Southwest Brazeau Icefield Retreat, Alberta

On January 31, 2015January 31, 2015 By mspeltoIn alberta glacier retreat, Canada glacier retreat, glacier climate change, Glacier Observations

The Brazeau Icefield straddles high peaks southeast of Jasper, Alberta. The northern outlet glaciers drain into Maligne Lake and the southern outlet glaciers drain in to Brazeau Lake and the Brazeau River. The Brazeau River flows into Brazeau Reservoir a 355 MW hydropower facility, before joining the Saskatchewan River. An inventory of glaciers in the Canadian Rockies indicate area loss of 15% from 1985 to 2005 (Bolch et al, 2010). The more famous Columbia Icefield to the west has lost 23 % of its area from 1919-2009 with ice loss at a minimum during the 1970’s (Tennant and Menounos, 2013). Here we examine an unnamed outlet glacier at the southwest corner of the Brazeau Icefield from 1995 to 2014 using Landsat imagery.

In 1995 the glacier terminated at the red arrow and was 1900 m long, orange dots mark the upper boundary. The glacier had limited retained snowpack in 1995. The poor clarity is do to forest fire smoke in the region. In 1998 the proglacial lake where the glacier terminates is much clearer, snowpack is again limited, but more extensive than in 1995. In 2002 retreat is evident as the lake is expanding as the glacier retreats. The glacier still ends in the lake and still has limited snowcover. In 2013 the glacier has retreated completely from the lake and snowcover is again limited. The lack of snowcover is persistent in the satellite images which are typically not from the end of the melt season, hence even more snowcover will be lost. Lack of a significant persistent snowcover area indicates a glacier that will not survive (Pelto, 2010). In 2014 the area experienced considerable forest fires, which leads to poor image clarity. The glacier terminus is now significantly separated from the lake and terminates at the yellow arrow. The distance from the yellow to the red arrow represents a 350-400 m retreat in 20 years. The glacier has lost 20% of its length in this period. This retreat is similar to that of Fraser Glacier and more significant given the small size of the glacier than for Saskcatchewan Glacier

1995 Landsat image

1998 Landsat image

2002 Landsat image

2013 Landsat image

2014 Landsat image

Crevasse Reduction and Retreat of Salisbury Snowfield-Almer Glacier, New Zealand

On January 27, 2015January 27, 2015 By mspeltoIn Glacier Observations1 Comment

Almer Glacier is fed by the Salisbury Snowfield which also has its own terminus, and both are former tributaries to the Franz Josef Glacier. In 2007 the Almer Glacier almost reconnected with Franz Josef Glacier. The glaciers of the southern Alps have some of the highest recorded accumulation rates in their upper sections and highest ablation in the lower reaches. Anderson et al (2006), note accumulation rates exceeding 6 m on Franz Josef Glacier. This combined with the steep slopes lead to higher velocity and extensive crevassing on even smaller alpine glaciers. Purdie et al (2014) examined modern and historic length change for Franz Josef and noted a ~ 3 km loss in length since the 1800s, with the greatest retreat from 1934 and 1983, despite two periods of advance in that 50 year period. The retreat particularly since 1983 has been punctuated by advances 1983–1999 (1420 m) and 2004–2008 (280 m), with the current retreat up to 2014 being the fastest rate of retreat during the period of record. (Purdie et al , 2014). The annual end of summer snowline surveys by NIWA monitors the Salisbury Snowfield, the snowline was 140 m or more above the equilibrium altitude in 4 of the last six years and 20-30 m below the equilibrium line altitude in the other two. The net result is significant mass loss in the last six years driven by exceptional melt, driving the retreat.

Topographic Map of Salisbury Snowfield-Almer Glacier area

Here we examine changes particularly in crevassing as well as retreat of Salisbury Snowfield and Almer Glacier from 2000-2015. In the Google Earth images from 2007 and 2013 the green arrows indicate crevassed areas and the red arrows the terminus of the Almer Glacier above and Salisbury Snowfield below. The decrease in the amount of crevassing is evident at each location. This indicates not just a reduction in velocity, but in glacier thickness that is driving flow. The thinning is evident with the emergence of a bedrock knob at the pink arrow in 2013 that had been covered by crevassed ice in 2007. The red arrow indicates the terminus where the main Almer Glacier is within 75 m of the Franz Josef Glacier. By 2013 the terminus is much dirtier and is 200 m from Franz Josef Glacier. The icefall comparison image from 2007 and 2013 indicates the reduction in width and number of open crevasses, probably in depth too. This is something Jill Pelto (UMaine) has been measuring crevasses in the field on Easton Glacier in the North Cascades over the last few years to see how crevasses are changing as a glacier thins and slows (image below).

In 2014 New Zealand had a warm year and snowlines are high for early summer in January 2015 which will continue the retreat. The Landsat image from January, 2015 suggests further retreat has occurred since 2013, but given the dirty terminus, it is to hard to determine a specific amount. The retreat here follows the pattern of glaciers across the Southern Alps of New Zealand- Lyell Glacier and Tasman Glacier

2007 Google Earth image

2013 Google Earth Image.

2007-2013 icefall closeup

2015 Crevasse Assessment, Jill Pelto, North Cascades

2000 Landsat image

2015 Landsat image

Lys Glacier Rapid Retreat, Italy

On January 23, 2015January 23, 2015 By mspeltoIn climate change glacier retreat, Glacier Observations

Lys Glacier drains south from Lyskamm in the Monta Rosa Group of Italy. This glacier has a long history of observations that have indicated two short term advances in the 20th century 1912-21 and 1973-85 amidst a broader retreat. The net change for the 1915-2004 interval was a 600 meter retreat (Smiraglia et al, 2006). They also noted a 10% area extent loss from 1975-2003, and since the glacier was advancing up to 1985 this change occurred more rapidly. The Italian Glacier Commission report on terminus change of this glacier annually in the two latest reports Lys Glacier retreated 10 m in 2012 and 20 m in 2011. The total reported retreat from 2005-2012 was 186 m, more than 20 m per year. Here we examine Landsat images from 1990 to 2014.

Google Earth Image

In 1990 two branches of the glacier merged in the valley bottom and extended to the red arrow marking the terminus of the glacier at that time. The yellow arrow indicates the 2014 terminus position, and the yellow A indicates a prominent bedrock knob that a branch of the glacier encircles, pink arrows. By 2013 the glacier in the main valley have separated, there are a few small lakes forming amidst the decaying stagnant ice tongue between the yellow and red arrow. The bedrock knob at Point A has greatly expanded. In 2014 none of the termini reach the floor of the main valley. As the stagnant ice melts, the lake area is expanding indicating that a new alpine lake will likely form. The retreat from 1990-2014 is 1300 meters. A closeup in 2009 from Google Earth indicates the two tongues with bedrock below separating them from the main valley floor, red arrows. There is still some relict ice below on the valley floor detached from the active glacier, blue arrows, that has small lake developing amid the stagnant ice. There is substantial crevassing above both actual termini, but not immediately. The retreat should slow now that the glacier has retreated onto steeper slopes, having lost the low elevation low slope valley tongue.
The retreat of this glacier is similar to that of nearby Verra Grande Glacier.
1990 landsat image

2013 Landsat image

2014 Landsat Image

Google Earth Image

Verra Grande Glacier Retreat, Italy

On January 20, 2015January 20, 2015 By mspeltoIn Glacier Observations1 Comment

Verra Grande flows south from Breithorn, in the Monta Rosa group of Italy. The glacier is 3.5 km long extending from 4000-2700 m. Carnielli (2005) noted that this glacier retreated 816 meters from 1914 to 2001. There were two period of advance 1914-1921 and 1971-1985. Retreat was most rapid from 1934-1956 and 1991-2002 (Carnielli, 2005). Here we examine the change in this glacier from 1990 to 2014 using Landsat imagery.

Google Earth Image
In 1990 the glacier terminated at the pink arrow, which is at the same location in each image. At the yellow arrow which is in an icefall in the upper ablation zone, there is complete glacier cover. The red arrow is at the 2014 terminus location in each image. By 2013 at the yellow arrow an area of bedrock has been exposed as the glacier has thinned during a period of retreat. In 2014 the glacier has retreated to the red arrow a distance of 850-900 meters from the 1990 terminus location, pink arrow. The snowline is high at 3500 m above the new bedrock area at the yellow arrow. A close up of the terminus from Google Earth in 2009 indicates the Little Ice Age moraines, blue arrows and the debris covered nature of the terminus, red dots. The retreat is similar to Sabbione Glacier and Lobbia Glacier. The Italian Glacier Commission conducts an annual terminus survey, with the most recent completed survey results posted from 2012. In 2012 there were 124 glaciers retreating, 3 advancing and 5 changed by less than two meters. This ubiquitous retreat is leading to the separation of some glaciers, development of new lakes and loss of others in the Italian Alps.

1990 Landsat image

2013 Landsat image

2014 Landsat image

Google earth terminus view 2009

Stephenson Glacier Retreat and Lagoon Development, Heard Island

On January 16, 2015January 18, 2015 By mspeltoIn afghanistan climate change, climate change glacier retreat, heard island glacier retreat, stephenson glacier retreat, stephenson lagoon glacier retreat5 Comments

The Australian Antarctic Division manages Heard Island Island and has undertaken a project documenting changes in the environment on the island. One aspect noted has been the change in glaciers. The Allison, Brown and Stephenson Glacier have all retreated substantially since 1947 when the first good maps of their terminus are available. Fourteen Men by Arthur Scholes (1952) documents a year spent by fourteen men of the Australian National Antarctic Research Expedition that documented the particularly stormy, inclement weather of the region. Their visit to the glacier noted that they could not skirt past the glacier along the coast. After crossing Stephenson Glacier they visited an old seal camp and counted 16,000 seals in the area. It is a rich area for wildlife, that should benefit from the lagoon formation overall. Thost and Truffer (2008) noted a 29% reduction in area of the Brown Glacier from 1947-2003. They also observed that the volcano Big Ben that the glaciers all drain from has shown no sign of changing geothermal output to cause the melting and that a 1 C warming has occurred over the same time period.

Hear Island Map from the Australian Antarctic Division

Stephenson Glacier extends 8-9 km down the eastern side of Big Ben. In 1947 it spread out into a piedmont lobe that was 3 km wide and extended to the ocean in two separate lobes around Elephant Spit. A picture from the Australian Antarctic Division taken in 1947 shows the glacier reaching the ocean and then in 2004 from the same location. Kiernan and McConnell (2002) identified an order of magnitude increase in the rate of ice loss from Stephenson Glacier after 1987. Retreat from the late 19th century to 1955 had been limited. As Kiernan and McConnell observed retreat began that by 1971 the glacier had retreated 1 km from the south coast and several hundred meters from the northern side of the spit. This retreat by 1980 caused the formation of Stephenson Lagoon and by 1987 Doppler Lagoon had formed as well. After 2000 the two lagoons have joined. The first image below shows the terminus locations over the last 60 years from the Australian Antarctic Division 1947-2008.

Here we examine a series of Landsat images from 2001 to 2013 to update the response of this glacier.
In 2001 the glacier has two separate termini, pink arrows,in two different lagoons, Doppler to the south and Stephenson to the east. There are numerous icebergs in Doppler lagoon but none in Stephenson Lagoon, indicating the retreat is underway. In 2008 the two lagoons are well joined, icebergs are even more numerous obscuring in this view the true location of the terminus, orange arrows. By 2010 the glacier has retreated from the main basin of the lagoon, and is at red arrow, and the lagoon is free of ice for the first time in several hundred if not several millenium. In 2013 the glacier has retreated into a narrower valley that feeds into Stephenson Lagoon. The northern arm of the glacier experienced a 1.7 km retreat from 2001 to 2013 and the southern arm as 3.4 km retreat. The period of rapid retreat due to calving of icebergs into the lagoon is over and the retreat rate will now be slower. There is still rapid glacier flow toward the terminus as indicated by extensive crevassing. The overall glacier slope is steep and accumulation rates high, which would also generate rapid glacier flow.

The AAD has a number of images in their gallery of Heard Island glaciers including Stephenson Glacier. The climate station at Atlas Cove indicates a 1 C temperature rise in the last 60 years. The AAD will also certainly be looking at how this new lagoon impacts the local seal and penguin communities. The map above indicates the importance of Stephenson Lagoon for wildlife, king penguins and cormorants are noted by AAD. The retreat of this glacier follows the pattern of glacier retreat at other glaciers on islands in the circum-Antarctic region Cook Ice Cap, Kerguelen Island , Purvis Glacier, South Georgia and Neumayer Galcier, South Georgia.

Map of retreat from superimposed on Google Earth image.

2001 Landsat image

2008 Landsat image

2010 Landsat image

2013 Landsat image

Spørteggbreen Separation and Retreat, Norway

On January 12, 2015January 12, 2015 By mspeltoIn Glacier Observations, Norway glacier retreat1 Comment

Spørteggbreen is a small ice cap just east of Jostdalsbreen, Norway’s largest ice cap. The Norway Glacier atlas chronicles the area of the 10 glaciers that comprise the ice cap at 23.8 square kilometers in 2006 (Andreassen and Winsvold, 2012). The Norwegian Water Resources and Energy Directorate (NVE) has an excellent glacier monitoring program that monitors 10 glaciers that drain Jostedalsbreen from 2008-2013 the net change was retreat on all 10. This is exemplified by Tunsbergdalsbreen. In 2014, 33 of 38 glaciers observed in Norway retreated and 5 did not change. Laumann and Nesje (2014) examined Spørteggbreen during the Holocene. They noted the glacier disappeared from 7300 years before present and reformed approximately 5400 years before present. Their model simulates minor changes from 2011 to 2050. Here we focus on changes to the southwest side of this ice cap using Landsat imagery from 1988-2014 and implications for the near future.

Norway Glacier atlas image looking southwest toward Jostdalsbreen. The foreground is the main Sporteggbreen, the new lake is in midground and then the separated southwest extension. There is no retained snowcover evident on the southwest extension and it is thin.

In 1988 at the southwest side of Spørteggbreen the main ice cap joins the southwest extension of the ice cap in a small lake at the red arrow. At the purple and yellow arrow are small peripheral proglacial lakes. The green arrow indicates a narrow section in the southwest extension. In August 1998 there is substantially more snow and lake ice, which makes identification of change difficult. In 2010 the southwest extension is well separated by a lake from the main ice cap, red arrow. This lake is m across, with the glaciers reaching the shore at both ends. The lakes at the purple and yellow arrow have also expanded. The width of the narrow section of the southwest extension has narrowed from 600 m to 300 m. In 2014 the main Spørteggbreen Ice Cap no longer reaches the eastern shore of the lake, red arrow. The lake is 750 m across. The lake at the purple arrow is now equivalent to the glacier that ends in the lake and is m long. The width of the glacier at the narrow section is down to 200 m. The most noteworthy item is that in this mid-September image the ice cap has 25% of its area still covered in snowpack, note the areas marked with pink letter A. The other areas are either firn from previous years or bare glacier ice. By the end of the melt season at the end of the month this will likely be closer to 20% . Remember a glacier typically needs 55-65 % snowcover to be have an equilibrium balance. This will lead to a large negative balance and thinning right to the top of the ice cap. This was the case in 2013 as well. Hence, the Spørteggbreen Ice Cap is currently experiencing significant volume and area losses. The retreat is not as large in terms of distance as on nearby Tunsbergdalsbreen.

1988 Landsat image.

1998 Landsat image

2010 Landsat image

2014 Landsat image

Anderson Glacier, Olympic Mountains, Washington Disappears

On January 9, 2015January 9, 2015 By mspeltoIn glacier climate change, Glacier Observations

Anderson Glacier was the headwaters of the Quinault River in the Olympic Mountains of Washington. A century ago the glacier was 2 km long, and a half kilometer wide. Retreat of this glacier in the first half of the 20th century exposed a new alpine lake as the glacier retreated 1 kilometer. From 1950-1980 the glacier diminished slowly. From 1959 to 1990 the glacier thinned and retreated from the shore of the lake trapped behind the Little Ice Age moraine. The 1959 picture below was donated to me by Austin Post. Since 1990 the glacier has begun to shrink rapidly. The Google Earth image from 1990, indicates Anderson Glacier has retreated 200 m from the 1959 terminus position near the lake shore, green arrow to the 1990 position, pink arrow. The red arrow indicates a future location of a bedrock outcrop.
1959 Austin Post image

1990 Google Earth image

Investigating this glacier in 1992 we measured its area at 0.38 square kilometers, down from 1.15 square kilometers a century before. Ten years later the glacier had diminished to 0.28 square kilometers, but had thinned even more, leaving it poised for a spectacular change, over the next five years. Large outcrops of rock appeared beginning in 2003 and further exposed in 2005 and 2007 in the middle of the glacier. Note the outcrops in the 2007 image from Kathy Chrestensen. The 2009 Google Earth image indicates the 1990 terminus position, pink arrow, and the fact that there is no longer a ribbon of snow that is even 50 m wide. The snow patches have insufficient size or thickness to be classified as a glacier. The largest outcrop at the red arrow had been beneath the ice in 1990, giving a scale to the thinning. The glacier at this point no longer exists. In 2014 an Eric Hovden image indicates some seasonal snow in the basin, but the thin ribbon of snow has numerous holes in it as well, indicating the thin nature of the remaining snow patches, with a month left in the 2014 melt season.

Kathy Chrestensen Image

2009 Google Earth Image

2014 Eric Hovden image.

This glacier had become a series of small disconnected relict glacier ice patches in 2005 and by 2009 had disappeared. It is not the only glacier that is disappearing, which has led to a visual model for forecasting glacier survival (Pelto, 2010). The key is observed retreat of the margin of the upper portion of the glacier and emerging rock outcrops in the upper part of the glacier where snow should accumulate and be retained through the melt season. If a glacier does not have a significant persistent accumulation zone it cannot survive. Anderson Glacier was not the only glacier feeding the Quinault River, all the others are retreating as well. The result of this glacier retreat is reduced late summer and early fall streamflow, impacting salmon runs at that time of the year. This is primarily the fall Coho, Chum and Chinook salmon and Steelhead summer run. During the spring and early summer runoff increases as snowmelt still occurs, but is not retained in the glacier system.To get a sense of the special nature of this area Out of the Mist is an excellent start

Nizina Glacier Retreat, Lake Formation, Alaska

On January 4, 2015January 4, 2015 By mspeltoIn glacier climate change, Glacier Observations

If you have heard of Nizina Glacier in the Wrangell Mountains of Alaska it is probably because you have contemplated a float trip down the Nizina River from Nizina Lake. In 1990 there was no lake, since 2000 the lake has provided a good location for float planes to land. In 2014 the lake has reached a new maximum in size and minimum in icebergs on its surface. Here we examine Landsat imagery form 1990-2014 to identify changes in the Nizina Glacier. The main tributary of the Nizina Glacier is Regal Glacier indicated by the dark blue flow arrows. The light blue flow arrows are from the Rohn Glacier tributary that no longer reaches the terminus area.

Google Earth image

In each image the yellow arrow marks the 1990 terminus, red arrow the 2014 terminus location and pink arrows the summer snowline. In 1990 the glacier had narrow sections of fringing lake evident, though the glacier reached the southern shore of the developing lake at yellow arrow. By 1995 the lake had developed to a width of 100-300 m fringing the shoreline around the terminus of Nizina Glacier. In 1999 the main lake has developed and is 1.6 km long and 1.3 km wide though it is still largely filled with icebergs. In 2013 there are a few icebergs left in the lake. In August, 2014 the lake is free of icebergs for the first time, which does mean more will not form. The lake is 1.4 km wide and 2.3 km long. The glacier has retreated 2.1 km from 1990 to 2014, a rate of 150 m per year, red arrow marks 2014 terminus. A close up view of the terminus in Google Earth from 2012 indicates numerous icebergs but also substantial rifts, green arrows, that will lead to further iceberg production and retreat. The snowline in this late July or early August images is typically at 1800-1900 m, pink arrow, with a month still left in the melt season. The retreat of this glacier is similar to that of glaciers in the Talkeetna Range to the west South Sheep Glacier and Sovereign Glacier and Valdez Glacier to the south.