Posts Tagged glacier mass balance

Pacific Northwest Glacier Mass Balance 2013

North Cascades Climate Conditions:
The 2013 winter accumulation season featured 93% of mean (1984-2013) winter snow accumulation at the long term USDA Snotel stations in the North Cascades, Washington (Figure 1). The melt season was exceptional by several measures. The mean summer temperature from June-September and July-September at Lyman Lake is tied with the highest for the 1989-2013 period (Figure 2). The average minimum temperature at Lyman Lake was the highest since 1989 for the July-September period, and tied with the highest for the June-September period (Figure 3). SeaTac airport minimums were high as well indicating the regional nature.

Glacier Mass Balance:
Snow depth was measured at a 30 m spacing across the entire glacier on August 4th. The position of the snowline indicates the location where snow depth is zero. Assessment of stakes emplaced in the glacier from Aug. 3-20 indicates mean ablation during the period of 7.8 cm/day. Assessment of ablation from remapping of the snowline on Sept. 1 indicates mean ablation of 7.5 cm/day during the August 4th-Sept. 1st period. A preliminary map of Sholes Glacier mass balance for Aug. 8th is seen below (Figure 6). The contours are in meters of water equivalent, which is the amount of water thickness that would be generated if the snow or ice was melted. Note the similarity of the 1.75 m contour and the Sept,. 12th snowline.The best measure of ablation over the period from August 4th to Sept. 12th is the shift in the snowline, as identified in satellite imagery (Figure 7 and 8). The snow depth at a particular location of the snowline on Sept. 12th indicates the snow ablation since August 4th. Observations of the snowline margin on Aug. 20, Sept. 1 and Sept. 12 indicated mean ablation of 7.4 cm per day from Aug. 4th to Sept. 12th.

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Figure 4 Comparison of snowpack on Sholes Glacier on August 4th and September 1st, 2013

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Figure 5. Sholes Glacier snow depth measurement network

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Figure 6. Snow depth distribution in snow water equivalent on Sholes Glacier on Aug. 8th, 2013.

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Figure 7 August 4th satellite image showing snowline on Sholes Glacier from Landsat imagery.

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Figure 8. September 12 snowline on Sholes Glacier from Landsat imagery

Snow depth observations on Easton Glacier on the bench below the main icefall at 2000 m, yielded an average depth of 3.1 m on Aug. 10th. The bench was completely snowcovered on Aug. 10th. GPS measurements of the snowline on Sept. 15th indicate ablation of 2.75 m since Aug. 10th. This is an ablation rate of 7.6 cm of snow melt per day. This is 0.2 cm/day higher than Sholes Glacier. The time period is not identical either. The southern orientation of Easton Glacier typically leads to higher ablation rates at specific elevations than on Sholes Glacier. Satellite observations of the change in snowline position compared to snow depth observations from Aug. 4th to Sept 12th indicate mean ablation of 7.2-8.0 cm/day.

On the four Mount Baker glaciers a total of 380 snow depth measurements were made on (Figure 9). The initial mass balance assessment is -0.78 m on Columbia Glacier. -1.58 m on Easton Glacier, -0.5 m on Foss Glacier, -0.76 m Ice Worm, -0.85 m on Lower Curtis Glacier, -0.40 m Lynch Glacier, -1.85 m on Rainbow Glacier, -1.7 m on Sholes Glacier and -1.15 m on Yawning Glacier. easton crevasse depth
Figure 9 Snow depth in crevasse on Easton Glacier.

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Figure 10 Mass balance map for Columbia Glacier in meters of water equivalent.

On the Juneau Icefield in southeast Alaska the ablation season was warmer and longer than normal. The result was snowlines rising above average at Lemon Creek and Taku Glacier, where the Juneau Icefield Research Program measures mass balance. For Taku Glacier the ELA was 1050 m, 75 m above an equilibrium snowline, and 1115 m, 100 m above an equilibrium snowline for Lemon Creek Glacier. The final mass balance for these glaciers will be in the -0.5 to -1.0 m range for both. Further north the USGS reports preliminary results, from there two Alaskan benchmark glaciers, which indicate that Gulkana Glacier in the Alaska Range, mass balance was the 5th most negative year. At Wolverine Glacier in the Kenai Mountains mass balance will likely be the most negative on record. In British Columbia both the Helm Glacier and Place Glacier are observed annually for mass balance. On Sept 12, 2013 Landsat imagery indicates limited remaining snowcover on both of these glaciers. The snowline is at 2050 m on Helm Glacier and 2300 m on Place Glacier, red arrows. The snowcovered area is less than 20% on Helm Glacier and 30% on Place Glacier, which will lead to large negative mass balances (Figure 11 and 12). Hence, all 16 glaciers examined here will have significant negative mass balances in 2013.

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Figure 11. Landsat image indicating the snowline on Sept. 24, 2013 on Lemon Creek and Taku Glacier.

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Figure 12 Helm Glacier in Landsat imagery 9-12-2013

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Figure 13 Place Glacier in Landsat imagery 9-12-2013

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Building a 30-year Glacier Mass Balance Time Series

The above video looks at the effort behind a long term field study, looking at images from 11 of the 30 years of our research, digital cameras became good then. Long term monitoring programs have until recently been unattractive for federal grantmakers, since they are not directly advancing the frontiers of science. However, many long duration time series from monitoring programs do advance science eventually as the response to changes in environmental or climate conditions are documented. In 1984, I responded to a request from the US National Academy of Sciences, “to monitor glaciers across an ice clad mountain range”, something that was not being done anywhere in Norther America. Thirty years later we are still pursuing this project. We have developed a 30 years time series of glacier mass balance on glaciers across the North Cascades of Washington. To ensure that the program could be sustained, we did not pursue any federal funding for the project. The data we, collect is submitted to the World Glacier Monitoring Service (WGMS) each year, the regional time series built in the North Cascade is just part of the contribution to the global glacier mass balance time series at WGMS. The cumulative North Cascades glacier mass balance record is in fact quite similar to the cumulative global mass balance time series. For the globe there have been 22 consecutive years of negative mass balance, that is the reality of the impact of global warming on mountain glaciers around the globe. The impact on the glaciers of Mount Baker was recently published Pelto and Brown (2012)
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North Cascade Glacier Climate Project 2013 Field Report

The 2013 winter season provided close to average snowpack in the North Cascades as indicated by the average SWE at SNOtel stations in the range. The summer melt season has proved to be long, warm and dry. The May-August mean temperature at the station closest to a glacier, Lyman Lake, has been tied for the 2nd warmest in the last 25 years with 2009 and only 2004 warmer. The summer has lacked record periods of warmth and has featured sustained warm temperatures and higher than average humidity, reducing the number of nights when the glacier surface has frozen. The average minimum temperatures at Lyman Lake are the highest in the last 25 years for July and August. The humidity was the strikingly high during our field season, note diagram from a Cliff Mass article on the topic. The net result will be significant negative glacier mass balances in the North Cascades. There is one month left in the melt season most glaciers are close to an equilibrium balance already.

The field team included Stewart Willis and Matt Holland, Western Washington University, Jill Pelto, U of Maine, Ben Pelto, UMass,-Amherst, Jezra Beaulieu and Oliver Grah, Nooksack Indian Tribe research scientists And Tom Hammond, North Cascade Conservation Council. Alan Kearney, Photographer worked with us for the first week capturing time lapse imagery of our work.

After a month of perfect summer weather we arrived to a foggy and wet conditions on the Columbia Glacier. The Columbia Glacier terminus was exposed and has retreated 85 m since 1990. The glacier had a substantial area of blue beginning 200 m above the terminus and extending along the western side of the basin for 400 m. The area of blue ice on August 1 was 50,000 square meters, by Aug. 21 the area had expanded to 200,000 square meters, the shift of the 2013 winter snowline during this period indicates a melt of m during the three weeks.


The Lower Curtis Glacier terminus was exposed early in the summer resulting in a continued retreat of 20 m since 2011, the area of thick seraced terminus lost since 1990 has been 60,000 square meters. The lateral retreat and terminus retreat since 1990 are both in the 125-150 meter range depending on location.
We spent a week observing ablation and resulting glacier runoff on Sholes Glacier. With Oliver Grah and Jezra Beaulieu who work for the water resources section of the Nooksack Indian Tribe we emplaced a stream gage right below Sholes Glacier and one on Bagley Creek which is snowmelt dominated. With the water level gages in we all began work on a rating curve for the Sholes Glacier site directly measuring discharge on 14 occasions, kayak socks helped reduce the impact of cold water. Average ablation during the week was 8.25 cm/day of snowpack or 5 cm of water, discharge measurements identified a mean of 5.2 cm/day of from the glacier during this period. The agreement between ablation and discharge was a nice result. Discharge became notably more turbid after 1 pm, peaking in turbidity around 5 pm. Of equal interest was the change in snowcovered area. On July 19th a Landsat image indicated 100% snowcover for Sholes Glacier. On Aug. 4th our surface measurements indicates a blue ice area of 12,500 square meters, which is also evident in a Landsat image from that day. By Aug. 20th a satellite image indicates that the blue ice area had expanded to an area of square meters. This coincided with the area where snowdepth was observed to be less than 1.2 m on Aug.4. This represents a volume loss of 592,000 cubic meters of water in 16 days.
We measured the mass balance on Rainbow and Sholes Glacier during this period. The snowpack was poor on both, especially above 1900 meters on Rainbow Glacier. Typical depths are over 5-6 m, this year 3.75-4.5 m. The poor snow depths were also noted on the Easton Glacier above 2000 m in crevasse stratigraphy measurements. Each crevasse is approached probing to ensure it is safe and then assessed to make sure the crevasse is vertically walled, this enables a safe but also accurate measure. In some cases layers from mulitple years can be assessed. IN the Lynch Glacier crevasse the 2013 layer will be lost to melt before end of the summer. Easton Glacier had a terminus that was fully exposed by the start of August. The terminus slope has thinned markedly in the last three years as retreat has continued. The retreat of Easton Glacier has averaged 10 m/year from 2009-2013. This year the retreat will exceed that with two months of exposure. The Deming Glacier retreat has been exceptional over the last 12 months with at least 30 m of retreat. The snowline on Easton Glacier was at 1850 m on Aug. 10th. By the end of August the snowline had risen to 1980 m, where snow depths had been 1.5 m three weeks previous. The mass balance of Sholes, Rainbow and Easton Glacier will all be close to – 1 meters water equivalent, that is losing a slice of glacier 1.1-1.2 m thick. Mount Daniels had the best snowpack of any location in the North Cascades. On the small and dying Ice Worm Glacier ablation and runoff were assessed simultaneously. The expansion of the area where 2013 has all melted expanded rapidly from 8/13 to 8/21. The glaciers lower section had is often avalanche buried, this year the snowpack was gone on much of the lower section. However, snowpack averaged 1.7 m across the entire glacier on August 14th. With daily ablation of 7-8 cm/day this will be gone by early September. This will lead to a substantial negative mass balance this year. Lynch and Daniels Glacier both had limited exposed blue ice and firn, and snowpack values that were slightly above average. Both glaciers will have small negative mass balances this year. On Lynch Glacier a large crevasse at exposed the retained snowpack of the last three years, from 2010-2012 5 m of firn remains. ice worm 2013

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Ben in his 9th year, Jill her 5th year and Mauri 30th year of glacier work in the North Cascades

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Mittivakkat, Greenland and Lemon Creek Glacier, Alaska transient snowline paper

Mernild et al (2013) is a new paper that has authors from several countries that I am co-author on with Knudsen, Malmros in Denmark, Hanna from UK, Yde currently in Norway and Mernild in Chile. The key items here are using the snow line observed on any particular melt season day (transient snowline=TSL) as input for mass balance assessment. This paper examines how similar the migration of the TSL is from year to year, and how ablation rate can be determined using it, when field data can be used for validation. The first two images are figures from the paper of Lemon Creek Glacier and Mittivakkat Glacier illustrating the TSL at various dates. A second key is that if the progression is relatively repeatable towards the end of the melt season, than the equilibrium line altitude (ELA) can be determined, snowline at the end of the melt season, which is a key mass balance variable. Clouds often obscure the ELA from satellite image assessment, and this allows appropriate extrapolation. The figure below needs more data to determine the consistency and nature of the TSL variation at the end of the melt season, the ELA is the top of the parabola. lemon creek base map4
Base map of Lemon Creek Glacier in 2003 with colored lines indicating various dates of the TSL.

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Base map of Miitivakkat Glacier in 2012 with colored lines indicating various dates of the TSL.

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Progression of the TSL approximated with a second order Polynomial, to help derive the ELA.

A good example of the utility is an examination of the Landsat 8 imagery from this summer. Alaska had a warm and relatively clear weather period that provided a rare chance to examine the TSL in three consecutive satellite passes on June 14, June 21 and June 30. This period began with the glacier almost completely snow covered, red dots indicate TSL, red arrow indicates the 6/30 TSL. On June 14 the TSL was at 775 m within a couple of hundred meters of the terminus. By 6/21 the TSl had moved up the northwest side of the glacier 1.5 km to an altitude of 900m. On June 30th the TSL was at 975m two kilometers from the terminus. This progression up the northwest side of the glacier is typical. At the start of July the glacier is still 90% snowcovered. The Juneau Icefield Research Program is on this glacier in early July and field work will be critical to identifying snow depths above the TSL, that the TSL will transect later in the summer identifying ablation. The yellow arrow indicates the formation of Lake Linda, a meltwater lake that forms on the glacier, the expansion from June 14 to June 30 is evident. Pictures of the lake from JIRP during self arrest practice are gorgeous. More detailed examination of the longer term change of Lemon Creek Glacier and Mittivakkat Glacier has been completed.lemon creek 165-2013
June 14 2013 Landsat image

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June 21 2013 Landsat image

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June 30 2013 Landsat image

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Mass balance 2011 North Cascades, Washington and Juneau Icefield, Alaska

In the summer of 2011, the North Cascade Glacier Climate Project completed 430 measurements of snowpack on 10 glaciers using probing and crevasse stratigraphy. This is much less than our normal number because of the exceptionally deep snowpack. The probe we use was 5 meters long, beyond that only crevasses could be used. The mass balance was quite positive for the first time since 2002. The combination of a La Nina and a negative PDO almost always deliver a mass balance in the North Cascades, 9 of 11 times (Pelto, 2008). The March-May period was the coldest and wettest spring ever in the North Cascade region. Summer was also cool in the region. This led to positive balances ranging from +1.2 to +2.2 m, the first year with significant mass balance since 1999. The first image below is the preliminary mass balance map for the Lynch Glacier in 2011, indicating the measurement points, black dots, and the blue contour line is the snowline. The cumulative mass loss since 1984 is still 12 meters, or 20-30% of the total volume of these glaciers, second image below. . Below is the field season captured in images.

Fourteen hundred kilometers north the Juneau Icefield glaciers did not fare as well. As part of the Juneau Icefield Research Program mass balance measurements are made every summer on the Taku and Lemon Creek glaciers. This summer the program was headed by Jay Fleisher, the mass balance portion was spearheaded by Chris McNeil and Toby Dittrich, Portland Community College. Satellite imagery from Sept. 11, 2011 indicates the snowline at the end of the melt season was just over 1000 meters on Taku Glacier and nearly 1100 meters on Lemon Creek Glaciers. This is higher than average and indicates negative mass balances for both glaciers. Snowpit and probing measurements at 40 locations, will yield a more specific mass balance, than provided by the snowline. The snowline is quite similar to 2009 and 2010 with snowpack depths generally a bit lower, 2009 and 2010 were also negative mass balance years. The snowpits are typically 2-4 meters deep and quite an effort to dig, the image below is from Cathy Connor at University of Alaska Southeast. The cumulative mass balance loss since 1953 on Lemon Creek Glacier is 25 meters, 15 meters since 1984.

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28th Field Season of the North Cascade Glacier Climate Project 8-1 to 8-20

During the interval of 8-1 to 8-20 there will be no blog updates, we will be in the field for the entire period. This is the 28th consecutive year we will monitoring the terminus behavior and mass balance of these glaciers identifying how they respond to climate change. In these 28 years all the glaciers have retreated significantly they have lost 20% of their volume and two of the glaciers we monitored every year have disappeared.
If you are in need of glacier observations, please take a look back at the index of 100+ posts to date
Or look at the video footage below from the 2010 field season and the 2009 field season

North Cascades Glacier Documentary Promo 2010 from Cory Kelley on Vimeo.


2009 field season video

We begin the field season on Columbia Glacier near Monte Cristo, WA.
We will then head north to the Lower Curtis Glacier on Mount Shuksan. A traverse west will takes us to Sholes and Rainbow Glacier on the ne side of Mount Baker.

We will then drive around Mount Baker and examine the Easton, Deming, Squak, Talum and Boulder Glaciers on the south and east side of Mount Baker.

We then head to Cache Col Glacier near Cascade Pass and finally south to Mount Daniels for Ice Worm, Daniels and Lynch Glacierto finish the field season. It was a historically cool and wet spring and the glaciers still have a thick blanket of snowcover. How thick is what we will be measuring one glacier at a time.

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North Cascade Glacier Mass Balance 2010

A glacier has no memory of the past year when it comes to mass balance, unlike say the extent of sea ice, it is more like the extent of snowcover. This was emphasized by a comparison of glacier mass balance in the North Cascades from 2009 to 2010. Temperature sensitivity is also highest during the summer for a glacier and for snowcover in general. As the melt season begins the snow cover extent is large on a glacier-100% for North Cascade glaciers. The key is how rapidly the snow line rises during the melt season. For continental scale snowcover it is more of a recession northward. In the Northern Hemisphere for example February 2010 was the third most extensive snow cover extent of the last 44 years, March the 18th of the last 44 years, and April the 41st most of the last 44 years, in the Northern Hemisphere and the 44th most extensive in North America. (Rutgers University Global Snow Lab). This change indicates a record snow cover melt off in 2010 for the last 44 years. This was not surprising given that global temperatures anomalies were also at there highest levels during this period. This can happen on a glacier as well. For North America the main change with global warming is the decrease in melt season snow cover extent as noted in the image below, which shows red for well below average snowpack, and dark blue well above average snowpack. Note the dark blue nature of summer in the 1970′s and the dark red in the summers after 2003. t is during the summer when temperature alone is the key, not storm tracks and jet stream position. . For the North Cascades the summer melt season of 2009 was the record, not 2010. North Cascade glaciers over the 27 years I have been monitoring them. I
For the North Cascades In 2009 a negative PDO (Pacific Decadal Oscillation) and negative ENSO (La Nina) existed leading to below normal temperatures and average precipitation during the winter in the Pacific Northwest. The combination of a negative PDO and a negative or equilibrium La Nina has led to an equilibrium or positive glacier mass balance in the North Cascades, WA in 13 of 16 years since 1960. The summer of 2009 had the highest total ablation recorded during annual mass balance measurements since 1984, offsetting good winter snowpack and leading to a mean negative mass balance of -1.9 m. In 2010 a positive PDO and ENSO (El Nino) conditions persisted during the winter leading to above normal temperatures and average precipitation in the Pacific Northwest. The combination of a positive PDO and El Nino has led to negative glacier balance in all 14 years this has occurred since 1960. A markedly cool 2010 melt season led to near minimum ablation since 1984, and an equilibrium mean annual balance of 0.05 m. Ablation season conditions dominated the mass balance record for both years. In 2009 there was a transition from a La Nina to an El Nino accompanied by a change to a postiive PDO. In 2010 a change from an El Nino to a La Nina and to a negative PDO. We will be exploring the impact of coastal upwelling strength, upwelling onset, PDO, ENSO and the Pacific Transition for these two unusual summer seasons. In 2009 a high pressure ridge was centered over the West Coast, upwelling began early and there was limited marine influence along the coast. In 2010 an anomalous high pressure center in the eastern North Pacific generated northerly winds along the West Coast and a late onset of upwelling. Our goal is to be able to forecast the summer melt season conditions sometime in May. A comparison of the mass balance maps for Columbia Glacier in 2009 and 2010 illustrates the difference The lines are contours of mass balance ochre is the zero balance line as of August 1, then brown-red 1 m of snowpack, blue, two meters and green three meters, than lime green is the end of summer snow line. Note that as of Aug. 1 both years had nearly identical snowpack, but ablation was much higher due to record warmth in August 2009, and the snowline ended much higher than in 2010. The result despite less winter snowpack, a more positive though still negative mass balance for Columbia Glacier in 2010. In the summer of 2010 we measured the snow depth and/or snow melt at 180 locations on this glacier. The Columbia Glacier is a low elevation glacier mostly below 5200 feet. It is also avalanche fed. Both factors led to abnormally low snow accumulation in the winter of 2010, and despite the cool summer a negative balance. Easton Glacier on Mount Baker on the other hand is mostly above 6000 feet, and does not receive avalanche accumulation. The winter snowpack was close to normal and then below normal melting led to a positive mass balance. The glacier gained an average thickness of 0.7 meters. This is small compared to the loss of 2 meters.

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Rainbow Glacier Mass Balance

In 2010 at the end of a four day period of cool rainy weather we hiked into to our base camp on Ptarmigan Ridge to measure the mass balance of the Rainbow Glacier on Mount Baker in the North Cascades of Washington for the 27th consecutive year. Below is a view of Rainbow Glacier as we approach it. This is a valley glacier that begins on the slopes of Mount Baker at 2200 m and descends to a terminus that is often avalanche covered at 1350 m. The year proved to be the most variable in terms of glacier mass balance of any of our 27 years. Assessing the mass balance requires melting the extent and depth of snowpack on the glacier. We had a chance to measure the snow depth in 121 locations using crevasse stratigraphy and probing. The below image has all of the measurement locations, blue dots, and the rough contours of mass balance marking the snowline in green-blue, the 1 meter of snowpack water equivalent (swe) in purple and the 2 m of swe in blue. Glacier margin is in orange-brown.. The initial field assessment of mass balance for the Rainbow Glacier in 2010 was +0.81 m. At this time the significant melt season is at an end, new snow is projected for tomorrow 9/23. The average over the previous 26 years has been -0.40 m/year. Of the ten glaciers we monitor there was a split with six having negative balances and four positive, the variation is unusual. The probe is a half inch diameter steel rod that is easily driven through the snowpack until the hard icy layer marking last years summer surface is reached. This can either be bare glacier ice or the firn from the previous year. In either case it cannot be penetrated. The second means is to lower a tape measure down the wall of a vertically sided crevasse. This provides a two dimensional measure and view of snow depth versus the point measurement of probing. By late summer the density of the snowpack is uniform in the North Cascades. We survey the blue ice regions using a GPS to map the boundaries. Melting is assessed by observing the progressive ablation of snow and ice. On Rainbow Glacier snowpack was normal below 1800 m, where probing is dominantly used. The snowline was at 1450 m in early August and had risen to 1600 m by late September. Above 1600 m the snowpack increased very rapidly this year from 1.5 m at 1800 m to 5.5 m at 2100 m. This reflects the unusually warm winter that led to a dearth of snow below 1800 m by winters end. Above this elevation several winter events that were rain below were snow. Than melting was well below normal in the summer of 2010. Again spring snow storms retarded melt above 1800 m, while those were rain events below this elevation.
Crevasse stratigraphy was the dominant tool of measuring snowpack on the Rainbow up to is divide with Mazama Glacier. Navigating these crevasses takes considerable care using the snow probe as a crevasse probe. . The area of bare glacier ice is riven by some large streams, which are also the focus of annual observation. T The terminus this summer was buried in snow from an avalanche, as was the case last year. In 2007 the terminus was fully exposed and we could measure the retreat at 450 m in the last 25 years. This glacier’s mass balance history follows that of the other northwestern North American glaciers which also is right in line with global mass balance. All data is from the WGMS. One of the best parts of this location is the gorgeous campsite we use for a base camp. It is above the glacier so we have to hike uphill at the end of the day. . his area is noted for its mountain goats as well which we count annually. We will complete a final analysis in the next month and report this data to the World Glacier Monitoring Service.

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North Cascade Glacier Climate Project 27th field season 2010 starts Aug. 1

For the next three weeks I will be in the North Cascades of Washington visiting and measuring snowpack, snow melt and area change on North Cascade glaciers. There will be no new posts here during this period. Though you can take a look at the film documentary crews site travelling with us. Our main task is assessing glacier mass balance on 10 glaciers which are then reported to the World Glacier Monitoring Service (WGMS). We measure the snowpack by probing through it to the previous summer’s impenetrable surface, due to melting and refreezing or being blue glacier ice. The other means is examining snow depth in a crevasse using the evident stratigraphy. We monitor the snow melt and reset stakes in the glacier to monitor the snow melt as well. We also measure changes in surface elevation and margins of the glacier. We will report back shortly after our return on the status of these climate sensitive glaciers.

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Rembesdalsskaka, Norway Current Retreat

The Hardangerjøkulen Ice Cap is situated in southern Norway,150 km from the western coast. This elliptical shaped ice cap covers 73 square kilometers and ranges in altitude from 1020 to 1865 meters. It rises above the community of Finse offering access to snow year around. Norway has the most comprehensive glacier monitoring program in the world, mainly due to the heavy reliance on hydropower, for which glacier runoff is a key input. The Rembesdalsskaka drains west from the ice cap, the left side feeding the Rembesdalsvatnet Reservoir. The research is led by the The Norwegian Water Resources and Energy Directorate (NVE). Statkraft runs the Sima power station that is fed from Rembesdalsvatnet Reservoir and the larger Sysenvatn fed by the southern glaciers of Hardanger. This system produces 620 Mw of hydropower. The largest glacier draining the western side of the ice cap is the Rembesdalsskaka with an area of 17 square kilometers. Since the LIA maximum Rembesdalsskaka has retreated almost two kilometres, The ice cap decreased in volume from the Little ice Age until 1917, followed by an increase in ice cap volume and glacial advance until 1928, . After this a period with high negative mass balances cause a rapid retreat of Hardangerjøkulen until 1950. Retreat continued until 1961, but the rate declined. From 1961 to 1995 mass balances increased, with the highest balances in the late 1980’s and early 1990’s. This resulted in an advance of Rembesdalsskaka. Since the early 1990’s mass balance has been negative, with exceptionally negative years in. This has led to the retreat of the Rembesdalsskaka each year from 2000-2009 a total of 307 meters. The retreat is measured each year from a benchmark painted on rock beyond the terminus, reported to the NVE and then to the World Glacier Monitoring Service. In 2009 the NVE reported 19 glaciers retreated, 3 were stationary and one advanced.

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Mass Balance of the Easton Glacier 2009

Immediately below is Easton Glacier on Mt. Baker in the North Cascades in late May 2009. The glacier is still completely snow covered. The bench where the small gray cloud shadows are at 6000 feet averages 20 feet of snow remaining.
easton 5-20-09 (1)Easton Glacier extends from the terminus at 5600 feet to the slopes near Sherman Crater at 9000 feet. Each summer since 1990 NCGCP has measured the mass balance of this glacier. View Youtube for a pictorial review of the full 2009 field season . The glacier has retreated 300 m since 1990. During this same period the glacier has lost a cumulative mean of 13 m of thickness. Given a thickness in 1990 between 60 and 75 m, this is about 20 % of the total glacier volume. The image below shows the terminus in 2009(green=2009, 2006=brown, red=2003, purple=1993 and yellow=1984). Measuring mass balance requires assessing snowpack depth and areal extent at the end of the summer melt season and the amount of melting in areas where blue ice or firn (snow more than a year old) is exposed. Below is measuring crevasse stratigraphy and below that emplacing a stake to measure ablation with weather instruments on it. f25f18

Mass Balance = residual snow accumulation – ice-firn melting.

The melt season began a bit late just when the May picture was taken Winter snowpack was between 75and 90% of normal in the area as of April 1. The melt season had been late to begin and snowpack by late May was near normal. Record heat was experienced at the end of May and the start of June, quickly causing snowpack to fall below normal.Each year we measure the snow depth via probing and crevasse stratigraphy at more than 200 locations. These depth measurements allow the completion of a map of snow distribution. This map is completed in early August and updated, based on a smaller number of observation in late September. The amount of melting is assessed from stakes emplaced in the glacier and the recession of the snowline in areas where snow pack depth has been assessed. below are images from early and then mid-August indicating the rise of the snowline. DSC02239easton8-16-09
A warm June and July caused exceptional snow pack melt and by early August when we began assessing snow pack depth retained, the snowcover had receded to the 6400 foot level, 300-400 feet higher than normal. Snowpack remained below normal all the way to the 8600 foot level. the snowpack since early July had been rising nearly 100 feet per week. By mid-August at right the snow line on the glacier averaged 6800 feet. By mid and Late September the snowline had risen to 7400 feet a rate of rise of 150 feet per week since mid-August. Below is an image from mid-September 2009. The amount of melting on the glacier in July was the highest we have measured totaling, 2.1 m. This led to the exposure of a couple of new bedrock knobs evident in the picture at right near the 2100 meters, black arrows. Overall the mass balance of the glacier in 2009 was a negative 2.06 m. This glacier averages 55-70 m in thickness and this mass balance loss represents a 3% volume loss in a single year for the glacier.

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Columbia Glacier year by year

The following pictures give a year by year view of Columbia Glacier within one day of August 1. The best year was 1999, the worst, 2005.The snowy peaks of the Monte Cristo region can be seen from the Everett area. With 30 glaciers many at low altitudes, this region may receive more snow than any other region in the North Cascades. The largest and lowest is Columbia Glacier occupying a deep cirque above Blanca Lake and ranging in altitude from 4600 to 5700 feet. Kyes, Monte Cristo and Columbia Peak surround the glacier with summits over 2000 feet above the glacier. The Monte Cristo range is the first major rise that weather systems coming off the ocean encounter on the way east to the Cascade Crest. As a result precipitation is heavy. During the summer if it is raining anywhere in the North Cascades it will be in the Monte Cristo region. The glacier is the beneficiary of heavy orographic lifting over the surrounding peaks, and heavy avalanching off the same peaks. We measure the mass balance of this glacier each year and report the data to the World Glacier Monitoring Service. The location is gorgeous as seen in this painting by Jill Pelto Despite the advantages of snow accumulation the glaciers mass balance since 1984 has average -0.5 m a year for a cumulative loss of 13 m. For a glacier that averages 60 m in thickness this is over 20% of its volume. Details of the mass balance research and methods are at

Columbia Glacier has retreated 134 m since 1984. Lateral reduction in glacier width of 95 m in the lower section of the glacier and the reduction in glacier thickness are even more substantial as a percentage. The major issue is that the glacier is thinning as appreciably in the accumulation zone in the upper cirque basin as at the terminus. This indicates a glaciers that is in disequilibrium with current climate and will melt away with a continuation of the current warm conditions. The glacier has lost 17 m in thickness since 1984, but still remains a thick glacier, over 75 meters in the upper basin and will not disappear quickly.

A lateral moraine deposited during the Little Ice Age, is visible at the western edge of the glacier, descending below the glacier to 4250 feet. This moraine has little vegetation on the inside, but is vegetated on the outside. Just in front of the terminus are two terminal moraines deposited during retreat in the last 20 years. Facing southeast Columbia Glacier is protected from any afternoon sun except during the summer. During the winters storm winds sweep from the west across Monte Cristo Pass dropping snow in the lee on Columbia Glacier. Avalanches spilling from the mountains above descend onto and spread across Columbia Glacier. The avalanche fans created by the settled avalanche snows are 20 feet deep even late in the summer. Nearly a third of the glacier is covered by avalanche fans, but no summer avalanches have been observed. Avalanches, shading from the sum provided by the high peaks, and wind drift snow deposition permits Columbia Glacier to exist at such a low altitude.

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