Rainbow Glacier: Record Ablation in 2014 for 1984-2014 Period

On October 5, 2014October 6, 2014 By mspeltoIn Glacier Observations

From 1984-2014 we have monitored the mass balance of the Rainbow Glacier on Mount Baker, North Cascade Range, Washington. This entails detailed monitoring of snowpack depth in July and August, and subsequent ablation to the end of the melt season. On July 13th the glacier was completely snowcovered. By August 10th the snowline had risen to 1575 m, with 1.4 m of ablation since July 13th. We measured the snowdepth at 85 locations on the glacier, with only 6 measurements exceeding 3.5 m on Aug. 10th.

Ben Pelto and Ashley Edwards examining crevasse stratigraphy both the 2013 and 2014 layers evident.

Limited snowpack below the main icefall at 1750 m on Aug. 10.

Minimal 2014 snowpack in crevasses at 1650 m on Aug. 10th 1.25 m. — Limited snowpack below the main icefall at 1750 m on Aug. 10.

By September 27th the snowline had risen to 1975 m with a few pockets of snow retained where the snowdepth had exceeded 3.2 m on Aug. 10th. Snowdepth at the Sept. 27th snowline had been 3.0 to 3.2 m on Aug. 10th. This indicated ablation of approximately 3 m of snowpack, 1.8 m of water equivalent from Aug. 10th to Sept. 27th. Ablation from July 13th to Sept. 27th was 5.3 m of snowpack and 3.2 m w.e. This was 5-10% more ablation than any other year since 1984. A comparison of images from the ground on Aug. 10th indicates the snowpack on the glacier from 1550-1950 m, the blue arrows indicate locations where a patch of 2014 snow remained on Sept. 27th. The Sept. 27th image was taken by Tom Hammond from Rainbow Ridge the only location where the whole glacier can be viewed. The firn is simply old snow that survived a summer and could be from 2012 or 2013.

Tom Hammond Image adusted to show firn, ice and retained snow. Sept. 27th

Winter snowpack was normal on Mount Baker, the record ablation then led to a large negative mass balance for the glacier of -1.8 m, but not a record loss. The ablation did lead to many significant surface streams on the glacier shown below, which drain into the glacier at moulins.

The terminus of glacier retreated rapidly from 1984 to 1998, but has slowed as it currently is in an avalanche runout zone. We visited the terminus in 1984 and all retreat is measured from that point when the glacier was in contact with an advance moraine from the 1955-1980 period of advance. A comparison of 1993 and 2006 Google Earth images indicates the retreat, red outline 2006 margin and black outline 1993. The 2014 image taken by Tom Hammond indicates that the terminus did get exposed in 2014 which will lead to additional retreat when we measure the terminus position next summer. Total retreat from 1984 to 2014 is 490 m.

Picture of the terminus in 2014 indicating the 214 and 1984 position. Taken by Tom Hammond from Rainbow Ridge.

Whitney Glacier Retreat and Thinning, Mount Shasta, California

On September 30, 2014October 2, 2014 By mspeltoIn Glacier Observations

Mount Shasta is a stratovolcano home to the largest glaciers in California. Of the seven glaciers on the mountain Whitney Glacier on the north side is the longest. The last two years 2013 and 2014 have seen hot dry summers separated by a dry winter in 2013/14, see below, how are the glaciers responding? In 1981 USGS (Driedger and Kennard, 1986) mapped the area and volume of several of the glaciers, in a landmark study of glacier volume on Cascade volcaones. Whitney Glacier had an area of 1.3 square kilometers, a maximum depth of 38 m, and a volume of 25 million cubic meters. The glacier was noted as having a length of 3.0 km ending on the USGS map at 9900 feet.
January satellite image of Mount Shasta’s limited snowpack

Topographic map of Mt. Shasta.

A UCSC study looking at the change in the glaciers from 1944 to 2003 noted an expansion of the Mount Shasta glaciers that when published in 2008 was in contrast to most alpine glaciers globally or in the Pacific Northwest. Tulaczyk and Howat (2008) noted that Whitney Glacier had advanced 850 m since 1951 to 2003, but when did retreat begin? There was a period of advance for many Cascade volcanoes glaciers between 1950 and 1980, but retreat after. For example on Mount Baker all of the glaciers advanced during the 1944-1979 period by an average of 480 m (Pelto and Hedlund, 2001). By 2010 Pelto and Brown (2012) observed all were retreating with an average retreat of 370 m. In 2003 all of them all had retreated , but many were in advance of their 1944 position. By 2014 the retreat has exceeded the advance from 1944 on most Mount Baker glaciers, more on this in the next post. This is an important point for Mount Shasta too, Whitney Glacier was advancing in 2003 but had been retreating in the late 1980’s and 1990’s. Whitney Glacier was further advanced than in 1944, but how short lived was the advance? Here we examine satellite images from 1987 to 2014 to identify recent trends, along with Google Earth imagery of termini of several glaciers and the 1981 USGS observations.

The first sequence is a 1987, 2013 and 2014 Landsat image with a pink arrow at the top of Whitney Glacier indicating the expansion of bare rock at the head of the glacier. The purple arrow is at the 1987 terminus, which indicates some retreat and also thinning by 2013.

In between 1987 and 2013 of course was the period of advance and then retreat that is examined in the second sequence of images from Google Earth of the glacier in 1993, 2003, 2005, 2012 and 2014. It is evident that the glacier did expand between 1993 and 2005, as Tulaczyk and Howat (2008) had noted the advance period was unusual. The advance was likely limited to the 1999-2005 period due to heavy snowfall from 1998-2002. The 2005 terminus is quite near the 1981 terminus position indicating a period of retreat in the 1980’s and 1990’s. In 2003 and 2005 there is extensive crevassing at the blue arrows. The glacier terminus margin is indicated by a red line for 2003, pink line for 2005 and orange line for 2012 and green for 2014. It is evident that the zone of heavy crevassing and significant ice motion in 2003 and 2005 is in the vicinity of the 2012 terminus. By 2012 and 2014 the glacier is thin in its lower reaches with no crevassing. This indicates the retreat will be continuing. By 2014 the terminus of the glacier had retreated 700 m from 2005 and is now 2.6 km in length and terminates at 10,200 feet, 400 feet higher than a decade before or in the 1981 map. A closeup of the terminus in 2012 indicates the thin uncrevassed nature with surface streams incised into the ice. There are some areas of ice cored moraine beyond the current terminus.

The retreat of glaciers on Mount Shasta leads to thinner ice and lower velocities, but can also lead to ice failure and avalanching, along with more subglacial melt pockets-caves developing. This is likely beyond the recent small outburst flood on Mt, Shasta. The reduced velocity high on Whitney Glacier is evident from observations of a key crevasse set higher on the glacier beginning at an elevation of 11700 feet. The red arrows point out what is a bergshrund along most of its length separating the glacier from the surrounding non-glacier snowfields. The blue arrows indicate crevasses below the bergshrund. Note that the vertical and horizontal offset of the bergshrund had declined from 1998 to 2014, and the number and extent of the crevasses has also declined. Both indicate reduced acceleration and velocity.

1993 Google earth image

2003 Google Earth image

2005 Google Earth image

2012 Google Earth Image

2014 Google Earth image

2014 Terminus closeup

2014 Ice Cored moraine areas

Glacier Ice Worms in Action

On September 25, 2014September 25, 2014 By mspeltoIn Glacier Observations5 Comments

On glaciers in the coastal ranges of the Pacific Northwest glacier ice worms thrive. Their diet as far as we have seen from looking in their gut is algae. They cannot survive during daylight hours on the surface of the snow with even indirect solar radiation. They can survive on the surface of glacier ice if bathed in meltwater. When we leave the edge of a glacier and cross onto a snowfield that persists in many years, the number of ice worms plummets from 100-400 worms/square meter to zero within 20 m. This suggests that ice worms do not tend to roam off glaciers. There movement is relatively vertical, so they cannot migrate around a glacier to remain on a snowcovered section. Since their diet is largely algae, which can thrive in snowpack, what happens to this diet when the snowpack is lost and they have to exist on the glacier ice? If this period of existence on the ice is expanded due to earlier snow melt, is this a significant stress? This latter question is what I was pondering while observing and filming the ice worms on the surface of Sholes Glacier on August 11th, 2014. The snowpack had been lost and yet there was still at least 7 weeks left in the melt season. The snowpack had been lost in 2013 in early August as well. In 2014 monitoring the ice worm population in the same location as every year, the numbers were the lowest we had seen since 2005 also a low snowpack year following a low snowpack year. The population did rebound in 2007 and 2008 with better snowpack. The data does not answer the question, but is suggestive that repeated low snowpack occurring with significant periods left in the melts season may reduce glacier ice worm populations. You may think why does that matter, but in fact on Sholes Glacier the population of glacier ice worms based on our surveys is approximately 200 million. The process of answering this question will continue.

Landsat image of Sholes Glacier 9/12/2013 with the red dots indicating the snowline separating blue ice from snowcover.

Landsat image of Sholes Glacier 9/15/2014 with the red dots indicating the snowline separating blue ice from snowcover.

This is the best video of ice worm motion that I have captured.

This is an overall assessment of ice worms.

Boston Glacier Retreat, North Cascade Range, Washington

On September 21, 2014 By mspeltoIn Glacier Observations

Boston Glacier is the largest glacier in the North Cascades with an area of just over 6 square kilometers. The is a steep, wide slope glacier that currently lacks any type of main terminus tongue or valley section. The glacier is extraordinarily heavily crevassed this is due a steep slope, a smooth hard bedrock basal slope and high accumulation rates. In 1986 the first time I stepped onto this glacier is was immediately apparent that traversing the glacier in any direction was not wise and this glacier would be a poor choice for detailed observations. Richard Hubley, UWashington in the 1950’s chronicled the beginning of an advance for the glacier. A series of aerial photographs of this glacier from 1960 to 1979 by Austin Post, USGS indicate the glacier remained in an advanced position. By 1998 Granshaw and Fountain (2006) noted retreat and glacier area loss had begun. Here we examine a series of images from 1955-2014 to identify the changes in the terminus and crevassing on this glacier.

In each image C,I and T are in the same location. In 1955 the Richard Hubley image indicates the main terminus has advanced down a steep bedrock step to a small basin, I indicates the west side of the step. In 1972 an Austin Post image indicates the main terminus has descended a second step to end at a small lake basin (T). The crevasse density in a grid of 40,000 square meters around point C indicate that 55% of the glacier surface is a crevasse feature. A 1998 Google Earth image indicates the terminus has retreated from the small lake basin (T) but is still below the steep bedrock step (I), a 200-250 m retreat. At Point C crevassing has been reduced to 30% of the surface area.

1955 Richard Hubley image

1972 Austin Post image

1998 Google Earth image

By 2005 and 2006 the glacier has retreated from the basin below the steep bedrock step a retreat of 650 m since 1972, and 400 m since 1998. Crevassing at Point C is nw 25% of the surface area. This indicates crevassing has decreased by 50% since 1972. This glacier remains large and vigorous in its flow. The decrease in crevassing indicates some deceleration. The crevasse pattern is caused by the thin ice, for the size of the glacier, passing over small bedrock knobs. The red arrows in the last image indicate the deglaciated bedrock knobs and the blue arrows the pattern of crevassing going over the knob. This is a 2009 picture, the terminus is quite thin indicating retreat is ongoing. The retreat of this glacier follows that of Quien Sabe Glacier over the ridge to the south and McAllister Glacier 10 km to the west. The glacier is like all 47 glaciers we have observed in the North Cascades retreating.

2005 image

2006 Google earth image

2006 image taken by Leor Pantilat

Robson Glacier Retreat, Alberta

On September 16, 2014September 17, 2014 By mspeltoIn Glacier Observations

Robson Glacier is the largest glacier on the highest mountain in the Canadian Rockies. The glacier begins at 3200 m and drains northeast from the summit ending in a proglacial lake at 1720 m. The glaciers upper west side has heavy avalanche accumulation from Mount Robson’s upper slopes, note the 1964 photograph from the legendary USGS glacier guru Austin Post. The history of this glacier has been examined using tree rings and lichenometry. Heusser (1954) observed that the glacier reached its Little Ice Age Maximum arond 1780 and had retreated at a rate of 2 m/year from then until 1908 and at a rate of 16 m/year from 1908-1953. The terminus history up to 2006 is summarized in a map from Roger Wheate (UNBC)and Laura Thomson that indicates, a minor retreat of 300 m from 1850 to 1922, a rapid retreat from 1922-1950 of 1200 m, a readvance from 150 to the 1980’s of 300 m and a resumed retreat of 500 m from the 1980s to 2005. Here we examine satellite imagery from 1987-2014 to see more recent changes.

Robson map from Wheate (2012)

Austin Post 1964 Photograph

In each image the red arrow indicates the 1987 terminus position, the yellow arrow the 2013 terminus position and the pink arrow a bedrock step on the east margin of the glacier. In 1987 the proglacial lake at the terminus is 350 m long. The bedrock step on the eastern margin is largely buried under the glacier and the snowline is at 2300 m though the melt season still has six weeks to go. In 1989 the terminus is not quite as wide and the snowline is at 2500 m. By 2002 the glacier has retreated 400 m with the proglacial lake having expanded into a new narrower section. The bedrock bench is more prominent adjacent to the glacier and now extends as a bare rock further into the main glacier. The snowline is at 2400 m. By 2006 the glacier has retreated an additional 100 m and the snowline is at 2500 m. There are two apparent bedrock ribs the upglacier one extends 300 m toward the glacier center from the east margin and the lower rib 150 m. This represents most of the flow from the eastern tributary of the glacier that extends only to 2800 m and has less avalanche contribution. By 2013 the glacier has retreated 700 m since 1987, a rate of 30 m/year. This is a more rapid rate than the retreat observed from 1908-1953.The snowline is just above 2500 m. In 2014 the terminus position is a bit obscured in this September image, the bedrock rib is more prominent than in 2006 and the snowline is again above 2500 m, with three weeks left in the melt season.

It is apparent that a zone of persistent and consistent accumulation remains above 2600 m on Robson Glacier, and that it can survive current climate change. The recent trends of a snowline above 2500 m indicates that retreat will continue in the near future in response to current climate. Both 2013 and 2014 have been warm summers leading to above average melt conditions that should lead to rapid thinning of the lower terminus tongue and rapid retreat in the next several years. Hopefully another satellite image will be obtained to indicate the end of season snowline (ELA). The retreat of the is glacier parallels that of Coleman Glacier just east of Mount Robson, Freshfield Glacier and Columbia Glacier.

1987 Landsat image

1989 Landsat image

2002 Landsat image

2006 Google earth image

2013 Landsat image

2014 Landsat image

Robson Glacier Retreat, British Columbia

On September 16, 2014May 3, 2024 By mspeltoIn Glacier Observations7 Comments

Robson Glacier is the largest glacier on the highest mountain in the Canadian Rockies. The glacier begins at 3200 m and drains northeast from the summit ending in a proglacial lake at 1720 m. The glaciers upper west side has heavy avalanche accumulation from Mount Robson’s upper slopes, note the 1964 photograph from the legendary USGS glacier guru Austin Post. The history of this glacier has been examined using tree rings and lichenometry. Heusser (1954) observed that the glacier reached its Little Ice Age Maximum arond 1780 and had retreated at a rate of 2 m/year from then until 1908 and at a rate of 16 m/year from 1908-1953. The terminus history up to 2006 is summarized in a map from Roger Wheate (UNBC) and Laura Thomson that indicates, a minor retreat of 300 m from 1850 to 1922, a rapid retreat from 1922-1950 of 1200 m, a readvance from 150 to the 1980’s of 300 m and a resumed retreat of 500 m from the 1980s to 2005. Here we examine satellite imagery from 1987-2014 to see more recent changes.

Robson map from Wheate (2012)

Austin Post 1964 Photograph

1989 Landsat image

2002 Landsat image

2006 Google earth image

2013 Landsat image

2014 Landsat image

Fraser Glacier, Separation and Retreat Alberta

On September 11, 2014September 12, 2014 By mspeltoIn Glacier Observations

Fraser Glacier, Alberta on the southern flank of Bennington Peak in Jasper National Park drains into the Athabasca River not the Fraser River. The glacier was reported in the USGS satellite image atlas as having a length of 3.5 km in the 1970’s. In Canadian Topographic maps the glacier extends for over 3.0 km from 2900 m to 2200 m. Today the glacier is barely half that length. The glacier first separated and then the lower section has now melted away. Here we use Google Earth and Landsat imagery from 1996 to 2014 to identify the changes. Bolch et al (2010) noted that from 1985-200 Alberta Glaciers lost 25% of their area. Tennant et al (2012) noted that from 1919-2006 the glaciers in the central and southern Canadian Rocky Mountains lost 40% of their area. Of the 523 glaciers they observed 17 disappeared and 124 separated, Fraser Glacier falls into the latter category.
In each image Point A indicates the same location which after 2000 a small lake develops, Point B, is the location where the glacier separated into two parts. The red arrow indicates the lower section and the yellow arrow the position of the upper terminus in 2014. In the map the orange outline is the glacier boundary on the map, while the green line is the 2005 boundary.

By 1999 the glacier has separated into two parts, but no lake exists yet at Point A. By 2002 a small lake is developing at Point A and the separation between the upper and lower glacier has increased. By 2005, a Google Earth image indicates the diminishing lower section of the glacier is 300 m long and less than 200 m wide, separated from the upper glacier by 250 m. By 2013 the lower glacier is no longer evident, there could be a small remnant of debris covered ice, but it is essentially gone. The glacier now is just 1.6 km long having lost half its length from the mapped glacier and more than half since the satellite image analysis of the 1980’s. The upper margins of the glacier have changed little and some snowpack has been retained. This suggests that now with the entire glacier in the upper basin above 2400 m, the retreat should slow down,and that the glacier can survive current climate (Pelto, 2010). The retreat of this glacier is similar to Apex Glacier, Petain Glacier, Coleman Glacier and Mangin Glacier. The retreat fits the pattern noted by Tennant et al (2012), further Jiskoot et al (2009) noted that the glaciers of the nearby Chaba-Clemenceau Icefield are experiencing faster retreat rates in recent years. All of this loss in glacier area of course means less glacier runoff, since the area lost is greater than the increased melt rate from the remaining glacier area in Alberta.
2005 Google Earth image

1996 Landsat image

2002 Landsat image

2013 Landsat image

2014 Landsat image

Strongbreen Retreat, Fjord Expansion, Svalbard

On September 8, 2014September 8, 2014 By mspeltoIn Glacier Observations

Strongbreen is a glacier in Svalbard on the southern part of Spitsbergen draining east into the Kvalvagen Fjord. 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. One glacier they observed having separated from neighboring glaciers was Strongbreen, which they noted was retreating at a rate of approximately 40 m/year since the previous inventory. The glacier had been connected with the Kvalbreen and Perseibreen Glacier. They also identified this as a surging glacier with the last known surge in the 1870’s.

Map from TopoSvalbard

Here we examine Landsat images from 1990. 2002, 2014 and a Digital Globe image from 2010, to identify changes in the glacier over the last 25 years, the colored arrows are in the same location in each image. In 1990 the glacier extended down fjord to the red arrow and yellow arrow on the south side and north side of Kvalvagen respectively. On the southern side the terminus is at Sergievskijfjellet. Kvalbreen at the pink arrow terminates nearly parallel with the northern shore of the fjord. At the blue arrow is the glacier junction with a very small glacial dammed lake between the glacier and the adjacent mountain. By 2002 a small fjord is beginning at the pink arrow where Kvalbreen terminates. Strongbreen on the southern side of the fjord has a much narrower connection to the peninsula at the red arrow and has retreated on the north side from the yellow arrow. By 2014 the glacier has retreated to the green arrow on the southern side of the fjord from the red arrow, a distance of 3.75 km in 24 years. On the northern side the glacier has retreated almost to the orange arrow a similar distance of 3.5-3.8 km. This is a retreat of 150 m/year for Strongbreen quite an acceleration. Kvalvagen has retreated 1 to 1.25 km up the newly developing fjord, a retreat of 1 km in 25 years, 40 m/year. The glacial dammed lake at the blue arrow has expanded. A better view of this lake is in the 2010 image, last one, indicating that the lake now is almost half the tributary glacier width. The expansion of this lake will lead to this tributary having a separate terminus and undermine the stability of the lower section of Strongbreen.

The lower portion of the glacier is largely uncrevassed indicating quite slow velocities. Blaszczyk et al (2009) report a velocity of less than 30 m/year from 2000-2006. The low slope, limited crevassing, expanding supraglacial lake all indicate continued retreat. It then seems likely the glacier will separate into two fjords with a southern and a northern arm. The only thing that could forestall the retreat for a brief period is a surge as happended on nearby Perseibreen in 2000 (Dowdeswell and Benham, 2003). The retreat of this glacier paralells that of other glaciers in southern Svalbard: Vasilievbreen, Olsokbreen, Hornbreen and Hambergbreen.

1990 Landsat image

2002 Landsat image

2014 Landsat image

2010 Digital Globe image posted in TopoSvalbard.

Vasilievbreen Glacier Retreat, Svalbard

On September 4, 2014September 8, 2014 By mspeltoIn Glacier Observations3 Comments

Vasilievbreen is a glacier that terminates on the east coast of the southern island of Svalbard a short distance southeast of Hornsund. In 1990 this glacier had a single continuous terminus margin along the coast. The glacier retreated 50 m/year from 1936 to 1990, as the embayment of Isbukta expanded. The glacier has since separated into distinct termini, on each image colored arrows indicate the same specific location, red arrow a developing island named Fallknatten, yellow arrow the tip of peninsula called Gedenovfjellet, the orange arrow an island called Morenetangen, the green arrow an emerging island not evident on the map and the purple arrow an area of new coastline on the south side of Isbukta. Blaszczyk et al (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. One glacier they observed having separated was Vasilievbreen. A more detailed examination by the same researchers, Blaszczyk, Jania and Kolondra(2013) reported the total area of the glacier cover in Hornsund Fjord from 1899–2010 diminished by approximately 172 km2. The average glacier area retreat increased from a mean of 1.6 square kilometers per year to 3 square kilometers per year since 2000. The Polish Polar Station at Hornsund is an ideal location from which to conduct annual field research on the glacier and arctic environment in the area.
Map from TopoSvalbard

Here we use Landsat imagery to examine the changes in Vasilievebreen from 1990-2014. In 1990 the terminus is continuous. The glacier reaches the coastline at the purple arrow. There is no evident land at the green arrow. The terminus approaches quite close to the island at the orange arrow and there is a nunatak surrounded by ice at the red arrow. By 2002 Vasilievbreen is no longer a continuous terminus. The glacier at the purple arrow has retreated from the sea, exposing a narrow strip of coastline. At the green arrow some bedrock has emerged that will become islands. At the orange arrow the glacier has retreated from the vicinity of the island. By 2014 The strip of land at the purple arrow has expanded to a length of 2km and a width of 300-500 m, this is a retreat of 400 m. At the green arrow a 3 km long rib of bedrock is exposed and the glacier has retreated 500 m since 1990. At the red arrow the nunatak of 1990 is now at the terminus of the glacier and is much larger, a retreat of 750 m. At the yellow arrow the end of a peninsula is now much closer to the ocean, a retreat of 900 m. At the orange arrow this moraine based island has been eroding, but is also much further from the glacier, a retreat of 800 m. The glacier now has five distinct terminus segments that can retreat independently of each other. That this retreat occurred along a front that is 20 km long represents a loss in glacier area of approximately 10 square kilometers. This is more significant than the actual distance of retreat. The snowline on the glacier in 2014 is above 300 m with the melt season still going, this leaves most of the glacier in the melt zone. The retreat and changing nature of this glacier paralells that of other glaciers in southern Svalbard: Nannbreen, Olsokbreen, Hornbreen and Hambergbreen.

1990 Landsat image

2002 Landsat image

2014 Landsat image

2010 Image from Toposvalbard

North Cascade Glacier Climate Project 2014 Field Season (31st Annual) Preliminary Results

On August 31, 2014September 1, 2014 By mspeltoIn Glacier Observations1 Comment

The 2014 Glacier Field season was our 31st consecutive year working on North Cascade glaciers. After a late winter surge of snowfall, the North Cascades had a slightly above average snowpack as the melt season began in early May. The warm, dry summer to date, could end up being the warmest for the region, currently 2013 was the warmest melt season. The result is glacier melt has been high overall. In the field we measured the mass balance, terminus position, surface elevation and runoff from North Cascade glaciers. This includes assessment of annual retained snow layer thickness in crevasses and overall crevasse depth.

We first examined the Easton Glacier on the south side of Mount Baker, which has now retreated 370 m since 1990. The glacier has retreated 55 m in the last two years. The most interesting change is that the western toe of the glacier has receded beyond its normal drainage channel, and there is no outlet stream from the west side of the glacier. Snowpack below 2100 m was much below normal including on the bench at 1900 m below the main icefall. Above this main icefall snowpack was closer to normal. Snowpack average 4.5 m at 2500 m, assessed in numerous crevasses. The ongoing warm conditions will continue to reduce the snowpack more than the average summer. With typical late summer conditions mass balance will be -1.1 m on Easton Glacier. The Deming Glacier debris cover has now spread across the entire terminus, retreat from 1985 to 2014 is 480 m. The snowline was at 2075 m in early August in the main icefall, which is 100 m higher than normal.

Breakfast at camp below Easton Glacier

Jill Pelto assessing the depth of crevasses on Easton Glacier, her sixth year working on glaciers.

Determination of annual retained snowpack depth using crevasse stratigraphy.

More snowpack assessment by Ben Pelto and Justin Wright.

Ashley Edwards descending Easton Glacier lower icefall

Melanie Gajewski visually examining the Easton Glacier profile.

Mauri Pelto on a serac in Easton Glacier icefall, 31st year working on these glaciers.

The next stop was Helitrope Glacier on the north side of Mount Baker, where we installed of a stream gage below the Heliotrope Glacier. Oliver Grah and Jezra Beaulieu of the Nooksack Indian Tribe installed the gage while we calibrated runoff and assessed the amount of snowcover on the Heliotrope Glacier, the western extension of the Coleman Glacier, and installed ablation stakes. The rise in the snowline over the rest of the summer will identify the ablation of snowcover. The maximum snowpack on Heliotrope Glacier was less than 3.5 m, which means almost the entire glacier will lose snowpack by the end of September up to the ridge above it. The daily runoff from the Roosevelt-Coleman-Heliotrope system during our observations was an impressive 14 million cubic feet per day.The snowline was quite high on Roosevelt Glacier and Coleman Glacier at 2000 m in mid-August. The retreat of Roosevelt in particular is impressive since my first visit in 1985, a retreat has been 450 m over this interval.

Camp at Heliotrope Glacier.

Justin Wright on the Coleman Glacier

Oliver Grah installing stream gage below Heliotrope Glacier. Jill Pelto probing snowpack.

Continued warm dry weather led to records numbers of hikers at Artists Point as we headed out Ptarmigan Ridge on the northeast side of Mount Baker to work on Rainbow Glacier and Sholes Glacier. During our first day the east wind pushed forest fire smoke into the area eliminating views. We surveyed the mountain goat herds as usual seeing three herds and a total of more than 60 different goats. With the high temperatures and forest fire haze the number of iceworms emerging at sunset during our population count was also an all time low. Rainbow Glacier had snowpack that was 1.25 m below normal. With typical late summer conditions mass balance will be -1.5 m on Rainbow Glacier. Sholes Glacier already had 15% blue ice exposed, on August 7th. This had expanded to 25% by August 12th. This rapidly expanded to 50% by August 23rd, note Landsat comparison below. It will be 60% by the end of August and then likely close to 80% loss by the end of the summer. With typical late summer conditions mass balance will be -1.6 m on Sholes Glacier. Remember glaciers in this area need 60% snowcover at the end of the melt season to balance their frozen checkbook. On Sholes Glacier we completed 118 measurements of 2014 snowpack depth via probing in this relatively crevasse free glacier.
A herd of 48 mountain goats.

Snowpack probing on Sholes Glacier.

Looking at Sholes Glacier from outlet where stream gage is installed.

Sholes Glacier outlet with the clearer surface melt runoff versus the turbid basal meltwater stream.

Ashley Edwards measuring streamflow.

Landsat 8 iamges from 8/7/2014 and 8/23/2014-red line is boundary of bare blue glacier ice where the 2014 snowpack has been lost.

Jill Pelto sketching in camp.

Megan Pelto sketching in camp.

Jill’s field sketch of glacier runoff with Penstemon in foreground.

Megan’s field sketch of glacier input to rising sea level.

We then headed to Lower Curtis Glacier, on Shuksan where the rain gods had their turn. That night we had one of the top three heaviest rainstorms I have experienced during my 31 years and 600+ nights camping in the North Cascades. Totals by morning exceeded 4 inches. Rain continued lightly during the day, making for a foggy day on the glacier. The avalanche danger was too high due to the warm temperatures even with the rain to survey the terminus. The main basin of the glacier had limited areas with snowpack over 2.8 m, which is how much is needed in mid-August to survive to the end of the melt season. With typical late summer conditions mass balance will be -1.1 m on Lower Curtis Glacier
The forecast of a one day rain event was now extended to two more days. We hiked up to Blanca Lake in the rain, woke up in the rain, hiked to the glacier in the drizzle and completed our measurements. The rain returned during the hike around the lake to camp. Snowpack was low around the lake, on the trail in and seemingly everywhere but on the glacier. Strong avalanching made this the first glacier even close to average in its snowpack. Snowpack was low in the highest basin of the glacier that is not as heavily avalanche fed. With typical late summer conditions mass balance will be -0.6 m on Columbia Glacier. The warm weather was evident in the temperature of the water being much warmer than usual in the stream ford that is required to reach the glacier.
Annual layers of the Lower Curtis Glacier terminus.

Surface stream assessment, Ben Pelto

Ben Pelto in his tenth year working on the glaciers, fording stream in wet weather to access Columbia Glacier.

Snowpack on Columbia Glacier limited blue ice.

Blanca Lake and Columbia Glacier.

On Mount Daniel the first surprise was that Deep Lake had changed from the normal blue to a jade green. This was due to the heavy rain, even east of the crest, the previous three days, which also caused the Cle Elum River to be quite high, though the water was also warm. Having hiked passed this lake each of the last 30 years this is the first time it was not a deep blue color. It will be interesting to see how long it is until the color reverts to normal. We hiked up the Daniels Glacier to the main summit of Mount Daniel, then descended the Lynch Glacier before reascending the Lynch Glacier. Both glaciers had below normal snowpack and considerable blue ice exposure. With typical late summer conditions mass balance will be -1.2 m on Lynch Glacier and -1.1 m on Daniels Glacier. Neither glacier receives much avalanche snow. The following day on Ice Worm Glacier snowpack was above normal on the lower half of this small glacier, clearly because of unusually large amounts of avalanche accumulation. The top half of the glacier had 1-2 m of snowpack that will be lost by mid-September. With typical late summer conditions mass balance will be -0.5 m on Ice Worm Glacier
View down the Lynch Glacier.

Daniels Glacier vieww

Ice Worm Glacier viewed across terminus melt pond

Marmot near camp.

Overall North Cascade glaciers will lose considerable volume. The volume lost is less on glaciers in the southern portion of the range and those with high percentages of avalanche accumulation.

Easton Glacier profile.

Easton Glacier icefall

Melanie Gajewski and Megan Pelto below icefall.

Hollentalferner Retreat, Bavarian Alps Germany

On August 26, 2014 By mspeltoIn Glacier Observations

Hollentalferner (Glacier) is on the east flank of Zugspitze the highest mountain in the Bavarian Alps of Germany. The upper portion of the glacier is avalanche fed which flows through a minor icefall to the main terminus tongue that displays prominent annual layers.Hagg et al (2012) in a detailed examination of Bavarian Alp glaciers report on changes in the area of this glacier from 1950 to 2010. They note that from 1959 to 1981 the glacier expanded from 26 to 30 hectares. From 1989 to 2010 the glacier contracted from 30 hectares to 22 hectares. A comparison of 2000 and 2009 Google earth images indicates a retreat of the main terminus tongue of 40 m. The glacier tongue also contracted a similar amount in width. The level of crevassing on the upper glacier declined somewhat. In a closeup of the annual layers, last image, the main tongue displays 45 annual layers, red arrows. The secondary terminus, pink arrow, displays much narrower and more numerous layers. The supraglacial streams, orange arrows have incised more deeply into the glacier from 2000 to 2009. The combination of retraction of the terminus tongue, reduced crevassing and greater surface stream development on the glacier indicate a thinning glacier that will continue to slowly retreat. The crevasses in the icefall reach, green arrows, have significant depth ~10 m, and are widened by ablation processes. They indicate active flow from the upper glacier in the recent past, but the sharply concave profile below the icefall suggests limited flow into the terminus tongue area at present. The glacier retreat is less than on Blaueis Gletscher and though the glacier cannot achieve equilibrium with current climate and will disappear, this process will take longer than on the other Bavarian glaciers, this glacier will almost certainly still be around after 2030.
Image from Karlsruhe Institute of Technology

Table of areal extent change from Hagg et al (2012)

Google Earth 2000

Google Earth 2009

Blaueis Gletscher Retreat, Bavaria Germany

On August 22, 2014August 22, 2014 By mspeltoIn Glacier Observations1 Comment

The Blaueis Gletscher is the furthest north glacier in the Alps. It occupies a narrow deep valley oriented north, between the summits of Blaueisspitze and Hochkalter. Hagg et al (2012) in an examination of Bavarian glaciers over the last 120 years note the changes in area of Blaueis Gletscher. The glacier increased in area from 16 to 20 hectares during the 1889 to 1924. Retreat from 1924 to 1970 led to a decrease in area to 12.6 hectares. Advance in the 1970’s increased the area back to 16 hectares by 1980. Since 1980 rapid area loss to 7.5 hectares by 2009. This rapid loss has led to many media reports of the imminent loss of the glacier. Here we examine imagery of the glacier from 1982-2014 to identify its current status. In 1982 the glacier consisted of the main upper reach and a thin lower ice in a photograph from R. Drescher from the Bayerische Gletscher website. By 2005 the thin lower ice has declined in area and thickness and is not connected to the upper glacier allowing ice transfer. There is some fringing thinner ice in 2005 on the lower margin of the upper ice. By 2009 the thin marginal ice at the downhill end of the upper glacier, has declined and become largely detached from the main glacier. A closeup in 2009 indicates the glacier has 45-48 annual layers of accumulation exposed at the glacier surface. This image indicates that no recent accumulation has been retained as all of the layers are blue ice and no snow or recent firn exists on the upper glacier. A glacier without consistent accumulation cannot survive (Pelto, 2010). This survival forecast method does not detail how long it will take to disappear. The number of annual layers exposed indicates the glacier thickness is still significant, further the location precludes rapid melt. Thickness maps from 2007, from the Bayerische Gletscher group, indicate the main upper ice is 5-10 m thick, with some areas over 10 m thick, based on radio echo sounding. Based on the number of annual layers and lack of crevassing reaching the glacier base, it seems to me the average thickness is somewhat greater. Glacier’s that I have worked on develop significant crevasses that reach the glacier base as the thickness drops below 10 m. Using typical volume-area scaling coefficients suggest the average thickness to be 12-15 m. There is a webcam at the Blaueis Hut that indicates the glacier today 8/22/2014 still has substantial snowcover. With the current climate this glacier in the least exposed niche on the mountain should be able to endure more than a decade.

Data from Hagg et al (2012)