Tag: british columbia glacier melt climate change

Falcon Glacier, British Columbia Wings Clipped by Climate Change

On By mspeltoIn British Columbia glacier retreat1 Comment

Falcon Glacier in 1985 and 2019 Landsat images indicating the 2000 m retreat.  Red arrow is 1985 terminus location, yellow arrow the 2019 terminus location. I=icefall locations joining the glacier.

Falcon Glacier in southwest British Columbia drains east from the Compton Neve into the Bishop River, which then joins the Southgate River. The Southgate River is one of three major watersheds emptying into the head of Bute Inlet. The Southgate River is known for the large runs of Chum Salmon. The area was the focus of a proposed Bute Inlet hydropower, that at present is no longer being pursued.  The region has experienced large negative mass balances 2000-2018 (Menounos et al 2018), that is driven retreat of many glaciers in the immediate area such as Bishop Glacier and Klippi Glacier.  Here we examined Landsat images from 1985 to 2019 to determine the response to climate change of Falcon Glacier.

In 1985 Falcon Glacier terminated at 980 m and was over 10 km long (red arrow).  There were two icefalls (I) feeding the glacier along with the two principal tributaries.  By 2002 the glacier had retreated 800 m, with narrow ponding in front of the terminus.  The two icefalls were still active and the medial moraine extending to the terminus had increased prominence. By 2015 the glacier had retreated another 800 m and the two icefalls are barely connected to the main glacier.  The snowline is higher in 2015 at 1850 m.  By 2019 Falcon Glacier had retreated 2000 m, losing 20% of its length since 1985.  The eastern icefall no longer rejoins the main glacier.  The western icefall is barely connected.  The snowline in early August 2019 is already at 1850 m indicating a limited accumulation area again. The high snowlines and continued expansion of bedrock areas even at 2000 m indicates the glacier will continue its rapid retreat.

Falcon Glacier in 2002 and 2015 Landsat images indicating the 2000 m retreat.  Red arrow is 1985 terminus location, yellow arrow the 2019 terminus location. I=icefall locations joining the glacier.

Map of Falcon Glacier indicating flow direction and icefalls (I). 

Klinaklini Glacier, British Columbia Retreat Generates Large Icebergs

On By mspeltoIn British Columbia glacier retreat, Canada glacier retreat

Klinaklini Glacier comparison in Landsat images from 1987 and 2017.  Red arrow 1987 terminus, yellow arrow 2017 terminus and snowline at purple dots.

Klinaklini Glacier is the largest glacier in the Coast Mountains of British Columbia between Vancouver and Prince Rupert.  The glaier drains west and south from Mt. Silverthrone.  There is significant accumulation area above 2500 m and the glacier terminates at 300 m.  GLIMS noted the area in 2004 as ~470 km2.  Glaciers in this region are retreating and losing volume, Schiefer et al (2007) noted that the rate of volume loss had doubled in  the most recent decade.  Clarke et al (2015) modeled a 70% loss in volume of all glacier in western BC by 2100. Here we examine Landsat imagery from 1987-2017, to identify changes.  In particular examining the area of large icebergs in 2015-2017 generated from a rapid calving retreat that has occurred since 2010. The glacier drains in to Knight Inlet a famous area for salmon fishing. 

I first saw this glacier in 1982 and at that time it ended on an outwash plain with a narrow lake/wide river leading from the terminus.  In 1987 the terminus was at this same location, red arrow, with no significant lake at the terminus.  The snowline in 1987 is at 1500 m.  By 1995 a lake had formed across the width of the terminus.  The lake was than 600 m long and the snowline was at 1600 m. In 2010 the glacier had retreated more than 1 km across its entire 1.3  km width.  The lake at the terminus had a surface area greater than 1.5 km2 and was largely filled with icebergs.  The snowline in 2010 is at 1500 m.  By 2013 the main proglacial lake has expanded to a length of over 2 km and remained largely filled with icebergs.  Retreat from 2010-2013 was as great as the retreat from 1995 to 2010.  The snowline in 2013 was at 1600 m.  From 2013 to 2014 there was no real change in the terminus position and the largest iceberg remained the same, pink (1).  In 2015 the snowline is at 1600 m and is at 1700 m in 2016.  In the side by side comparison of the terminus in 2015, 2016 and 2017 it is apparent that there was limited retreat from 2013, and a large calving event in 2017 generating an iceberg with an area of 0.7-0.9 square kilometers, pink (2), along with other smaller icebergs.  The lake is now 4 km long, yielding a retreat rate of 130 m/year from 1987-2017.  Nearly 50% of the retreat occurred in 2017.  In 2017 the snowline is at 1700 m as well.  The high snowlines each year are leading to mass loss, which leads to reduced flow through the ablation zone.  The thinning terminus due to higher ablation and less flux from above is then more prone to breakup.  The Klinaklini Glacier wins the prize for the largest observed iceberg produced by a glacier in Western Canada. The retreat is similar to other valley glaciers in the region Bishop Glacier, Jacobsen Glacier, Bridge Glacier and  Klippi Glacier.

Comparison of the terminus, pink dots in 2015, 2016 and 2017.  The red arrow is the 1987 terminus, yellow arrow the 2017 terminus and the largest icebe

rgs also labelled. 

 

Canadian Columbia River Basin Winter 2016-2017: A Late Rally

On By mspeltoIn Glacier Observations, Uncategorized

Guest Post by Ben Pelto, PhD Candidate, UNBC Geography, pelto@unbc.ca

As the summer ticks by and the fall glacier field season approaches, I’ve realized that I never put out a winter 2016-2017 synopsis, so, like the snowfall this year, it’s arrived late.

May 2017, Jesse Milner of the ACMG on the Nordic Glacier in front of the “meteor strike” a newly exposed rock face that spalls ice regularly. Photo by Ben Pelto.

Story of the winter

The winter began with an extremely warm November, featuring temperatures 2-5˚C above normal, with greater than average precipitation generally delivered via Pacific storm cycles. Arctic air masses moving south across BC dominated December, with a complete reversal of temperature to well below average temperatures (Figure 1), and drier conditions. By January 1st the BC River Forecast Center announced that the Columbia River Basin was at 80-88% of normal snowpack (Figure 2).

Figure 1. Maximum temperature anomaly for December 2016. Note Columbia Basin (SE BC) roughly 3˚C below normal (Pacific Climate Impacts Consortium).

Figure 2. January 1st snow survey data from the BC River Forecast Center. The Columbia River Basin is comprised of the Upper Columbia, East Kootenay, and West Kootenay Basins, which range from 80-88% of normal.

March and April brought cool and moist unstable conditions, leading to a significant increase in snowpack across southern BC, delaying the onset of the melt season by about two weeks. Snowpack measures for the basin were over 100% of normal for the first time of the winter; by May 1st, the Columbia Basin was at 115% of normal to the north and 135% in the south (Figure 3). By the first week of May, most regions had transitioned into the melt season, though at low to mid-elevations (below 1500 m) much of the snow had already melted.

Figure 3. May 1st snow survey data from the BC River Forecast Center. The Columbia River Basin is comprised of the Upper Columbia, East Kootenay, and West Kootenay Basins, which ranged from 115 to 137% of normal.

Questions of alpine snowpack conditions

A trend seen over the past few winters is minimal to no snow at lower elevations with significant snow remaining higher, and it’s a pattern expected to continue in an era of rising temperatures leading to both rain on snow, and melt events through the winter. Unfortunately, current measurements, including the network of 70 automatic snow weather stations (ASWS) across the province, are all located at or below 2000 m. This leaves the alpine largely un-sampled. Rising temperatures may well be increasing the balance gradient of winter snow accumulation; that is, there will be a greater rate of change (increase) in snowpack with elevation than previously experienced, though data for this shift is lacking.

Our glacier research program

This information gap of alpine snowpack across BC is being addressed within the context of our glacier mass balance network funded by the Columbia Basin Trust. Each year we have been studying a series of five glaciers across the Basin, which from north to south are the Zillmer Glacier (Valemount), Nordic Glacier (northern boundary of Glacier National Park), Illecillewaet Glacier (Parks Canada, Rodgers Pass, Glacier National Park), Conrad Glacier (Golden, northern boundary of Bugaboo Provincial Park), and the Kokanee Glacier (Nelson, Kokanee Glacier Provincial Park). For more background see previous posts here and here.

Our spring field season consists primarily of snow depth measurements and snow density measurements, used to determine the snow water equivalent (SWE) retained on each glacier at the winter’s end. We also conduct GPS surveys of the glacier height, which we use to account for any surface height change between field visits, and the subsequent airborne laser altimetry surveys (LiDAR)of each glacier and the surrounding area that we’re conducting every spring and fall for the five years of the project.

May 2017, Pulling the ground penetrating radar up the Kokanee Glacier to measure ice thickness. The Kokanee is 20-80 m thick, averaging around 30-40 m. Photo by Rachael Roussin.

Our LiDAR data allows us to calculate snow depth by comparing a fall LiDAR-derived digital elevation model (DEM) to our spring DEM. Off-glacier, the fall DEM represents bare earth, and on glacier, the glacier surface at the end of the melt season. The spring DEM thus captures the fall surface height plus the winter snowpack. The difference in height between the two is taken to be accumulated snow. While our manual snow depth and density surveys of the five study glaciers are incredibly valuable data, our LiDAR surveys cover roughly 10% of the Columbia Basin glacier area, a more than three-fold increase. This expanded footprint allows a better picture of alpine snowpack across the province at elevations largely un-sampled; highly important to downstream concerns such as spring flooding and  snow available for summer streamflow.

Fires and Floods

 Dramatic swings of weather patterns characterized the 2016-2017 winter, with snowpack well below average in February and early March for the province. By the end of April, snowpack across the Columbia Basin and southern half of the province had rebounded to average or record levels depending upon location with Vancouver and the lower mainland receiving significant snowfall to much fanfare. 

The late and cool spring saved the snow season, but also led to flooding across the province, particularly throughout the Okanogan and around Kelowna. As the wildfire season began in earnest, sandbags were still in place in Kelowna to protect properties against flooding from Okanogan Lake, which remained above full pool by 38 cms on July 10th. Wildfire crews had been tasked with fighting the flooding, and were removing many sandbags as lake levels began to fall before heading off to respond to escalating fires. The flooding began following a rapid warm-up combined with heavy rainfall that led to extreme avalanche risk and activity, with highway closures along the Trans-Canada and Icefields Parkway.

The record snowpack across the southern-most Columbia Basin such as around Nelson, BC, has long since disappeared, with Nelson implementing water restrictions to attempt to cut water usage by 50% in response to the rapidly diminishing snowpack which feed the town’s water supplies.

Forest fires have been raging over the province, burning an area larger than Prince Edward Island, in what is the worst fire season in BC since 1958. Forest fire impact on glaciers is largely unknown, as soot and ash from the fires may raise albedo, but smoke clouds reflect incoming solar radiation. One thing is for certain however, should the fires cloud the skies during our field season, spending 24 hours a day in fire smoke makes for a tough go.

Team members at the foot of a recent avalanche preparing to head up to the Nordic Glacier in the first week of May 2017. Photo by Alex Bevington

Outlook

With our fall field season (August 19-September 21) only a week away, it will be an interesting time to observe how our study glaciers across the Columbia Mountains fared over this roller coaster of a year. After a cold, dry start to the winter, a late rally in March and April delayed the start of the melt season and raised snowpack to well above average across the Columbia Basin. A hot, dry summer led to flooding in May, and now wildfires in June-August, which reversed snowpack levels to below-average at most elevations. Satellite images of the study glaciers show rapidly rising snow lines, as above-average snow packs are reduced to average to below-average across most glaciers, with only the Kokanee Glacier appearing set for a possible positive mass balance year.

How do you get out? Jesse Milner at the bottom of a 5.5 m deep snow pit, which we use for sampling snow density. Nordic Glacier. Photo by Alex Bevington.

The field research is funded by the Columbia Basin Trust, with BC Hydro providing funds for the LiDAR surveys, and addition research support from the Natural Sciences and Engineering Research Council of Canada and the Canada foundation for innovation. The author is a supported by a Pacific Institute for Climate Solutions Fellowship and a scholarship from the University of Northern British Columbia.

Beautiful British Columbia Land of Many Mountains & Dwindling Glaciers

On By mspeltoIn Canada glacier retreat

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British Columbia is host to many mountain ranges; Purcell, Monashee, Bugaboo, Selkirk, Cariboo, Coat Range, Kootenay, Kwadacha are just some of the diverse mountain ranges  that host glaciers and span climate zone. A shared characteristic today regardless of climate zone or mountain range is dwindling glacier size and volume.  Bolch et al (2010) found that from 1985-2005 Alberta glaciers lost 25% of their area and BC glaciers 11% of their area.  Tennant and Menounos (2012) examined changes of the Rocky Mountain glaciers including Alberta finding that between 1919 and 2006 glacier cover decreased by 590 square kilometers, 17 of 523 glaciers disappeared and 124 glaciers fragmented into multiple ice masses.  Jiskoot et al (2009) examined the behavior of glaciers of the Clemenceau and Chaba Icefield and found that from the mid 1980’s to 2001 the Clemenceau Icefield glaciers had lost 42 square kilometers, or 14% of their area. Pelto (2016) reported on specific retreat of many of these BC glaciers. Below are links to 31 detailed post examining the changes in recent decades of British Columbia glaciers in response to climate change.

In the summer glaciers in many ranges are crucial water resources for aquatic life and hydropower.   In BC 92% of electricity is generated by hydropower mainly from large projects.  BC Hydro has 31 such large projects, including several heavily fed by glaciers: Bridge River, Mica, Cheakamus, Ruskin and Stave Falls. There are also run of river hydroprojects with a new one constructed by AltaGas, the 195 MW Forrest Kerr Project on Tahltan First Nation land on the Iskut River. The Iskut River like the Stikine River is heavily glacier fed. As spring begins glaciologists will be heading out to measure glacier mass balance a critical input to understanding current and future glacier runoff, such as the Columbia Basin Trust sponsored project overseen by Brian Menounos at UNBC, and field operation direct by Ben Pelto at UNBC.


Forrest Kerr Hydro is a run of river project relying on a weir instead of a dam to divert water into the intake.
There are also numerous salmon fed streams with critical glacier input, such as the Skeena River and Rivers Inlet. Stahl and Moore (2006) identified that discharge from glacierized and nonglacierized basins in British Columbia indicates the negative August streamflow trends illustrate that the initial phase of increase runoff causing by climate warming has passed and runoff is now declining. This is similar to further south in the North Cascades of Washington (Pelto, 2015).

Shatter and Shudder Glacier
Snowcap Creek Glacier
Stave Glacier
Helm Glacier
Warren Glacier
Galaxy Glacier
Icemantle Glacier
Big Bend Glacier
Kokanee Glacier
Toby Glacier
Conrad Glacier
Vowell Glacier
Bridge Glacier
Klippi Glacier
Yoho Glacier
Des Poilus Galcier
Haworth Glaciers

Apex Glacier
Kiwa Glacier
Dismal Glacier
Cummins Glacier
Coleman Glacier
Swiftcurrent Glacier
Bromley Glacier
Sittakanay Glacier
Nass Peak Glacier
Porcupine Glacier
Great Glacier
Hoboe Glacie
Tulsequah Glacier
Melbern Glacier

Bridge Glacier Terminus Collapse, BC, 4 km retreat 1985-2016

On By mspeltoIn Canada glacier retreat1 Comment

Bridge Glacier comparison in 1985 and 2016 Landsat Images.  Red arrow is the 1985 terminus, yellow arrow the 2016 terminus and purple arrows indicate locations where tributaries have separated between the two dates. 

Bridge Glacier is an 17 km long outlet glacier of the Lillooet Icefield in British Columbia. The glacier ends in a rapidly expanding glacial lake and had an observed retreat rate of 30 m per year from 1981-2005 by Allen and Smith (2007). They examined the dendrolchronology of Holocene advances of the glacier and found up to 2005 a 3.3 kilometer advance from the primary terminal moraine band, with the most extensive advances being early in the Little Ice Age.  Chernos (2016)  indicates that the glacier in 2013 is approaching the upglacier end of the lake, which will lead to reduced retreat rates.  Here we compare Landsat imagery from 1985 to 2016 to determine response.

In 1985 the proglacial lake was 2.5 km long and 3.5 km upglacier of the terminus a major tributary joins.  The transient snow line is 2100 m. By 1993 the glacier has retreated 200-300 m and the snowline was at 2150 m.  By 2004 the terminus in a Google Earth image the terminus had retreated 1100 m since 1985.  By 2004 the tributary from the north has separated from the north side of the glacier.There are also some evident areas where the proglacial lake is visible up to 800 m upglacier of the terminus.  This suggests imminent collapse of this section of the terminus, which is afloat.  Matt Chernos researching this glacier documents this well with images.  Chernos (2016) observed that calving due to greater water depth and terminus buoyancy was key to retreat, but that most volume loss stemmed from melting.   In 2016 the terminus has retreated beyond the former junction of the Bridge Glacier and the northern tributary.  The glacier terminus is now within 500 m of a slope increase, likely marking the end of the developing lake basin. The total retreat in 31 years has been 4.1 km, this is a rate of 130 m/year, much faster than before. The 3 km retreat from 2004 to 2016 indicates a retreat of 250 m/year.  The separation of the three tributaries, purple arrows are not impacted by calving and indicate melting alone is sufficient to drive significant retreat.  The enhanced melt is also the cause of the high snowlines,, in 2016 the snowline is at 2150 m. The retreat is faster than nearby Klippi and Jacobsen Glacier, but both of those are also retreating fast.

This continued retreat and area loss will lead to glacier runoff decline in summer. This is crucial to the large Bridge River Hydro complex. This complex managed by BC Hydro can produce 490 MW of power, which is 6-8% of Province demand. Stahl et al (2008) note in their modeling study of the glacier that ,”The model results revealed that Bridge Glacier is significantly out of equilibrium with the current climate, and even when a continuation of current climate is assumed, the glacier decreases in area by 20% over the next 50 to100 years. This retreat is accompanied by a similar decreasein summer streamflow.”   Lillooet News (2016) notes that BC Hydro has commissioned research on the glacier to investigate impact on runoff tiiming. This parallels our findings on the Skykomish River in the North Cascades, Washington Pelto (2011).  The change in timing and the hydropower also impact salmon with late summer runs of chinook and fall coho runs.

Bridge Glacier comparison in 1993 Landsat Image.  Red arrow is the 1985 terminus, yellow arrow the 2016 terminus.

2005 Google Earth image of Bridge Glacier, note tributary separation from the north.

Closeup of terminus indicating exposures of proglacial lake upglacier of the terminus.Bridge Glacier Retreat Acceleration, BC, Canada

Klippi Glacier Retreat Causes Separation, British Columbia

On By mspeltoIn Canada glacier retreat1 Comment

Klippi Glacier in Landsat images of 1987 to 2016. Red arrows indicate 1987 terminus, yellow arrows 2016 terminus and purple dots the transient snowline. 

The glacier beings at 2600 m sharing a divide with Klinaklini Glacier, flowing northwest from Silverthrone Mountain and terminating at  1040 m in 1987. Klippi Glacier drains into the Machmell River, Owikeno Lake and then River Inlet on the British Columbia Coast. The Machmell River is an important spawning area in its lowest 20 km, particularly for sockeye salmon, with chinook, coho, pink and chum salmon also present  The Machmell River is accessible to anadromous fish to the cascades just downstream of junction with Pashleth Creek, where runoff from the Pashleth Glacier enters (Hillaby, 1998).  The Rivers Inlet sockeye stock is the second largest in BC and has recently received much attention because of a dramatic decline in total abundance from the 1980s.  In the 1980’s Machmell River escapement numbers averaged 20,000, dropping to 5000 in the 1990’s  (Rutherford et al 1998).  This has led to an ecosystem study by UBC and SFU  of Rivers Inlet. Rivers Inlet in the 1970’s began to experience sockeye population  decline. Harvest rates were reduced in the 1980’s and the commercial fishery closed in 1996.  In 1999 the  stock reached a record low of ~ 3600 fish, just 0.1% of historic levels (Rivers Inlet Ecosystem Study). The commercial fishery has remained closed since 1996, with  a small amount of fishing permitted by the Wuikinuxv First Nation for cultural purposes, the stock has not recovered.

Here we examine the response of this glacier to climate change from 1987-2016 using Landsat imagery. In 1987 Klippi Glacier’s two main tributaries joined 1.8 km from the terminus, red arrow in each image.  The transient snow line was at 1800 m, purple dots.   By 1995 the glacier had retreated 750 m but still had a joined terminus. The transient snowline remained close to 1850 m.  In a 2012 Google Earth image the tributaries are still connected, but barely as a drainage stream has nearly isolated them.  The lower 800 m of both glaciers illustrate limited crevassing and significant downwasting. By 2016 the tributaries had separated with a retreat of  1400 m since 1987.  The transient snowline in 2016 was at 1900-1950 m. The glaciers will continue to retreat due to high snowlines in recent years with each of the last three years being above 1950 m by the end of the melt season.  The retreat here is similar to that of other valley glaciers in the region Jacobsen Glacier and Bridge Glacier.

Map of the Klippi Glacier region reflecting the 1980’s terminus position of the glacier. Red arrows indicate 1987 terminus, yellow arrows 2016 terminus

Klippi Glacier in Landsat image from 1995. Red arrows indicate 1987 terminus, yellow arrows 2016 terminus and purple dots the transient snowline. 

2012 Google Earth image of the terminus area of Klippi Glacier. Yellow arrow indicate 2016 terminus location. 

Canadian Columbia Basin Glacier Fall 2016 Field Season

On By mspeltoIn Canada glacier retreat

Guest Post by Ben Pelto, PhD Candidate, UNBC Geography, pelto@unbc.ca

gmb

Figure 1. An illustration of the glacier mass balance sum. Mass balance is equal to the amount of snow accumulation and the amount of ice melt over time. Traditionally, this is reported as annual mass balance (how much mass a glacier gained or lost in a particular year) and is reported in meters water equivalent (mwe).

The Columbia Basin Glacier Project is studying the mass balance of several glaciers in western Canada to assess their ‘health’ over time (Figure 1) using field-based measurements and remote sensing. This work is funded by the Columbia Basin Trust and BC Hydro. During the fall season of 2016, we visited our four study glaciers in the Columbia Mountains (Figure 2). These form a transect from south to north: the Kokanee Glacier (in the Selkirk Range), Conrad Glacier (Purcell Range), Nordic Glacier (Selkirk Range), and Zillmer Glacier (Premier Range). We also visited Castle Creek Glacier and the Illecillewaet Glacier with Parks Canada. This post is an overview of the field season and some preliminary results for 2016.

 If you are interested in our main research objectives and methods, you can see the abstract from my recent talk at the American Geophysical Union conference and a video of an accompanying press conference (my piece starts at 18 minutes) with Gerard Roe (University of Washington) and Summer Rupper (University of Utah) titled: Attributing mountain glacier retreat to climate change. More information can be found in the November 29th episode of the Kootenay Co-op radio program Climate of Change (start at 34 minutes).

  areamap
Figure 2. Map of the Columbia River Basin in Canada. Our six study glaciers are marked by red stars. Other glaciers are in light blue (from the Randolph Glacier Inventory) and major rivers and lakes are in dark blue.

Our research consists of both field work and remote sensing. The fieldwork involves manually measuring the amount of snow that accumulates and ice that melts on each glacier at the start (spring) and end (fall) of each melt season (Figure 3). This gives us a mass balance measurement for individual glaciers but is very labor intensive (even if the views are great!). The remote sensing portion of the project is conducted using aerial laser altimetry (Figure 4). To conduct the laser altimetry we mount a Light Detection and Ranging (LiDAR) unit to the bottom of a fixed-wing aircraft and fly surveys of the glaciers twice each year. This creates two 3-Dimensional models of each glacier, one for the spring and one for the fall. When we subtract the spring model from the fall model, we are left with the thickness change of the glacier, and can thus derive mass change. We are still developing this method as a means of measuring more glaciers each year than could be achieved in the field.

 p1030807

Figure 3. To measure ablation (ice melt) we use ablation stakes drilled into the glacier in fall so that the top is flush with the ice surface. The following year, we visit the stakes to measure how much ablation has occurred during the summer, and then drill them in again to record the next year’s melt. In fall 2015, the top of this stake in the terminus of Nordic Glacier was flush with the ice surface, so it has lost nearly 3 meters of ice thickness (photo by Micah May). kokan

Figure 4. Kokanee Glacier elevation change map showing the difference in glacier elevation between September 2015 and September 2016. The difference can be used to calculate glacier mass loss. The glacier (black outline) flows from the bottom of the page to the top, so the terminus of the glacier lost the most mass whereas the middle reaches are net neutral and the upper reaches gained mass. Non-ice areas (e.g. rock) are white because there was no elevation change. The blue and red patches outside the glacier are changes in seasonal snow patches and fresh snow deposited in depressions after a small storm at the time of the 2016 survey.

The year of 2015 was a record for glacier melt across western North America. By contrast, 2016 resulted in slightly negative mass balance for our study glaciers. This means that on average the glaciers we studied lost far less mass in 2016 than in 2015 (and 2014, see Figure 5).

 
conrad

Figure 5. The Conrad Glacier terminus in 2014 (on the left) and 2016 (on the right). Between 2014 and 2016, the terminus of this glacier retreated by 75 m (yellow arrows) and the glacier also thinned markedly. The visibility of the rock band in the center of the image shows this thinning of the ice (red arrows). Also note the orbital crevasses (green arrow), which formed due to the collapse of ice caves along the margin. These ice caves formed in 2014 and 2015 as the surrounding exposed rock warmed (via solar heating) and melted the ice margins from below, and subsequently collapsed in 2016.

Spring arrived around four weeks earlier than normal this year, as we noted in our spring report, with the melt season commencing near the start of April instead of the start of May. At the beginning of April, the 2015-2016 winter had resulted in average snowpack in the northern half of the Columbia Basin and above-average snowpack in the southern half. However, early hot temperatures during April then led to early melt instead of a slow increase in snow throughout the rest of the spring. By mid-April, the snowpack across the entire basin had dropped to under 50% of the normal amount. One caveat here is that province-wide snow monitoring includes many measurements at around 2000 m, but very few above this elevation. Most glaciers in the Columbia Basin lie above 2000 m elevation, so our understanding of the snowpack affecting these glaciers is limited. While there are no long term records for higher elevations in the basin, our data, and discussions with local ski guides and lodge operators, suggests that the snowpack was probably around average during winter 2015-2016 until April.

Our measurements indicate that overall, the 2015-2016 winter resulted in a snowpack that was only 7% lower than the 2014-2015 winter. Why, then, was 2015 a year of substantial mass loss in the Columbia Basin but 2016 only a slightly negative year? The answer is that temperature difference has a far greater impact in this region than the amount of snow accumulation. In our region, at the elevation where glaciers are located (generally above 2000 m), the variability in snowfall year to year is far smaller than the variability in annual temperatures. Temperatures have risen over the Canadian portion of the Columbia River Basin by 1.5°C over the past century, more than double the global rate according to the Columbia Basin Trust. Due to rising temperatures, above-average snowpack is needed just to break even in a typical year. Thus, in order to have a positive mass balance year, you need above average snowfall and below average temperatures.

The summer of 2016 featured average to slightly above average temperatures (Figure 6), with a cooler-than-average July. This is in contrast to the last two years, which both featured well-above-average temperatures through the melt season. Precipitation was also about average over the basin during the summer months (Figure 7). The basin began with a roughly average alpine winter snowpack, experienced an early and hot spring, slightly warmer-than-average summer temperatures, and average precipitation. The combination of these factors led to a slightly negative mass balance overall for our glaciers in 2016: those in the north lost around 0.5 mwe and those in the south stayed around neutral or even slightly gained mass.

 2016jja_temp

Figure 6. Summer (June/July/August) mean daily maximum temperature anomaly for British Columbia in 2016. The red ellipse highlights the Columbia Basin, where temperatures were average to slightly above average (data from the Pacific Climate Impacts Consortium).

The 2016 trend was likely due, in part, to the prevailing position of the jet stream in the 2015-2016 winter. The northerly position of the jet stream, and persistent ridge over the Pacific Northwest, led to warmer winter temperatures over the southern part of the Columbia Basin but also more moisture and concentrated storm tracks (calcification: while accumulation variability resulting from winter weather patterns may have played a role in the north-south trend, the magnitude of mass change (small loss) was controlled by melt season temperatures). My favorite location to observe the jet stream in winter is from the California Region Weather Server at San Francisco State University. There have been many discussions of the jet stream behavior and its influence on winter weather in this region (here’s a simple overview from NOAA). The north-south trend was observed in 2015 as well, but in reverse, with the glaciers in the south experiencing greater mass loss.

2016jja_ppt

Figure 7. Summer (June/July/August) precipitation anomaly for BC. Red ellipse highlights the Columbia Basin. Columbia Basin precipitation was net average to slightly below average for summer 2016 (Pacific Climate Impacts Consortium).

Well-above-average snowfall and well-below-average spring, summer and fall temperatures would be needed for any of the Columbia Basin glaciers to gain substantial mass. This has happened just twice over the past 20 years, as recorded by the North Cascades Glacier Climate Program in the North Cascades of Washington, just southwest of the Columbia Basin. During the winter of 1999, Mt. Baker set the record for most snowfall ever recorded in the US at 1140 inches (or 2900 cm, yes…29 meters!), leading to average glacier mass gain of over 1 meter water equivalent (mwe). The winter of 2011 also featured above average snowpack, and in combination with a cool and cloudy summer, led to below-average melt and a positive mass gain of over 1 mwe. Unfortunately, closer to the Columbia Basin, the Peyto, Place and Helm Glaciers of British Columbia, have never reported a mass gain of 1 mwe since Geologic Survey of Canada records began for those glaciers in the 1960s and 1970s.

The take home points: 

  • In 2016, glaciers in the Columbia Basin experienced a slightly negative mass balance year. There was slight mass gain in the south (less than +0.25 mwe) and moderate mass loss in the north (around -0.5 mwe).
  • At present, an average year still results in moderate glacier mass loss in the Columbia Basin. Either above-average snowpack or below-average temperatures are needed during the melt season for a neutral mass change. A combination of both is required for the glaciers to gain mass.

 If you want to see what our fieldwork looks like in practice, see my video from the spring field season.

 

Porcupine Glacier, BC 1.2km2 Calving Event Marks Rapid Retreat

On By mspeltoIn Canada glacier retreat, glacier climate change7 Comments

porcupine iceberg comparison

Landsat images from Sept. 2015 and Sept. 2016.  Red arrow is the 1988 terminus and the yellow arrow the 2016 terminus.  I marks an icefall location and point A marks the large iceberg. 

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 square kilometer iceberg break off, leading to a retreat of 1.7 km in one year. 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 has generated better imagery to illustrate my observations. Bolch et al (2010) noted a reduction of 0.3% per year in glacier area in the Northern Coast Mountains of British Columbia from 1985 to 2005. Scheifer et al (2007) noted an annual thinning rate of 0.8 meters/year from 1985-1999. Here we examine the rapid  retreat of Porcupine Glacier and the expansion of the lake it ends in from 1988-2016 using Landsat images from 1988, 1999, 2011, 2015 and 2016. Below is a Google Earth view of the glacier with arrows indicating the flow paths of the Porcupine Glacier. The second images is a map of the region from 1980 indicates a small marginal lake at the terminus.porcupine long term compare

Landsat images from 1988 and 2016 comparing terminus locations and snowline. Red arrow is the 1985 terminus and the yellow arrow the 2016 terminus.  I marks an icefall location and point A marks the large iceberg. Purple dots indicate the snowline.

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. The yellow arrow indicates the 2016 terminus position.  By 1999 there was only a narrow tongue reaching into the wider proglacial lake formed by the juncture of two tributaries. In 2011 this tongue had collapsed. In 2015 the glacier had retreated 3.1 km from the 1988 location.  In the next 12 months Porcupine Glacier calved a 1.2 square kilometer iceberg and retreated 1.7 km, detailed view of iceberg below. The base of the icefall indicates the likely limit of this lake basin. At that point the retreat rate will decline.The number of icebergs in the lake at the terminus indicates the retreat is mainly due to calving icebergs. Glacier thinning of the glacier tongue has led to enhanced calving. The retreat of this glacier is similar to a number of other glaciers in the area Great Glacier, Chickamin Glacier, South Sawyer Glacier and Bromley Glacier. The retreat is driven by an increase in snowline/equilibrium line elevations which in 2016 is at 1700 m, similar to that on South Sawyer Glacier in 2016.porcupine 82716

August 27, 2016 Sentinel 2 image of iceberg red dots calved from front of Porcupine Glacier. 

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Canadian Toporama map of Porcupine Glacier terminus area in 1980.

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Google Earth view indicating flow of Porcupine glacier.

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1999 Landsat image above and 2011 Landsat image below indicating expansion of the lake.  Red arrows indicate the snowline.  Purple, orange and yellow arrows indicate the same location in each image.

porcupine glacier bc 2011

Canadian Columbia Basin Glacier Spring 2016 Field Season (winter 2015-2016 Assessment)

On By mspeltoIn Canada glacier retreat, glacier climate change, Glacier Observations

Guest Post by Ben Pelto, PhD Candidate, UNBC Geography, pelto@unbc.ca

During the spring season we visited our four study glaciers (Figure 1), which form a transect of the Columbia Mountains from the Kokanee Glacier in the Selkirk Range to the south, to the Conrad (Purcells) and Nordic (Selkirks) in the center, to the Zillmer of the Premier Range in the north. This post will explore the snowpack of winter 2016 across the Columbia Basin of British Columbia. For a video of the work this spring see here.

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Figure 1. Map of the Columbia watershed basin in Canada. Our four study glaciers are red stars, and other glaciers are teal, per the Randolph Glacier Inventory. Major rivers and lakes are blue.

Winter 2015-2016 Snowpack Summary: Early winter, September-December, 2015 brought a number of Pacific storms, in contrast to 2013 and 2014 which featured few storms and relatively dry conditions. By January 1st, snowpack across the province was near-normal, though a strong north-south gradient was observed, with above average snowpack in the south, average snowpack in central BC and well below average snowpack in the north (provincial snowpack was below normal Jan. 1st, 2015; BC River Forecast Centre). February was warm and wet, with daily temperatures 1 to 5˚C above normal. By the beginning of March, snowpack was below average over most of the province north of Prince George and Bella Coola and near or above average to the south.

Snow continued to accumulate in March, but primarily at higher elevations due to above average freezing level heights. The height of freezing levels determines whether precipitation falls as snow or rain at a given elevation. Figure 2 shows that median freezing level height is 600 m above sea level for February at the Conrad Glacier, yet this February featured an average freezing level of 1300 m. This means that on average, in the month of February, snow fell above 1300 m and rain below 1300 m (of course this is an average and any one storm may be different).  Most glaciers in the Columbia Mountains are located above 2000 m elevation, and in the winter of 2014-2015, freezing levels were often near or above the height of many of the peaks in the Columbia Mountains (3000 m), allowing for rain on snow events. Such events were reportedly rare in 2015-2016 winter until April/May, despite the fact that freezing level heights were record high for December-April (Figure 3).

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Figure 2. Estimated freezing level height (elevation of 0˚C) for the Conrad Glacier from June 2015-May 2016. Note that February-April 2016 were at or above the 95th percentile, meaning that there is less than a 5% chance that the freezing level heights will be that high given the data from 1948-2016 from which the median height is derived. Freezing levels are estimated from NCEP/NCAR Global Reanalysis data determined every six hours from 1948-present (North American Freezing Level Tracker).

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Figure 3. Estimated mean freezing level height (elevation of 0˚C) for December-April from 1948-present for the Conrad Glacier (North American Freezing Level Tracker). Note that 2016 is the year of record. Freezing levels are estimated from NCEP/NCAR Global Reanalysis data determined every six hours from 1948-present.

Warm temperatures experienced in February continued through March and April across the province. By April 1st, provincial snowpack was near-normal at 91% of average (Figure 4). The north-south gradient in snowpack grew, with the southern half of the province at or above average, and the northern half below average. Typically, May 1st marks the peak of snow accumulation, and the melt season ensues. In 2015, the melt season began in mid-April, 1-3 weeks early. The 2016 melt season began earlier still, coming in late March/early April, 4-6 weeks early. Figure 5 shows that for the East Creek snow pillow near the Conrad Glacier, snowpack peaked in late March at around 120% of normal. Early maximum snow depth occurred due to a combination of dry, warm conditions. Typically, small precipitation events continue to add snow to alpine environments through April, and by swapping precipitation for dry, warm conditions, the snowpack began to decline in earnest in late March/early April.

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Figure 4. British Columbia Snow Survey Map for April 1st, 2016 (BC River Forecast Centre). Note that snowpack is roughly average in the south and 50-75% of average to the north.

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Figure 5. Automated snow pillow data showing snow water equivalent (SWE, amount of water obtained if all the snow were to be melted per unit area) for East Creek, near the Conrad Glacier at 2004 m elevation. Note that peak SWE was 4-6 weeks early, but was around 120% of normal at the time, followed by rapid melting (BC River Forecast Centre).

By May 15th, provincial snowpack was 39% of normal (Figure 6), a rapid decline from near average mid-winter snowpack. The north-south gradient also largely disappeared, though the three basins doing the best were the North and South Thompson, and the Upper Columbia at 70-86% of normal. Interestingly the Upper Columbia contains three of our four study glaciers. The May 15th provincial average of 39% is a new record low (measured since 1980, BC River Forecast Centre). May 15th snowpack is more typical of mid-June, indicating that snow melt is about four weeks ahead of normal. Most rivers are past the spring freshet, and discharge has begun to recede. The early freshet will put pressure on summer low flows across the province in snow-melt dominated rivers.

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Figure 6. British Columbia Snow Survey Map for May 15th, 2016 (BC River Forecast Centre). Note that snowpack that was roughly average in the south as of April 1st is now well below average, and 50-75% of average to the north.

Field Work Overview—What we do: The primary goal of the spring field season is to determine how much snow fell over the winter on the four study glaciers. To do so, we take snow depth measurements using a heavy-duty avalanche probe. Snow depth is valuable information, but snow water equivalent (SWE; if you melted the snow in a given location, this would be the depth of water left behind per unit area) is the key to understanding how much water the snow contains. As you can imagine, a meter of powdery snow may contain only 10 cm of water, whereas a meter of wet snow may contain 30 cm of water. To measure density, we either take a snow core (think a tube of snow…like an ice core, except snow instead) and cut samples to weigh, or we dig a snow pit and then take samples from a wall in the snow pit. By combining measurements of density and depth, we are able to calculate SWE over the entire glacier. A typical end of winter SWE for a Columbia Basin glacier would be around 2 meters water equivalent, which would be roughly 4.5 meters of snow. By knowing how much snow covers the glacier, we know how much mass the glacier gained during the winter. At the end of the summer, we visit the glaciers again, and we measure how much melt occurred. By combining the winter accumulation of snow, and summer melt of snow and ice, we can determine how much the glacier gained or lost during the year. Figure 7 is an illustration of the product of depth and density measurements, and displays the relationship of elevation and accumulation over the Conrad Glacier. To see what we do watch: https://www.youtube.com/watch?v=wWYJdQnRq5k

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Figure 7. Winter balance gradient for the Conrad Glacier in millimeters water equivalent per meter of elevation. Snow depth increases with elevation linearly, except in topographically complex areas, and nearest the top of the glacier (3200 m). Most of the glacier area is between 2000-3000 m.

We also are flying LiDAR surveys of our study glaciers. LiDAR is a laser sensor mounted on the bottom of an aircraft. The LiDAR unit essentially shoots rapid laser pulses, each pulse hits the surface and returns to the sensor. The time it takes for the signal to travel to the surface and back tells us the distance from the plane to the ground. With this data, we can make a detailed 3-D map of the glacier surface. This map is accurate to 10-25 cm in the vertical, and 50 cm laterally. By collecting this data biannually (spring and fall) we can determine how much snow fell, or melt occurred by subtracting subsequent 3-D maps from one another (e.g. by subtracting a September map from an April map of the same year, we can determine how much melt happened between the two flights). This data offers the ability to be able to cover far larger areas than is feasible for fieldwork.

By comparing our field data with the LiDAR data, we can determine whether the LiDAR is capturing the reality on the ground, and if the field data is able to represent spatial variability in snow depth. Our LiDAR flights occur over a day or two, whereas our field data are collected over a month. In order to directly compare both, we conduct a GPS survey of the glacier surface along the center of the glacier. We then compare the difference in elevation between the survey and the LiDAR and thus can account for any melt or accumulation that occurred in the intervening days or weeks.

This spring we also collected data using a Ground Penetrating Radar (GPR) which transmits high-frequency radio waves into the ice. When the radio waves encounter a buried object or a boundary between materials, then it is reflected back to the surface where a receiving antenna records the signal. In our case, the bedrock surface below the ice is the surface/boundary we are looking for. Once we pick out the bedrock surface from the data, then the signal and travel time are used to then determine the ice thickness (Figure 8). Ice thickness is important for determining how long a glacier will survive as well as putting current rates of ice loss in perspective. We still have a lot of data to collect and process, but it seems that smaller glaciers like the Nordic and Zillmer (~5 km2) are 50-90 m thick in general, larger glaciers like the Conrad (16 km2) average 100-200 m thick.

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Figure 8. Ground Penetrating Radar data from the Conrad Glacier. The blue line marks the bedrock surface and the red line marks the airwave, which defines the glacier surface. Between the lines is glacier ice. The longer the signal travel time, the deeper the ice. For this line, the deepest point is 220 m ice depth, and the shallowest 115 m.

Field Season Stats:

  • Snow Depth Measurements: 161 discrete locations, 600+ individual measurements
  • Snow Pits and Cores (Density): 15
    • The combination of snow depth and density allow for calculation of SWE
  • Ground Penetrating Radar (GPR) Distance (Ice thickness, Figure 3): Roughly 75 km
    • GPR data allows for the calculation of ice thickness and ice volume
  • Distance Skied: 200+ km
  • Field Team Members: 8; UNBC, CBT, UBC, ACMG.
  • Glaciers with both field and LiDAR data: 4/4
  • GPS Surveys (to corroborate field/LiDAR data comparison): 4
  • Days on a Glacier: 18

Season Summary: Our data indicate that winter mass balance featured a north-south trend, with the Kokanee Glacier in the south equaling last year’s mass balance, the central region was 85% of 2015 (Conrad and Nordic), and the Zillmer in the north was around 80%. The 4-6 week head start on melt season led to higher snow density in 2016 than observed in 2015. This summer melt season will determine whether the record/near record negative mass balance seen across the region in 2015 will be rivaled or exceeded in 2016. The hot, early spring has primed the region to again break records.

Kiwa Glacier Retreat, British Columbia 1986-2015

On By mspeltoIn Canada glacier retreat, climate change glacier retreat1 Comment

compare kiwa

Kiwa Glacier retreat from 1986 to 2015 in Landsat images.  Red arrow is 1986 terminus and yellow arrow 2015 terminus location. Purple arrow indicates upglacier thinning where more bedrock is exposed.  Purple dots indicate the transient snowline

Kiwa Glacier is the longest glacier, at 9 km, in the Cariboo Mountains of  British Columbia.  The glacier drains northwest from Mount Sir Wilfred Laurier and is near the headwaters of the Fraser River, where it terminates in an expanding lake at 1465 m. Here we examine glacier change from 1986 to 2015. In 1986 the glacier terminated in the 700-800 m long proglacial lake.  The glacier has two significant icefalls above the terminus at 2300 m and 1800 m.   The lower icefall generating a series of ogives that are generated annually due to seasonal velocity fluctuations.  The ogives indicate the glacier velocity below this icefall.  There are 20 ogives in the span of approximately 1 km indicating a velocity of 50 m/year.  In 2015 the glacier still terminates in the proglacial lake that is now 1400-1500 m long indicating a retreat of 700 m in the thirty years from 1986-2015.  The lower 300 m of the glacier is nearly flat suggesting the lake will extend at least that far, note 2010 image from Reiner Thoni, Canadian Mountaineer.  This is also the extent that will be lost relatively quickly via iceberg calving and continued surface melt.  Above this point flow remains vigorous and retreat could diminish. Upglacier thinning has expanded bedrock areas even separating sections of the glacier, purple arrows. The transient snowline in mid-August in the Landsat images is at 2550 m. Driving through the area last week, the snowline is at 1000 m, quite high for mid-March.

Beedle et al (2015) note that glaciers in the Cariboo Mountains were close to equilibrium from 1952 to 1985 : 9 glaciers advanced, 12 receded, and 11 did not change. After 1985 they noted that all glacier retreated in the Cariboo Mountains. The response time of the glaciers to climate change is the main cause for the differing response of individual glaciers in the region as has been noted in other Pacific Northwest regions (Pelto and Hedlund, 2001 & Tennant et al, 2012).  Response times are faster for glaciers with steeper slopes, higher velocity/length ratios and a higher ratio of accumulation-ablation/ ice thickness.  The decline of glaciers, warm weather and reduced snowpack combined in 2015 to place a stress of Fraser River salmon due to lower discharge and higher temperature.  This could be an issue in 2016 as well.

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Kiwa Glacier in 2004 Google Earth image

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2010 Image from Reiner Thoni.  Well defined trimlines above the lake.  Note flat lower section of the glacier. 

Yoho Glacier, British Columbia Accumulation Zone Woes

On By mspeltoIn Canada glacier retreat, climate change glacier retreat

yoho glacier melt

Yoho Glacier in 2005 no accumulation zone in sight.

Yoho Glacier is the largest southern outflow draining the south from the Wapta Icefield in the Kootenay region of British Columbia. It flows 6.5 km from the 3125 m to a terminus at 2200 m. The glacier terminus reach is thin, gently sloping  and uncrevassed poised for continued retreat. An exploration of Mount Balfour in 1898 a party led by Professor Jean Habel with the packer Ralph Edwards as a guide were the first to visit and describe Yoho Glacier. There descriptions of the magnificent Takakkaw Falls down river of the glacier quickly led to it becoming a frequent destination of visitors. The glacier was also accessible. Retreat up a steep slope at 2000 m made actually visiting the glacier difficult in the middle of the 20th century.  The glacier has retreated 2.1 km in the last century leaving a vast area of bare terrain, dotted by several small new alpine lakes. Here we examine changes in the glacier from 1986 to 2015 with Landsat imagery.

yoho map final
CanadianTopographic map

In 1986 the glacier terminated in a broad 500 m wide glacier terminus at 2150 m, red arrow, the glacier tongue remained wide up to the yellow arrow, 800 m. A tributary connected to the glacier at the purple arrow, and the glacier snowline, orange dots was at 2550 m. In 1998 the terminus had not retreated significantly, but had narrowed noticably. The tributary at the purple arrow was no longer connected and the snowline was at 2750 m, leaving little of the glacier snowcovered, which equates to a significant mass loss. In 2013 the snowline again was high at 2700 m. In 2015 the glacier terminus has retreated 300 m since 1986 and is only 250 m wide. The width at the yellow arrow is 450 m. The width reduction is an indicator of how much the glacier has thinned. The snowline is at 2800 m in this mid-August image, clinging only to the high slopes of Mount Collie, and would still rise for several more weeks in the summer. The nearby Peyto Glacier has an annual mass balance record indicating a thinning of 25 m during this period (Kerhl et al, 2014).  A glacier typically needs more than 50% of its area to be in the accumulation zone at the end of the summer to be in equilibrium.  In recent years when the snowline exceeds 2700 m less than 10% of the Yoho Glacier is in the accumulation zone. If the snowline is as high as it has been recently on Yoho Glacier, that indicates the lack of a significant accumulation zone and it cannot survive even current climate.  However, in both cases the Peyto and Yoho Glacier are rapidly losing volume, but remain substantial in size and are not on the verge of disappearing in the next few decades. The retreat is similar to that of Des Poilus Glacier shown in the lower left of the Landsat images here.

yoho glacier 1986
1986 Landsat Image

yoho glacier 1998
1998 Landsat Image

yoho glacier 2013
2013 Landsat image
yoho glacier 2015
2015 Landsat image

Big Bend Glacier, British Columbia Transitions to Alpine lake

On By mspeltoIn Canada glacier retreat, climate change glacier retreat, glacier climate change, Glacier Observations

“Big Bend” Glacier is an unnamed glacier west of Big Bend Peak north of Harrison Lake in Southwest British Columbia.  In 1985 the glacier was 2.6 km long filling a low valley with a surface elevation of 1600-1800 m elevation, the topographic map indicates this basic size. Here we utilize Landsat imagery to identify the changes in the glacier from 1985-2014 due to climate change. In essence the glaciated basin is transitioning to an alpine lake basin, quickly.

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Topographic map of the Big Bend Glacier area.

In 1985 the glacier extends to the big bend in the valley marking its eastern end, red arrow.  the yellow arrow indicates an area near 1800 m where the glacier extends across the valley.  In 1992 there has been little retreat but evident thinning is leading to lake formation at the terminus and narrowing of the glacier at the red arrow. In 2002 thinning is leading to expansion of a proglacial lake both west and south of the red arrow.  The terminus retreat has still been limited, thinning is evident at the yellow arrow.  

In 2013 a new alpine lake that is approximately 1 km long has formed, as the terminus area of the glacier has collapsed. In 2014 an area of bedrock and a small lake has developed at the yellow arrow.  There is no retained snowpack below the yellow arrow in 2013, and no retained snowpack in at all in 2014.  This will likely be the case in 2015 as well.  This glacier has a lower top elevation than most in the region and will be more impacted by the warm winter conditions and high snowline of 2015. The retreat from 1985 to 2014 has been 1.1 km. This is 40% of the entire glacier length gone in 30 years. The lake itself has a deep blue color suggesting limited glacier sediment input, further indicating a lack of motion of the glacier currently or in the near past.

The glacier retreat has been more extensive than Stave Glacier or Snowcap Glacier to its east.  Koch et al,(2009) observed a widespread retreat and glacier area loss in Garibaldi Provincial Park just to the west, with 20% area loss from 1988-2005. Place Glacier is a short distance north of Big Bend Glacier has its mass balance has lost an average of 25 m of water equivalent (28 m ice) thickness since 1984, see bottom chart. This has been higher but similar in trend to other glaciers in the region.  Big Bend will disappear soon just as we obsserved already happened at Milk Lake Glacier, North Cascades, Washington.

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1985 Landsat Image

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1992 Landsat Image

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2002 Landsat Image

bigbendpeak 2013
2013 Landsat Image

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2014 Landsat Image

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North American cumulative glacier mass balance graph