn alaska glacier retreat

Grand Pacific Glacier in 1984 and 1999 Landsat images. Red arrow indicates the front of the clean ice flow of the Grand Pacific that also marks its lateral boundary with Ferris Glacier.  B and C indicate locations where tributary tongues have been retreating from the main glacier. M is the Margerie Glacier.

Grand Pacific Glacier in 2015 and 2021 Landsat images. Red arrow indicates the front of the clean ice flow of the Grand Pacific that also marks its lateral boundary with Ferris Glacier and the front of its active ice. Yellow arrow indicates outlet stream that is now beginning to separate the glaciers. B and C indicate locations where tributary tongues have been retreating from the main glacier. M is the Margerie Glacier.

The Grand Pacific joins with Ferris Glacier before ending at the head of Tarr Inlet in a ~1.9 km wide glacier front and 20-50 m high ice front. William Field observed the glacier advancing steadily from the 1930’s-1968 at 35 m/year , extending ~.0.5 km across the US/Canada boundary.  This advance continued behind its protective shoaling moraine/outwash plain until it was 1.5-1.6 km across the national boundary and just meeting the Margerie Glacier. A slow recession of 200 m has occurred since, with the current terminus having a width of 1.8 km, most in shallow water or terminating on a tidal flat. The Grand Pacific Glacier has been thinning for more than 50 years, which is leading to the recession, though not nearly as significant at for Melbern Glacier which it shares a divide with. Clague and Evans (1993) noted a 7 km retreat of Melbern Glacier from 1970-1987, and a 5.25 km retreat from 1986-2013 (Pelto, 2011-2017). The mass loss of the Grand Pacific Glacier system is part of the 75 Gt annual loss of Alaskan glaciers that make this region the largest alpine glacier contributor to sea level rise  from 1984-2013 (Larsen et al 2015).

William Field reported that Grand Pacific Glacier comprised 80% of the joint glacier front with Ferris Glacier in 1941, declining to 40% in 1964.  In 1984 Landsat imagery illustrates that the Grand Pacific is still supplying ice to the glacier front but only comprises 25% of the ice front. In 1999 this has diminished to 20% of the ice front, that is now entirely on an outwash plain above the tidal level.  Tributary C has disconnected from Grand Pacific Glacier between 1984 and 1999, and tributary B has retreated substantially from the Grand Pacific. By 2015 the junction of the Ferris and Grand Pacific Glacier indicates all flow of the latter is diverted east along the Ferris margin and does not reach the ice front. There is a band of clean glacier ice that reaches the junction in 2015 and in the 2016 Sentinel image, but no longer reaches the eastern margin. In 2016 the glacier outlet stream along the west side of the Grand Pacific goes under the glacier to the east margin near the junction. By 2018 the surface exposed section of the stream extends ~700 m across the Grand Pacific Glacier before going beneath the glacier along the Ferris/Grand Pacific margin. In 2021 the glacier outlet stream cuts halfway across the glacier before going beneath and emerges prior to reaching the east margin, note yellow arrows below on the Sentinel image . The clean ice area no longer reaches the junction with the Ferris Glacier in 2021. The rapid expansion of the surficial outlet stream that is physically separating the two glacier will continue to cut across the entire width of the Grand Pacific Glacier. This glacier no longer has a connection to the Pacific Ocean, and no longer presents a grand front. The retreat is limited in distance compared to Grand Plateau or Fingers Glacier, but the separation is dramatic.

Sentinel 2 image of Grand Pacific Glacier in July 2016, yellow arrow indicates glacier outlet stream beginning to transect glacier. 

Sentinel 2 image of Grand Pacific Glacier in August 2018, yellow arrow indicates glacier outlet stream expanding across glacier. 

Sentinel 2 image of Grand Pacific Glacier in July 2016, yellow arrow indicates glacier outlet stream nearly transecting the entire width of the Grand Pacific Glacier front/margin with Ferris Glacier.

 

 

 

 

 

 

Lake Fork Knik River Headwater Glaciers, Alaska Retreat, Separation and Lake Expansion

On By mspeltoIn alaska glacier retreat

Glaciers in the Lake Fork Knik River watershed  in 1986 and 2021 Landsat images. LG=Lake George Glacier and WO=Whiteout Glacier with the remainder unnamed, labelled here as W=West, NW=Northwest and SE=Southeast. Red arrows mark 1986 terminus locations and yellow dots the 2021 terminus locations.

At the headwaters of the Lake Fork of the Knik River are a series of glaciers undergoing retreat and separation. The headwaters is dominated by the Lake George Glacier, which had terminated in the large proglacial Lake George that periodically drained past/beneath Knik Glacier (Stone, 1963), after 1966 the lake no longer filled (Post and Mayo, 1971). A new smaller proglacial lake began to form due to the retreat of Lake George Glacier by. Here we examine the changes in this headwater glacier group from 1986-2021 with Landsat imagery. The proglacial lake at the terminus of Lake George Glacier is moraine dammed and has expanded from 1986-2021, this is representative of the expansion of moraine dammed lakes in Alaska with an 87% areal increase from 1984-2019 noted by Rick et al (2022).

In 1986 Lake George Glacier terminated in a small proglacial lake with an area of 0.3k m2,. Whiteout Glacier terminated at 300 m, within 3 km of LG. West and Northwest Glacier had a joint terminus (Point J) at 600 m, with two outlet streams O1 and O2. Southeast Glacier had a single terminus at 500 m and had an area of 18.4 km2,.  In 2002 the main change was the separation of West and Northwest Glacier. The snowline on LG was at 900 m in August 2002. By 2019 Southeast Glacier has two separate termini, with the ridge just north of SE dividing the glacier, with the snowline at 1100 m in August. The proglacial lake at the end of Lake George had an area of 4.0 km2,. By 2021 the proglacial lake had expanded to an area of 4.3 km2,, a 4.0 km2, increase since 1986.  Terminus retreat has been  2100 m for Lake George Glacier 1100 m for Whiteout Glacier, 1250 m for West Glacier,  1000 m for Northwest Glacier and 1100 m for Southeast Glacier. Southeast Glacier now has an area of 12 km2, a 33% area loss since 1986, ~1% per year.  In 2021 the Outlet Stream from W, NW, and SE glacier parallels the margin of Lake George Glacier, but no longer goes under or is in contact.  A notch at Point A has developed, from a meltwater runoff channel. Icebergs occupy much of the lake in 2021 indicating there is still active development of the lake.  The lake development and separation of glaciers is similar to that observed at Field Glacier, Sheridan Glacier and Excelsior Glacier.

Glaciers in the Lake Fork Knik River watershed  in 2002 and 2019 Landsat images. LG=Lake George Glacier with the remainder unnamed, labelled here as W=West, NW=Northwest and SE=Southeast. O1 and O2 are the  outlet streams of the W and NW Glacier in 1986, with O2 abandoned by 2002. 

Glaciers in the Lake Fork Knik River watershed  in August 29, 2021 Landsat image. LG=Lake George Glacier  and WO=Whiteout Glacier, with the remainder unnamed, labelled here as W=West, NW=Northwest and SE=Southeast. O1 is the outlet streams of the W and NW Glacier, yellow dots at right indicate the course. Note the notch in Lake George glacier at Point A. 

Sollipulli Volcano Glacier Recession Snow Cover Deficit

On By mspeltoIn chile glacier melt, chile glacier retreat

Landsat images of Sollipulli from 1986 and 2022. Point A-D are locations where the glacier spilled out of the caldera in 1986, but no longer does so in 2022.

Nevados de Sollipulli is a volcano, is in the central Andes of Chile near the border with Argentina in Parque Nacional Villarica, Chile. The 4 km wide summit caldera at ~2100 m is filled by a glacier. The volcano is dormant last producing lava flows 700 years ago and last erupting 2900 years ago (NASA, 2017). Reinthaler et al (2019) identified a 27% decline in glacier area from 1986-2015 on 59 volcanoes in the Andes. The study included Sollipulli where the area declined from 16.2 km2 in 1986, 20 12.5 km2 in 1999 and 11.1 km2 in 2015 (Reinthaler et al 2019). Here we examine Landsat imagery illustrating the recession from 1986-2022 and the loss of all snowcover for most of the summer of 2022. The summer of 2022 led to early summer loss of most/all the snowpack on Central Andes glaciers from 30-40 S. (Pelto, 2022)

In 1986 a Landsat 5 image illustrates that the glacier not only fills but overflows the caldera at Points A-D, with Point A and B feeding significant glacier area. The glacier is also almost completely snowcovered in late February. In 2003 the glacier is still spilling over at Point A, and is almost entirely snowcovered in mid-February. On January 8, 2022 the glacier is already 95% free of snowcover with some snow patches on the NW margin. By January 24 the glacier is 99% snow free and remains snow free through mid-March in a Landsat and Sentinel image from 3-13 and 3-16 respectively. There is a small patch of relict glacier ice near Point B, while the former glacier at Point A has disappeared. The annual layering preserved in the glacier ice as seen in the Landsat Band 5 image will continue to evolve as the glacier thins.  The dirty nature of this ice enhances solar radiation melting, particularly compared to snowcover.  Two months of exposure at the 2100 m elevation ice cap will have led to several meters of ice loss. The extent of the glacier has declined to 10.2 km2 in March 2022 a 37% decline since 1986.

Landsat images indicating the near complete snowcover in Landsat 7 image from 2003 and the loss of all snowcover that continued from January until at least March 13 2022. Note the annual layers preserved in the glacier ice now exposed at the surface.

Sollipulli Glacier in early January with only a fringing area of snowpack along the northwest margin. Sixty-four days later the glacier is still bare of snowpack.