[peltoms]

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 was the highest in the last 25 years for July and August.

April 1 SWE at Snotel sites in North Cascades

The field team for our 30th season 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. <a href="http://www.alankearney.com/">Alan Kearney, Photographer</a> worked with for the first week capturing time lapse imagery of our work. Then there are NWHikers who take useful pics like Stefan-K of Columbia Glacier and hopefully other as the summer progresses. 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. 18 the area had expanded to 200,000 square meters (Stefan_K), the shift of the 2013 winter snowline during this period indicates a melt of m during the three weeks.

Columbia Glacier on Aug. 18 original taken by NWhiker Stefan-K

Columbia Glacier on Aug. 1

Columbia Glacier terminus

Columbia Glacier terminus

Surevying terminus of Columbia Glacier

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 meters range depending on location.

Terminus retreat Lower Curtis Glacier

Terminus of Lower Curtis Glacier

Matt Holland at terminus of Lower Curtis Glacier

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. NASA focused on this report we made.

Stream flow gage below Sholes Glacier

Stream flowing measuring location below Sholes Glacier

Landsat images of Mount Baker and Sholes Glacier

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 snow depth

Stratigraphy at 200 m on Easton Glacier

Measuring total crevasse depth with cam line.

Probing for crevasse

Snow depths in crevasse on Lynch Glacier

Measuring snow depth in crevasse on Rainbow Glacier

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.[gallery ids="6129,6146,6145,6138,6128,6127"] 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.

Retreat of Easton Glacier

Sketch of Easton Glacier camp by Jill Pelto

Easton Glacier terminus

Deming Glacier from above

David Tucker image of terminus of Deming Glacier

Amidst Eastson Glacier icefall

Easton Glacier near terminus

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 avalanched 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.

Squaw Lake Fairy house

Snow depths in crevasse on Lynch Glacier

Ice Worm Glacier on 8/21

Ice Worm Glacier runoff

Crevasse on Lynch Glacier

[gb]

The NWS Seattle has monthly graphs showing that Sea Tac has been above normal since the latter half of April. Nighttime temperatures have been especially so. http://www.wrh.noaa.gov/climate/temp_graphs.php?stn=KSEA&wfo=sew But it seems to me that freezing levels have been even more dramatically warm, with the majority of the summer at 13500' to 14500'. Are there any weather records that show average freezing levels for this summer as compared to normal?

[peltoms]

Since freezing levels are forecast and not measured, I am not aware of a record. The Camp Muir temperature record would be pretty good though. I will wait for more a detailed look until September ends.

[lopper]

Thank you for another year's collection of glacier data and images.

[puzzlr]

I really enjoy reading these reports-with-pictures. I don't think I could make it through the journal articles! This year I learned about "Storm Layers", which answers some questions I've had about why some layers I thought were annual were so thin!

[Jetlag]

I can see that these high nighttime temperatures nourishing my heirloom tomatoes have not been so kind to the glaciers. The last two nights I spent in MRNP were no different - incredibly warm.

[gb]

[peltoms]

The upper air soundings in Quillayute are made but how useful is this for Cascade freezing levels? If this was Cle Elum or Monroe that would be good.

[gb]

[George Winters]

Whitechuck Glacier 1986

Whitechuck Glacier 2013

On August 7th I joined a friend on his plan to re-take a photo he took in September of 1986 near the Whitechuck Glacier south of Glacier Peak. With the help of his old photo we were able to stand in the exact spot where it was taken. I made a series of photos for a pan shot and then I have used his 1986 photo to paste in the glacier as it appeared in 1986. The two photos, when set to alternate back and forth, really emphasize how much volume of glacier has disappeared there. The effect for me is much more dramatic than looking at a line drawn that represents the changing terminus. In the 2013 photo, people standing on the far edge of the fringe of snow on the glacier, show as barely discernible dots. On Glacier Peak, only the Whitechuck glacier has made such a dramatic change in recent decades. This glacier is somewhat lower and has a westerly aspect (but its top edge is on a north facing ridge), still, it is surprising to me that it has changed so much more dramatically than the other glaciers in that area.

[Jetlag]

George, good point about the Whitechuck glacier's amazing retreat. I wish I had saved my pictures from the early 70's. The Honeycomb glacier, just east of the Whitechuck, draining the other side of Kololo, is also impressively shorter but much thicker.

[peltoms]

Yes, good old Whitechuck, White River has changed about the same amount. Note the previous work on that we have done.

[peltoms]

Field Project video

[gb]

Interesting set of videos. The video of the Lower Curtis reminds me of old turn of the 19th century photographs of early explorers on the Illecillewaet (called at that time "The Great Glacier"). The glacier still remains but the rounded character of the seracs and many annual lines seem to indicate that not much is happening. I know you follow Canada, too, as I think I've seen your work on the Columbia Glacier from the Icefield. As warm as this summer has been here, in Canada it has doubtless been without precedent, with average temperatures (from Environment Canada) running probably 3 to 8 degree C above normal the entire summer. Historically, the Canadian Rockies glaciers have survived not on the basis of snowfall, particularly in winter (because winters are pretty dry), but because of cloudy, cool weather that has been the norm for all but a few weeks in the summer. I would think on the high icefields that April, May, June snowfall has been very important. I've followed trip reports from Canada and this one (there are several) from Mt. Ball near Vermillion Pass shows almost no firn remaining on the glaciers at all. http://www.clubtread.com/sforum/topic.asp?TOPIC_ID=57887 It appears obvious that many of these glaciers are not really moving anymore at all, just melting in situ. Crevasses appear to be just old cracks. Are there many glaciers that you know of in the Cascades that are no longer moving, but just thinning and melting? Or do most still exhibit some movement?

[peltoms]

Most of the glaciers larger than 0.2 square kilometers still move. Glaciers like the Colonial Glacier are exceptions that are larger and do not move. All of the glaciers we work on except Ice Worm Glacier are still moving. Cracks look much different than crevasses, I do not see alot of these.