36th Annual North Cascade Glacier Climate Project Field Season Begins

On July 29, 2019April 25, 2024 By mspeltoIn North Cascade Glaciers

Fieldwork includes terminus surveys, glacier runoff measurement and mass balance measurements

Field Season Begins August 1

Who we are? The North Cascade Glacier Climate Project (NCGCP) was founded in 1983 to identify the response of North Cascade glaciers to regional climate change, particularly changes in mass balance, glacier runoff and terminus behavior. This was prompted by the National Academy of Sciences listing this as a high priority and a personal appeal from Stephen Schneider. NCGCP is a field project that has a broader interdisciplinary scope and is the most extensive glacier mass balance field program in the United States. Two of the 41 reference glaciers in the world are in our network, and as of next year that will become three glaciers. We do this research cost effectively relying on no permanent camps, helicopter support or salary for the director. The field season includes no days off and each day is spent completing measurements on glaciers. The focus is on glacier mapping, mass balance measurement, terminus observations and glacier runoff monitoring. Each year we utilize several field assistants to complete the annual glacier surveys, with 2019 being the 36th field season. Our goal in choosing assistants is not to pick the most experienced, but the individuals who are capable and can benefit the most. We are a self-contained unit. Recently Hakai Magazine described our process well.

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 since 1980. These glaciers have lost 25-30% of their volume during the course of our study, three of our primary study glaciers have disappeared. We also monitor ice worms and mountain goats since we are in the same locations at the same time each year.

2019 Outlook: For North Cascade glaciers the accumulation season provides that layer of snow, that must then last through the melt season. A thin layer sets the glaciers up for a mass balance loss, much like a bear with a limited fat layer would lose more mass than ideal during hibernation. The 2019 winter season in the North Cascade Range, Washington has been unusual. On April 1 the retained snow water equivalent in snowpack across the range at the six long SNOTEL sites is 0.72 m, which is ~70% of average. This is the fifth lowest since 1984. The unusual part is that freezing levels were well above normal in January, in the 95% percentile at 1532 m, then were the lowest level, 372 m of any February since the freezing level record began in 1948. March returned to above normal freezing levels. As is typical periods of cold weather in the regions are associated with reduced snowfall in the mountains and more snowfall at low elevations. In the Seattle metropolitan area February was the snowiest month in 50 years, 0.51 m of snow fell, but in the North Cascades snowfall in the month was well below average. From Feb. 1 to April 1, snowpack SWE at Lyman Lake, the SNOTEL site closest to a North Cascade glacier, usually increases from 0.99 m to 1.47 m, this year SWE increased from 0.83 m to 1.01 m during this period. The melt season from May-Mid-July has also been warmer than average. This combination will lead to significant glacier mass loss in 2019, in one month we will report back on our measurements that will indicate just how negative.

2019 Field Team:

Clara Deck: is an earth scientist from Chicago with a passion for science communication, education, and outreach. She completed a B.A. in geology at the College of Wooster in Wooster, Ohio, where she began a journey in climatological research which led to a love for the cryosphere. In the summer of 2018, Clara contributed to glacial field work in the eastern Alaska Range, and was fascinated by the dynamic day-to-day changes in glacial features she was tasked with measuring. At the University of Maine, she is wrapping up her M.S. focused on numerical modeling of Antarctic ice shelf instabilities, but Clara’s favorite part of her college career has been sharing science with students as a teaching assistant. During her first visit to the North Cascades, she is excited to learn about ongoing glacial change and to explore accessible ways to share the findings with public audiences.

Abby Hudak is a native Floridian that has always had a deep calling to the mountains and frozen landscapes. Her passions revolve around understanding our changing climate and natural world which led her to attain a B.S. in Biological Sciences from the University of Central Florida. After starting her M.S. in Biological Sciences at Washington State University, she immediately indulged in snow sports and mountaineering in the Cascade Range. The beauty and vulnerability of these landscapes have driven her to expand her research interests to understanding aspects of the changing cryosphere. She is eager to intertwine her love for the Cascade Range and her desire to pursue scientific questions pertaining to climate impacts on alpine glaciers by working with the North Cascade Glacier Climate Project this summer.

Ann Hill, ever since she was a young child growing up in Minneapolis, Ann has been fascinated by ice and snow, however it wasn’t until her Sophomore year studying Geosciences at Skidmore College that she realized she could study ice as a career path. Consequently, during her junior year she traveled to Svalbard to gain hands-on experience studying and exploring glaciers. Determined to learn more, Ann spent a summer with the Juneau Icefield Research Program, which exposed her to glaciers that looked and behaved differently. In the fall, Ann will begin her M.S. in Earth and Climate Sciences at the University of Maine. Ann is thrilled to study the North Cascade glaciers to understand how their movement and characteristics compare to those she previously observed in Svalbard and Alaska.

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 Sciences and her M.S. focused on studying the stability of the Antarctic Ice Sheet at the University of Maine. She spent two field seasons at a remote camp in the southern Transantarctic Mountains to map glacial deposits and collect samples from them for dating. Jill will be joining the project for her 11th 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. His primary job is Dean of Academic Affairs at Nichols College, where he has been a professor since 1989.

Schedule

Aug. 1: Arrive Hike into Easton Glacier

Aug. 2: Easton Glacier survey

Aug. 3: Easton Glacier survey

Aug. 4: Hike out Hike in Lower Curtis Glacier

Aug. 5: Lower Curtis Glacier Survey

Aug. 6: Hike out Lower Curtis Glacier Hike in Ptarmigan Ridge

Aug. 7: Sholes Glacier

Aug. 8: Rainbow Glacier

Aug. 9: Hike out- Coleman Glacier survey

Aug. 10: Hike in Columbia Glacier

Aug. 11: Columbia Glacier survey

Aug. 12: Columbia Glacier survey

Aug. 13: Hike out Columbia Hike in Mount Daniels

Aug. 14: Ice Worm Glacier survey

Aug. 15: Lynch and Daniels Glacier survey

Aug. 16: Hike out

Porcupine Glacier Major Iceberg Turns 3 Years Old, What Next?

On July 25, 2019April 25, 2024 By mspeltoIn Canada glacier retreat

Porcupine Glacier in Landsat images from 2016 and 2018 and 2019 Sentinel Image. Iceberg A and Ice tongue B are indicated on each. The haziness in 2019 is forest fire smoke. The yellow arrows mark the 2019 terminus location.

Porcupine Glacier is a 20 km long outlet glacier of an icefield in the Hoodoo Mountains of Northern British Columbia that terminates in an expanding proglacial lake. During 2016 the glacier had a 1.2 km² iceberg break off, the iceberg is still present. This is an unusually large iceberg to calve off in a proglacial lake, the largest I have ever seen in British Columbia or Alaska. NASA generated better imagery to illustrate this observation. Here we examine the change in terminus position and iceberg deterioration from 2016-2019 using Landsat images from 2015, 2016, 2018 and 2019.

In 1988 a tongue of the glacier in the center of the lake reached to within 1.5 km of the far shore of the lake, red arrow (see below). The yellow arrow indicates the 2016 terminus position. In 2015 the glacier had retreated 3.1 km from the 1988 location. In 2015 there are two tongues of the glacier vulnerable to calving at Point A and B. In 2016 Iceberg A has calved generating an immediate retreat of 1.7 km. In June of 2017 the iceberg size has been reduced 10-15%, with little change in position. The iceberg is plugging smaller icebergs from moving down the lake. In August 2018 the iceberg because of its size has still drifted little and at 0.6 km² has lost half of its area in the two years. This has enabled smaller icebergs to move past the iceberg down the lake. In July of 2019 the iceberg has diminished further to 0.45 km², but is enmeshed in a melange of other icebergs as well. The glacier has continued to retreat from 2016 to 2019 as expected, ~500 m. The glacier tongue at Point B has narrowed considerably from 2015 to 2019 and is poised to separate. The narrowness and potentially shallower depth of this inlet may make it difficult for a single iceberg to emerge from the collapse of this glacier tongue that will occur in the next couple of years, I will be watching this summer. The snowline is already approaching a typical end of summer elevation in this image is from July 1, 2019.

In Antarctica it is not unusual to see an iceberg endure for many years. In the northern hemisphere whether in a lake or in the ocean it is rare to see an iceberg last for three years as has occurred at Porcupine. This is not due to slow melt, but simply due to the size and thickness of the iceberg, and the fact that this is a wave quiet environment. The retreat here mirrors that of other glacier to the south Klinaklini Glacier and Bridge Glacier in BC and the north Excelsior Glacier and Yakutat Glacier in Alaska.

Porcupine Glacier in Landsat images from 1988, 2015 and 2017 . Iceberg A and Ice tongue B are indicated in the latter two. The yellow arrows mark the 2019 terminus location. The red arrow in 1988 marks its terminus location. The orange and purple arrows in 1988 indicate the margin where the terminus meets the lake shore.

Mendenhall Glacier, Alaska Accumulation Zone Shrinks

On July 17, 2019May 8, 2024 By mspeltoIn alaska glacier retreat9 Comments

Mendenhall Glacier in Landsat images from 1984 and 2018. Yellow arrows indicates 1984 terminus location, read arrow the Suicide Basin tributary and the purple dots the snowline.

Mendenhall Glacier is the most visited and photographed terminus in the Juneau Icefield region. The glacier can be seen from the suburbs of Juneau. Its ongoing retreat from the Visitor Center and the expansion of the lake it fills is well chronicled. Here we document the rise in the snowline on the glacier that indicates increased melting and reduced mass balance that has driven the retreat. The change in snowline from 1984-2018 and the associated retreat are documented. The snowline as July begins in 2019 is already in the end of summer range. In 1984 I had a chance to ski across the upper portion of this glacier.

Top of the Mendenhall Glacier at 1500 m looking towards ocean in 1984.

Mendenhall Lake did not exist until after 1910, in 1948 it was 2.2 km across and by 1984 the lake was 2.7 km across. Boyce et al (2007) note the glacier had two period of rapid retreat one in the 1940’s and the second beginning in the 1990’s, both enhanced by buoyancy driven calving. The latter period has featured less calving particularly in the last decade and is a result of greater summer melting and a higher snowline by the end of the summer, which has averaged 1250 m since 2003 vs 1050 m prior to that (Pelto et al, 2016). In 2005, the base of the glacier was below the lake level for at least 500 m upglacier of the terminus (Boyce et al (2007). This suggests the glacier is nearing the end of the calving enhanced retreat. It is likely another lake basin would develop 0.5 km above the current terminus, where the glacier slope is quite modest.

Terminus of Mendenhall Glacier before the 1982 field season on the Juneau Icefield.

The glacier in 1984 ended at the tip of a prominent peninsula in Mendenhall Lake. The snowline is at 950 m. In 1984 with the Juneau Icefield Research Program we completed both snowpits and crevasse stratigraphy that indicated retained snowpack at the end of summer is usually more than 2 m at 1500-1600 m. The red arrow indicates a tributary that joins the main glacier, where Suicide Basin, currently forms. In 2014 the snowline in late August is at 1050 m. The terminus has retreated to a point where the lake narrows, which helps reduce calving. In 2015 the snowline is at 1475 m. In 2017 the snowline reached 1500 m. There is a small lake in Suicide Basin. In September 2018 the snowline reached 1550 m the highest elevation the snowline has been observed to reach any year. In Suicide Basin the lake drained in early July. In 2018 Juneau Icefield Research Program snowpits indicates only 60% of the usual snowpack left on the upper Taku Glacier, near the divide with Mendenhall Glacier. On July 1. 2019 the snowline is already as high as it was in late August of 1984. This indicates the snowline is likely to reach near a record level again. The USGS and NWS is monitoring Suicide Basin for the drainage of this glacier melt filled lake. In 2019 the lake rapidly filled from early June until July 8, water level increasing 40 feet. It has drained from July 8 to 16 back to it early June Level. The high melt rate has thinned the Mendenhall Glacier in the area reducing the elevation of the ice dam and hence the size of the lake in 2019 vs 2018.

The snowline separates the accumulation zone from the ablation (melting) zone and the glacier needs to have more than 60% of its area in the accumulation zone. The end of summer snowline is the equilibrium line altitude where mass balance at the location is zero. With the snowline averaging 1500 m during recent years this leaves less 30% of the glacier in the accumulation zone. This will drive continued retreat even when the glacier retreats from Mendenhall Lake. The declining mass balance despite retreat is evident across the Juneau Icefield (Pelto et al 2013). Retreat from 1984-2018 has been 1900 m. This retreat is better known, but less than at nearby Gilkey Glacier and Field Glacier.

Mendenhall Glacier in Landsat image from 2014. Yellow arrows indicates 1984 terminus location and the purple dots the snowline.

Mendenhall Glacier in Landsat image from 2015. Yellow arrows indicates 1984 terminus location and the purple dots the snowline.

Mendenhall Glacier in Landsat image from 2017. Yellow arrows indicates 1984 terminus location and the purple dots the snowline.

Mendenhall Glacier in Landsat image from 2019. Yellow arrows indicates 1984 terminus location and the purple dots the snowline.

Penny Ice Cap NW Thinning and Retreat Evident

On July 7, 2019April 25, 2024 By mspeltoIn Canada glacier retreat3 Comments

The Northwest (NW) and Northnorthwest (NNW) outlet of the Penny Ice Cap in 1991 and 2019 Landsat images. Red arrow indicates the 1991 terminus location. Point 1 is a large proglacial, Point 2-4 are areas of emerging and expanding bedrock amidst the ice cap.

The two largest outlet glaciers of the NW quadrant of the Penny Ice Cap feed the Isurtuq River. In 1991 both outlet glaciers terminated at 600 m. Schaffer et al. (2017) noted a substantial reduction in velocity of the six largest outlet glaciers of the Penny Ice Cap from 1985-2011, 12% per decade. This is driven by mass balance losses, which drive thinning and retreat as well. Here we examine the changes from 1991-2019 of the Northwest (NW) and Northnorthwest (NNW) outlet of the Penny Ice Cap. The summer of 2019 is shaping up to feature substantial mass balance losses.

In the 1991 Landsat image the NW outlet reaches the Isurtuq River. The large 7 km² proglacial lake #1 is impounded by the glacier, it is mostly covered by lake ice in this image. At Point #3 there is no bedrock that has emerged. The NNW outlet terminates 1 km south of the Isurtuq River, upglacier Point #2 is a single bedrock outcrop and Point #4 is barely evident. In 2000 the NW outlet has receded from the river, the proglacial lake is still 7 km² and Point #3 has no evident bedrock. The NNW outlet has receded 100-200 m and bedrock at Point #2 and 4 are more evident. In 2016 the proglacial lake has diminished and now is several small lakes. At Point 3 bedrock is evident. At Point #2 there are two areas of bedrock covering 0.25 km². The snowline in 2016 is above this portion of the icecap. In 2019 the NW outlet has retreated 500 m, proglacial lake #1 has three separate parts that total less than 2 km². Bedrock at Point #2-4 has expanded significantly indicating ice cap thinning. On June 30 2019 the snowline is already above this section of the ice cap, +1100 m with two months of melting to come. Point #2 has an exposed bedrock area of 0.8 km². Look for a merging of the bedrock at Point 2 and further expansion at 3 and 4. The high snowline at +1100 m, for this early in the summer was also observed at Fork Beard Glacier just east of Penny Ice Cap and is due to very warm temperatures in June in the region.

Way (2015) noted that the Grinnell Ice Cap also on Baffin Island, has lost 18% of its area from 1974 to 2013 and that the rate of loss has greatly accelerated due so summer warming. Grinnell Ice Cap also has seen a loss of snowpack even at its crest.

The Northwest and Northnorthwest outlet of the Penny Ice Cap in 2000 and 2016 Landsat images. Red arrow indicates the 1991 terminus location. Point 1 is a large proglacial, Point 2-4 are areas of emerging and expanding bedrock amidst the ice cap.

Map of the region

Fork Beard Glacier, Baffin Island High June 2019 Temperatures and Snowline

On July 1, 2019April 25, 2024 By mspeltoIn Canada glacier retreat

Fork Beard (F) and Nerutusoq Glacier (N) Baffin Island on June 1, 2019, June 18, 2019 Sentinel images and June 30 Landsat image. Purple dots indicate the snowline.

Fork Beard Glacier (F) is an outlet glacier of a mountain glacier complex just southeast of Penny Ice Cap on Baffin Island. Nerutusoq Glacier (N) also drains from the same complex. Here we examine the rapid rise of the snowline from June 1 to June 30, 2019. This 30-day period at nearby Pangnirtung featured four days with record temperatures for that date June 5 (15.1), June 11 (13.5) and June 12 (13.6), and June 19 (14.4). There were 14 days with a maximum temperature above 10 C. Landsat images are utilized to identify the retreat and separation of Fork Beard Glacier and Nerutusoq Glacier and several neighboring glaciers from 1990-2018. Gardner et al (2012) and Sharp et al (2011) both note that the first decade of the 21st century had the warmest temperatures of the last 50 years in the region, the period of record, and they identified that the mass loss had doubled in the last decade versus the previous four for Baffin Island. This has led to fragmentation of Coutts Ice Cap and loss of snowpack at Borden Ice Cap and disappearance of ice caps near Clephane Bay all on Baffin Island.

In late July of 1990 Fork Beard Glacier terminates near the top of a steep slope at 650 m, red arrow. At Point 1 and 2 tributaries connect to the main stem of two unnamed glaciers adjacent to Fork Beard Glacier. Nerutusoq Glacier terminates at 700 m. The snowline in mid August of 1990 on Fork Beard and its adjacent glacier to the southeast is 1050 m. In 2000 at Point 1 and 2 the tributaries still connect. The terminus of Fork Beard and Nerutusoq Glacier have retreated 200-300 m since 1990. The snowline in this mid-August image is at 1150 m. By 2018 Fork Beard Glacier has retreated 600-700 m and now terminates at an elevation of 750 m. Nerutusoq Glacier has retreated 600-700 m and now terminates at an elevation of 825 m. In this late July image the snowline on Fork Beard and the adjacent glacier to the southeast (S) is again at 1050 m. At Point 1 and 2 tributary glaciers have separated from the main stem glaciers. In Sentinel images from 2019 the snowline on Fork Beard Glacier and Nerutusoq Glacier is at 800 m on June 1 rising rapidly to 1100 m by June 18. On June 30 the snowline has risen to 1150 m. from This is a higher elevation than typically seen a month or two months later in the melt season during other years. The retreat in the region is driven by warmer temperatures and rising snowlines. The glacier of Baffin Island are already primed for another poor year in 2019.

Fork Beard (F) and Nerutusoq Glacier (N), Baffin Island in 1990 and 2018 Landsat images. Red arrow indicates 1990 terminus, yellow arrow 2018 terminus, purple dots the snowline.

Map of the region indicating flow on Fork Beard, Nerutusoq and two unnamed adjacent glaciers. Red arrow indicates 1990 terminus of Fork Beard at top of steep bench.

Fork Beard (F) and Nerutusoq Glacier (N), Baffin Island in 2000 Landsat image. Red arrow indicates 1990 terminus and purple dots the snowline.

Yelverton Glacier, Ellesmere Island Extensive Retreat and Sikussak loss 1999-2018

On June 24, 2019April 25, 2024 By mspeltoIn Canada glacier retreat

Yelverton Glacier (Y) and De Vries Glacier (D) in 1999 and 2018 Landsat images. Red arrows and red dots indicate the 1999 terminus and yellow arrow the 2018 terminus. Point M indicates the area of melange or sikussak, the boundary of this area is marked by orange dots. Purple dots mark the snowline.

Yelverton Glacier is an outlet glacier from an ice cap on Northern Ellesmere Island. White and Copland (2019) identified an 85% reduction in are of eight floating ice tongues in the Yelverton Bay area. They further observed that many of the glacier including Yelverton lost a substantial area of melange that had protected the glacier fronts from contact with open water. The melange is comprised of icebergs and mulit-year sea ice and is referred to as sikussak. Here we examine Landsat images from 1999-2018 to identify the retreat of Yelverton Glacier and the loss of sikussak.

In 1999, the sikussak extends to the end of the Yelverton Glacier inlet, while the glacier terminus is 4.5 km up the inlet. De Vries Glacier terminates adjacent to the northern tip of the peninsula separating De Vries and Yelverton. In 2000, there is no change in the terminus or sikussak, the snowline is at 900 m. In 2002, the terminus region and sikussak remain unchanged, the snowline is again close to 900 m. By 2015, Yelverton Glacier has retreated to its grounding line. The sikussak that had existed is gone. In 2018, the terminus is exposed to open water and has retreated 8 km since 1999, the snowline is at 900 m. The area of sikussak that had been 6 km long has not returned and persisted since it disappeared. Pope and Copland (2012) noted the loss of multi-year land fast sea ice in the region beginning in 2005 and concluding with total loss by 2010 driven by warming. This same climate change has also driven the retreat of Trinity Wickeham Glacier and Devon Ice Cap that also released new islands. The Canadian Arctic Islands have seen widespread glacier area/mass balance loss particularly during the last two decades ( Noël, 2018).

Yelverton Glacier (Y) and De Vries Glacier (D) in 2002 and 2015 Landsat images. Red arrows indicate the 1999 terminus and yellow arrow the 2018 terminus. Point M indicates the area of melange or sikussak.

Yelverton Glacier (Y) and De Vries Glacier (D) in 2000 and 2015 Landsat images. Red arrows indicate the 1999 terminus and yellow arrow the 2018 terminus. Point M indicates the area of melange or sikussak.

Arnesenbreen, Svalbard Retreat, Separation and Surge

On June 20, 2019April 25, 2024 By mspeltoIn svalbard glacier retreat

Arnesenbreen (A) and Bereznikovbreen (B) in 1990 and 2018 Landsat images. Red arrow is 1990 terminus location, yellow arrow the 2018 terminus location and purple dots the transient snowline.

Arnesenbreen and Bereznikovbreen are glaciers in Svalbard on the east coast of Spitsbergen that in 1990 had a joint calving front near Kapp Murchison. Blaszczyk et al’s (2009) analysis identified 163 Svalbard glaciers that are tidewater 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. Some of these are surging glaciers, which are common in Svalbard. Arnesenbreen was observed to surge in the 1930’s and in 2018 a surge was observed that was initiated from its terminus, which is a more unusual type of surge (Holmund, 2018). Sevestre et al (2018) document mechanisms that help generate terminus initiated surges, include tidewater retreat from a pinning point and/or crevasses allowing meltwater rainwater to access the bed. The surge generated considerable crevassing that extended from the tidewater terminus to an elevation of 300 m, 5 km inland of the terminus. Here we examine the behavior of these glaciers using Landsat imagery from 1990-2018.

In 1990 Arnesenbreen-Bereznikovbreen had a shared 5 km long tidewater front. The transient snowline in this July image is at 200 m. The glacier terminus reach is not extensively crevassed. In 2002 the two glaciers are separating at Point 1 each having retreated ~400-500 m, crevassing remains limited. The transient snowline in 2002 is at 300 m. By 2014, Arsenenbreen has retreated 1400 m since 1990 and crevassing remains limited. The transient snowline is at 300 m, though there is a saturated zone of snowpack above this line, that suggests extensive melt up to 500 m. In 2018 the surge crevassing was most apparent in the April image of Holmund (2018). On June 30 the extensive crevassing is still evident, particularly in the 200-250 m elevation band near Point 2, but is reduced from April in the terminus zone near Point 1. By July 21 the image indicates much reduced calving in the terminus zone of the glacier. Sevestre et al (2018) note a pattern of terminus initiated surge progression, “Upward migration of the surge coincided with stepwise expansion of the crevasse field.” This is exactly what is seen at Arnesenbreen, we are also seeing the surge terminating with calving reduction at the terminus first. The short lived nature of the surge indicates the limited impact on the longer term retreat. The surge did not lead to a reconnection with Bereznikovbreen. Bereznikovbreen has retreated 700-800 m since 1990 and Arnesenbreen has retreated ~1500 m from 1990-2018.

The ongoing retreat here is like that of Svalbard glaciers in general including surging glaciers (Nuth et al 2013). Strongbreen Glacier has separated from key tributaries. The ongoing retreat has prompted the question on other surging Svalbard glaciers, can the glaciers continue to surge? On Fridtjovbreen it appears a future significant surge is unlikely. For Arnesenbreen the terminus reach below 150 m is where the glacier expands laterally and is an area of reduced slope. This configuration remains and would allow further surges unless further retreat of more than ~1500 m occurs.

Arnesenbreen (A) and Bereznikovbreen (B) in 2002 and 2014 Landsat images. Red arrow is 1990 terminus location, yellow arrow the 2018 terminus location and purple dots the transient snowline.

Arnesenbreen in Landsat image from6/3/2018 indicating zone of most extensive crevassing.

Arnesenbreen (A) and Bereznikovbreen (B) in Toposvalbard map and recent Landsat imagery from Toposvalbard.

Varied Snowcover Extent Diagnostic of Glacier NP Glacier Climate Response

On June 14, 2019April 25, 2024 By mspeltoIn glacier climate change, Glacier National Park

Snowcover extent in Landsat images from August, 1998 and 2018. S=Sperry, H=Harrison, J=Jackson, B=Blackfoot and P=Pumpelly

Five of the eight largest glaciers in Glacier National Park are clustered in a small area: Jackson Glacier, Sperry Glacier, Pumpelly Glacier, Harrison Glacier, and Blackfoot Glacier. The USGS in Glacier National Park has over the last 15 years maintained an extensive glacier monitoring program led by Dan Fagre. This program has led to consistent mass balance observations on Sperry Glacier, and repeat mapping of the 37 named glaciers, 25 of which still qualify as glaciers. The repeat mapping indicates the area lost from 1966 to 2015, (USGS, 2017). There is considerable variation between glaciers , some have lost more than 80% of their area and others having lost less than 20% during this 50 year period. Snowcover extent in late summer is a good indicator of glacier mass balance, which controls changes in glacier volume/glacier area. Glaciers that lack a persistent accumulation zone cannot survive current conditions (Pelto, 2010). Observations of the snowcover extent in years of limited snowpack illustrate which glaciers do have a persistent snowcover and can survive vs those that cannot (Pelto, 2011). Here we examine Landsat imagery from mid to late August in 1998, 2005, 2015 and 2018, all years of extensive mass loss to identify the difference in snowcover extent, which will drive mass balance loss and subsequent retreat. These images are not at the minimum snowcover extent, which usually occurs n September. For a glacier to be in equilibrium it needs more than 50% of its area to be snowcovered at the end of the melt season.

In 1998 glacier mass balance losses were significant in the region, in mid-August the accumulation area (snowcovered area) on Harrison Glacier exceeded 80%, Blackfoot Glacier was ~60 % snowcovered, Jackson Glacier ~50% snowcovered and Sperry Glacier ~30% snowcovered. In 2005 another year of minimum mass balance in the region in late August, Harrison Glacier had ~80% snowcover, Blackfoot Glacier~60% snowcover, Jackson Glacier ~40% snowcover and Sperry Glacier ~20% snowcover. In 2015 glacier volume losses in the region were again large, with Sperry Glacier having a loss of -1.22 m. The retained area of accumulation on Harrison Glacier in mid-August of 2015 was ~60%, on Blackfoot Glacier 50%, on Jackson Glacier 30-40% and on Sperry Glacier less than 20%. In mid-August of 2018 snowcover extent was greater than 75% on Blackfoot, Harrison and Jackson Glacier, while Sperry Glacier had ~40%.

The USGS identified the area of Blackfoot Glacier in 2015 as 1.5 km², a reduction of 18% from 1966-2015 and 8% from 1998-2015 (USGS, 2017). Harrison Glacier had an area of 1.7 km², losing 17% of its area from 1966-2015, and 10% from 1998-2015. Jackson Glacier had an area of 0.8 km², losing 40% of its area from 1966-2015, and 6% from 1998-2015. Sperry Glacier had an area of 0.8 km²in 2015 having lost 40% of its area from 1966-2015, and 16% from 1998-2015. The persistent pattern of limited snowcover extent on Sperry Glacier indicates why the percentage of area loss has been greater than on the other glaciers. The lack of significant retained snowcover indicates Sperry Glacier cannot survive current climate. The retention of significant snowcover on Blackfoot and Harrison Glacier even in low snowpack years indicate these glaciers, unlike most in the National Park, can survive the current climate. The Jackson Glacier is in between these two scenarios.

Jackson is the lowest elevation glacier and Harrison is the highest. Blackfoot, Jackson and Sperry are all north facing. Pumpelly which faces south has lost the least area of the five glaciers from 1998-2015. This underscores the utility of Landsat imagery in assessing glacier mass balance response. Three of the glaciers that retain significant snowcover indicates these glaciers are not as vulnerable to warming and will continue to persist until 2050 at least.

USGS Data on glacier area.

Observation Year	LIA	1966	1998	2005	2015
Jackson	3.1	1.3	0.8	0.8	0.8
Harrison	3.5	2.1	1.8	1.7	1.7
Blackfoot	5.0	1.8	1.6	1.6	1.5
Sperry	3.8	1.3	1.0	0.9	0.8

Snow cover extent in Landsat images from August, 2005 and 2015. S=Sperry, H=Harrison, J=Jackson, B=Blackfoot and P=Pumpelly

**Sholes Glacier August, 24 2016 with the snowcover extent vs the exposed glacier ice.**

USGS Topo Map of the area with the blue line indicating the 8000 foot contour.

Asejiaguo Glacier, China Retreat and Lake Expansion

On June 10, 2019April 25, 2024 By mspeltoIn china glacier retreat, climate change glacier retreat

Asejiaguo Glacier in Landsat images from 1993 and 2018. The yellow arrow indicates the 2018 terminus and the red arrow the 1993 terminus location. Point 1 and 2 are areas of expanding bedrock in the 5400-5600 m.

Asejiaguo Glacier drains east from the China-Nepal Border and is at the headwaters of the Yarlung Tsangpo, which becomes the Brahmaputra River. The Yarlung Tsangpo powers the 510 MW Zangmu Hydropower Station. Gardelle et al, (2013) identified this glacier as part of the West Nepal region, which experienced mass loss averaging -0.32 m/year from 1999-2011. The changes of the Asejaguo Glacier are examined for the 1993 to 2018 period using Landsat imagery. Neckel et al (2014) examined changes in surface elevation of the glaciers and found this region lost 0.37 m/year from 2003 to 2009.

In 1993 the glacier terminated in a small proglacial lake that is ~1 km long at 4900 m. At Point 1-2 there is limited exposed bedrock at 5400-5600 m, which is near the snowline, the head of the glacier is at 6000 m. There is a prominent medial moraine that begins at 5300 where the north and south tributaries join. The greater width of the southern tributary indicates this is the large contributor. In 1994 the snowline is higher at 5500 m, but there is still only a small outcrop of bedrock at Point 2. By 2016 the proglacial lake has expanded to a length of over 2 km. At Point 1 and 2 there is a greatly expanded area of bedrock, and the separation of a former tributary near Point 1 from the main glacier. In November 2018 there is fresh snowfall obscuring the exposed bedrock at Point 1 and 2. The retreat from 1993-2018 is 1.5 km, and the expanding proglacial lake is over 2.5 km long. The expanding bedrock areas in the 5400-5600 m range indicate the reason rise in snowline that has generated mass loss and ongoing retreat.

The behavior of this glacier matches that of other glaciers in the regions such as Chako Glacier and Ribuktse Glacier

Asejiaguo Glacier in Landsat images from 1994 and 2016. The yellow arrow indicates the 2018 terminus and the red arrow the 1993 terminus location. Point 1 and 2 are areas of expanding bedrock in the 5400-5600 m.

Asejiaguo Glacier, blue arrow indicate flow direction, M indicates the medial moraine, the China-Nepal border is also noted.

Daishapu Glacier, China Retreat Lake Expansion

On June 4, 2019April 25, 2024 By mspeltoIn china glacier retreat

Daishapu Glacier (D) and Ruorangqubu Glacier (R) in 1993 and 2018 Landsat images. The yellow arrows indicate the 2018 terminus location of both glaciers and the purple dots the snowline. Notice the lake expansion at the terminus of both glaciers. Locations 1-4 are tributaries.

Daishapu Glacier and Ruorangqubu Glacier are in the eastern Himalaya located just north of the Himalayan divide and draining north into the Yarlung Zangbo. This is a remote area with little development downstream for 100+ km. Li et al (2010) examined glacier change over the last several decades in China and found ubiquitous glacier retreat and commonly lake formation as glaciers retreated.

In 1993 Daishapu Glacier has a debris covered terminus ending in a 1 km long proglacial lake at 5000 m. Tributaries 1-4 all reach the main Daishapu trunk. The snowline in 1993 is at 5600 m in December. Rurorangqubu Glacier had a low slope debris covered terminus without a proglacial lake at 5300 m. A tributary from the east joins the glacier 1 km above the terminus. By 2001 Daishapu has retreated several hundred meters, while tributaries 1-4 all still connect. The snowline is at 5800 m in December. Rurorangqubu still has no proglacial lake. In 2015 both glaciers have proglacial lakes at the terminus. Tributary #2 no longer reaches the main Daishapu. The eastern tributary no longer reaches the main trunk of Rurorangqubu Glacier. In 2018 the proglacial lake at the end of the Daishapu Glacier is 1800 m long, with a retreat of 700-800 m since 1993. Tributary #4 has now begun to detach. Rurorangqubu Glacier has a 600 m long proglacial that has formed which represents the retreat of the glacier since 1993. The snowline in 2018 is at 6000 m in December. The high snowline persisting into December is a trend in the area that is not positive for glacier mass balance, this has been observed around Mount Everest and on the China-Bhutan border. These two glaciers at the crest of the Eastern Himalaya are both retreating, have expanding proglacial lakes and separating tributaries. This is a common story in the region as seen at Thong Wuk Glacier and Jiongla Glacier.

Daishapu Glacier (D) and Ruorangqubu Glacier (R) in 2001 and 2015 Landsat images. The yellow arrows indicate the 2018 terminus location of both glaciers and the purple dots the snowline. Notice the lake expansion at the terminus of both glaciers. Locations 1-4 are tributaries.

Sulmeneva Bay Glacier Retreat 1990-2018, Novaya Zemlya

On May 28, 2019April 25, 2024 By mspeltoIn Novaya Zemlya glacier retreat

Sulmeneva Bay Glacier in Landsat images from 1990 and 2018. Red arrow is the 1990 terminus location, yellow arrow the 2018 terminus location and pink dots the snowline.

Here we examine an unnamed glaciers, referred to here as Sulmeneva Bay Glacier, that terminated in a piedmont lobe near the northern shore of Sulmeneva Bay and just east of Lednikovoye Lake in central Novaya Zemlya. Sulmeneva Bay is on the west coast of Novaya Zemlya and is the southern most extent of the continuous glaciation that extends along the northern half of the island. LEGOS (2006) identified a 1.24 km² reduction in area of this glacier from 1990-2000. Carr et al (2014) identified an average retreat rate of 52 meters/year for tidewater glaciers on Novaya Zemlya from 1992 to 2010 and 5 meters/year for land terminating glaciers. The glacier is retreating like all tidewater glaciers in northern Novaya Zemlya, though they are not specifically tidewater the lake terminating glaciers were retreating at a similar rate of ~40 m/year from 1986-2015 (Carr et al., 2017). Here we use Landsat images to examine changes from 1990 to 2018.

In 1990 Sulmeneva Bay Glacier terminates in a proglacial lake at the southern end of what will become an island in the lake. The lake is 1.1 km wide from the calving front to the southern shore, red arrow. The snowline in 1990 is at 550 m, while the head of the glacier is at 650 m. By 2001 the glacier has retreated 700 m and the snowline is at 600 m reaching the ice divide in some areas. In 2015 the snowline is at 400 m and the lake has continued to expand with a north-south reach of 1.7 km. The glacier terminates at the northern end of the developing island.

In August of 2018 the snowline is at 550 m, again leaving a limited accumulation zone. By mid-September snowfall has lowered the snowline back to 200 m. The glacier has now retreated from the central island in the proglacial lake. This should lead to an increase in calving. The glacier has retreated 1.2 km since 1990 and the lake is now 2.2 km from the calving front to the southern shore.

The retreat here is similar to the glaciers of Lednikovoye Lake and to Sulmeneva Glacier which retreated less, but across a broader front. What is evident is that the persistent high snowlines are leading to negative mass balances that will drive continued retreat. At Lednikovoye Lake high snowlines in 2000 and 2016 further indicate the spatial extent and temporal frequency of high snowlines in recent years.

Sulmeneva Bay Glacier in Landsat images from 2010 and 2015. Red arrow is the 1990 terminus location, yellow arrow the 2018 terminus location and pink dots the snowline.

Novaya Zemlya map produced by Christoph Hormann with Sulmeneva Bay Glacier (SSG) shown just west of Lednikovoye Lake.

Chickamin Glacier, Alaska Retreat Generates Separation and Lake Expansion

On May 20, 2019April 25, 2024 By mspeltoIn alaska glacier retreat

Chickamin Glacier, Alaska in 1985 and 2018 Landsat images indicating the 3.5 km retreat and associated lake expansion. Red arrow is 1985 terminus location, yellow arrow is the 2018 terminus location, pink arrow is former junction area with Through Glacier. The purple dots indicate the snowline. Point 1 and 2 are locations of bedrock expansion above the equilibrium line altitude.

Chickamin Glacier in southeast Alaska glacier drains south from an icefield near Portland Canal and straddling the border with British Columbia. The glacier ended on an outwash plain in 1955 at an elevation of 250 meters. Shortly thereafter a lake began to form, and by 1979 a Landsat image indicates a lake that is 1300 meters long and a retreat of ~2.5 km from 1902-1979 (Molnia, 2008). The glacier at that time was fed by a substantial tributary entering from the south ~5 km above the terminus, Through Glacier-pink arrow. Here we examine Landsat images from 1985-2018 to identify the response to climate change.

In 1985 the glacier terminated at an elbow in the lake where the lake both narrows temporarily and turns east, red arrow. The glacier had terminated close to this location for 30 years. The snowline is at 1150 m, and Through Glacier still connects to Chickamin Glacier. At point 1 and 2 the area of exposed bedrock is limited. In 1994, the glacier has retreated 500 m from the elbow. Through Glacier has separated from Chickamin Glacier. The snowline in 1994 is at 1125 m. In 2013, Through Glacier has retreated 1600 m from Chickamin Glacier. Chickamin Glacier has retreated 2 km since 1985 and the snowline is at 1250 m. By 2018 Chickamin Glacier has retreated 3.5 km since 1985 a rate of just over ~100 m/year, yellow arrow. The terminus is currently at a point where the lake narrows, which should reduce the retreat rate. In 2018, the snowline reached 1525 m, leaving only 10-15% of the glacier in the accumulation zone. The exceptionally high snowline in 2018 was also noted at Taku Glacier. The snowline from 2014-2018 has persistently been above 1350 m, which indicates substantial negative mass balance for the glacier that will drive continued retreat. The persistent snowline elevation above 1250 m is indicated by the expansion of bedrock areas at Point 1 and 2 from 1985 to 2018, which both are located in what was the typical accumulation zone prior to that time.

The sustained mass balance losses follow that of Lemon Creek Glacier, which has a a long term record from 1953-2018 indicating a loss of ~-0.5 m/year (Pelto et al. 2013). The retreat and lake expansion has become a chorus with more than 20 coastal Alaskan glaciers having at least a 2 km lake expansion due to retreat since 1984, documented individually in previous posts at this blog.

Chickamin Glacier, Alaska in 1994 and 2013 Landsat images indicating the 3.5 retreat and associated lake expansion. Red arrow is 1985 terminus location, yellow arrow is the 2018 terminus location, pink arrow is former junction area with Through Glacier. The purple dots indicate the snowline. Point 1 and 2 are locations of bedrock expansion above the equilibrium line altitude.