West Speel Glacier Retreat and Lake Formation, Southeast Alaska

On June 30, 2014July 9, 2014 By mspeltoIn Glacier Observations2 Comments

West Speel Glacier is an unnamed glacier that drains the same icefield as the Wright and Speel Glacier 45 km southeast of Juneau, Alaska. Here we examine the changes in this glacier from 1984-2013 using Landsat imagery.
Google Earth image

In 1984 the glacier ended on an outwash plain at the head of a branch of Speel River. The red arrow indicates the 1984 terminus for each image, the purple arrow the 2013 terminus and the yellow arrows tributary glaciers. In 1984 all three tributary glaciers fed West Speel Glacier and the glacier has no proglacial lake at the terminus. The eastern tributary pink arrow has some retained snowpack with three weeks left in the melt season. Each tributary indicated by yellow arrow is still contributing to the glacier. In 1997 a lake basin is beginning to develop, though it is still largely filled by ice. The eastern tributary pink arrow, has lost all of its snowpack. In 1999 the proglacial lake has formed and has length of 1 km, the lake has expanded south and north of the 1984 terminus position, and does not entirely represent glacier retreat. The noted tributaries are still all connected to the main glacier. In 2013 the glacier has retreated 1200 m from the 1984 position and the lake is still expanding. The yellow arrows indicate that none of the three tributaries are still connected to the main glacier. The glacier in a sense is losing its income flow from these subsidiaries. The eastern tributary has retained some snowcover with six weeks left in the melt season in 2013, but this is mostly gone a month later. The melt season is off to a quick start in 2014, which promises to be a poor year for this glacier. The retreat of this glacier is the same story as seen at nearby Speel, Gilkey and Norris Glacier.
1984 Landsat image

1997 Landsat image

1999 Landsat image

2013 Landsat image

Sept. 2013 Satellite image

Long Peak Glacier, Southeast Alaska

On June 26, 2014June 26, 2014 By mspeltoIn Glacier Observations

“Long Peak” Glacier is an unnamed glacier southeast of Juneau, Alaska. The glacier occupies a narrow northeast oriented avalanche fed valley, light blue arrows indicate the avalanche feeding regions around the glacier. In 1948, as indicated in the USGS map,the glacier extended from 1600 m to 500 m, a small lake is shown at the terminus, with an overall length of 3.8 km. The glacier is a short distance southwest of the retreating Speel Glacier, and it does drain into the Speel River. Here we examine Landsat imagery of changes in this glacier from 1984 to 2013. This is a small, remote glacier that receives that has not attracted attention. It is close to the Long Lake Snotel snowpack measurement station operated by the USDA. I observed the glacier in 1998 from a helicopter and thought it did not look poised to survive our warming climate for long.
Here we examine Landsat imagery from 1984-2013 to observe glacier retreat and lake expansion. By 1984 the lake had expanded to 750 m in length, with a glacier retreat of 500 m from the mapped terminus. The snowline is marked with purple dots, the 2013 terminus with a red arrow, and the orange arrow indicates a debris covered region of the glacier. Only 20% of the glacier is snowcovered and the melt season is not yet over in the 1984 image. This same pattern of snowcover remaining is seen in 1993, 1995, 1996, 1997 and 1998 for example. By 1999 the glacier has retreated an additional 300-350 m, the snowcovered area is greater but this is an August image. In 2013 a late June and a Late July image depict the loss of snowcover during a month. The overall length of the glacier is now 2.6 km, indicating a retreat of 1200 m since and a retreat of 700 m from 1984-2013. The glacier is still terminating in the lake that has expanded by the same amount. This glacier has not only retreated but also thinned and the slopes above the glacier have greened a bit particularly on the north side. This glacier cannot survive with the level of retained snowcover it has (Pelto, 2010). Ongoing mass balance work on the Lemon Creek Glacier of the Juneau Icefield, where the Juneau Icefield Research Program is beginning measurements next week, has thinned by 29 m during the 1955-2013 period (Pelto et al, 2013). In 2014 the Long Lake Snotel site at an elevation of 850 feet, lost its snowpack on June 11, a bit earlier than normal, indicating this glacier will lose most of its snowpack in 2014.

1984 Landsat image

1997 Landsat image

1999 Landsat image

June 2013 Landsat image

July 2013 Landsat image

Yejyumaro Glacier Retreat Lake Expansion, Tibet, China

On June 19, 2014June 23, 2014 By mspeltoIn Glacier Observations

An unnamed glacier draining the west side of Yejyumaro Peak a Nepal-China border peak, into Tibet is referred to here as Yejyumaro Glacier. The glacier is at the headwaters of the Arun River, which crosses into Nepal at Kimathanka. A 335 MW hydropower plant is being planned for the Upper Arun River fed by this and other glaciers. The glacier is adjacent to Nobuk Glacier across the border in Nepal.
Google Earth images from 2002 and 2013 indicate both the glacier retreat and resulting lake expansion. Red arrow is the 1989 terminus position and yellow arrow 2013 terminus position. Notice the southern and northern arms joining and turning west. Both arms of the glacier are fed by the steep border peaks with considerable avalanching.

20002 Google Earth image

2013 Google Earth image

Landsat imagery from 1989 to 2013 is used to illustrate the response of this glacier to changing climate. In 1989 the glacier extended down the unnamed lake to a peninsula, with the lake being 2.3 km long. By 2000 the glacier had retreated from the peninsula, 150-200 m retreat since 1989. By October 2013 the glacier had retreated 700 m from the 1989 position into a narrower section of the lake. The lake is now 3 km long and still growing. A December 2013 image indicates how dry this region is during the early part of the winter with only a light snowcover across the glaciated areas and higher terrain. The last image is a the Google Earth closeup indicating the transverse crevasses that are above the terminus, the crevasses narrow moving up glacier away from the terminus and disappear 400 m above the terminus. These represent the acceleration near the calving front and the indicate that calving has helped accelerate glacier flow and glacier loss. This glaciers retreat is similar to so many in the area from Nepal such as the Nobuk Glacier that is adjacent to it in Nepal, and the many Tibetan glacier retreating along the the axis of expanding lakes, Reqiang, Matsang Tsanpo and Menlung Glacier.

1989 Landsat image

2000 Landsat image

2013 landsat image

2013 Landsat image

Google Earth closeup

Nobuk Glacier Retreat, Tamor Basin, Nepal

On June 16, 2014May 3, 2024 By mspeltoIn Glacier Observations

At the headwaters of the Tamor Basin in eastern Nepal is an unnamed glacier that terminates in an expanding glacial lake. The glacier is referred to as “Nobuk” Glacier here in reference to the nearby named peak on the map. The glacier is upstream of a Chheche Pokhari a lake formed by a glacier outburst flood in 1980. Two arms of the glacier both avalanche fed from the steep border peaks with Tibet. ICIMOD has recently finished a detailed inventory of glacier change in Nepal since 1980. In the Tamor basin they indicate glacier area from 2000 to 2010 has declined from 422 square kilometers to 386 square kilometers.
Topographic map showing lake and glacier flow paths

Google Earth image of area

Here the glacier is examined from 1989 to 2013 using Landsat images. In 1989 the lake had several developing areas amidst the decaying glacier ice, but the glacier still reached to the far eastern shore of the lake. By 2000 Nobuk Glacier terminates at a southeast turn on the south side of the glacial lake it terminates in, red arrow, 500 m from the 1989 terminus. The glacier is fed by two arms, the southern arm has a steeper icefall near the terminus and is narrower. The two arms of the glacier are separated by a buttress, marked with a Pink Point A. This buttress is 750 m from the debris covered ice front. By 2009 the glacier two arms of the glacier are separate and the southern arm no longer reaches the lake. The glacier front has retreated back to the base of the buttress at Point A. By 2013 the lake has more than doubled in length and area since 2000, red arrow at 2000 terminus in each image. The southern arm terminates 150 m from the lake and the debris covered northern arm, though still ending in the lake, it is a very thin low slope terminus that appears to be close to retreating from the lake basin that the glacier has carved. This is evident in the 2010 Google Earth image. The glacier has retreated 500 m from 2000 to 2013. The lake is now 1 km long and has an area of 0.4 square kilometers. The retreat matches that of most Nepal glaciers. This glacier was noted as shrinking from 2.3 to 1.4 square kilometers in area from 1980-2010 by the ICIMOD glacier inventory, they documented a 24% loss in area and 29% in volume during this interval For Nepal’s glaciers. Individual glacier such as Lumding, West Barun, Imja, and Ngozumpa.

1989 Landsat image

2000 Landsat image

2001 Landsat image

Landsat image 2009

Landsat image 2013

Google Earth image 2010

Nobuk Glacier Retreat, Tamor Basin, Nepal

On June 16, 2014June 17, 2014 By mspeltoIn Glacier Observations2 Comments

Google Earth image of area

2001 Landsat image

Landsat image 2009

Landsat image 2013

Google Earth image 2010

Shakes Glacier Retreat-Tributary Separation, Alaska

On June 11, 2014 By mspeltoIn alaska glacier retreat, Glacier Observations2 Comments

Shakes Glacier drains the southern portion of the Stikine Icefield and terminates in Shakes Lake. It is between the more famous LeConte Glacier to the west and Great Glacier to the east. Larsen et al (2007) indicate recent thinning of 2-4 meters per year on the glaciers along the southern margin of the Stikine Icefield. Here we utilize 1985-2013 Landsat imagery to examine changes in this glacier.

The USGS map of Shakes Glacier indicates the glacier turning the corner south along Shakes Lake. In each image the red arrow marks the 1986 terminus, the yellow arrow the 2013 terminus, the pink arrow a tributary from the east and the purple arrow a tributary from the west. In 1985 and 1986 the glacier has retreated onto the southeast trending arm of the lake ending at a deep gully on the west side of the lake, red arrow. The tributaries are still well connected to the glacier. By 1993 the glacier has retreated 300 m, the east tributary is still well connected, the west tributary at the purple arrow has considerably diminished. By 2003 the terminus has retreated 1.2 km from the 1985 position, the west tributary is just separating from the main glacier. The snowline is nearly at the top of the west tributary with a month left in the melt season. By 2011 a Google Earth image indicates the loss of connection with the west tributary and the disconnection on the east side which ends in a steep icefall slope. There is also a lake, green arrow just behind the terminus indicating impending rapid retreat will continue. The 2013 Landsat image the terminus has retreated 2.2 km from 1985, that is 78 meters/year. The lake is still evident behind the terminus. The continued significant retreat of Shakes Glacier matches that of other glaciers in the area Great Glacier, Baird Glacier, Patterson Glacier and Sawyer Glacier.
1985 Landsat image

1986 Landsat image

1993 Landsat image

2003 Landsat image

2011 Google Earth image

2013 Landsat image

Retreat of Lake No Lake Glacier Junction, Juneau Icefield, British Columbia

On June 8, 2014 By mspeltoIn Glacier Observations

Lake No Lake is a glacier dammed lake that periodically drains under the retreating Tulsequah Glacier. Canadian topographic maps indicate that three glaciers coalesced to fill this valley: Tulsequah, No Lake East and No Lake West. By 1984 when I had a chance to see this lake had formed while working on Tulsequah Glacier. Here we examine the retreat of the three glaciers that has led first to lake formation and now to a reduction in lake size from 1984-2013. In 1984 the lake extended to the terminus of No Lake East Glacier at the red arrow, after that glacier separated from the other two. Most of the valley below this point is filled with the Tulsequah and No Lake West Glacier that are still connected. The retreat of No Lake East is 1.75 km and now filled by a lake. A series of five Landsat 8 images from 2013 indicates the progression of this lake during a summer. On June 14, 2013 the No Lake East Glacier and Tulsequah Glacier are now separated with a valley 2.5 km long in between. This segment of the valley is filled by the lake, but the lake does not extend upvalley from West to East No Lake Glacier. By June 21 the lake has extended another 400 m upvalley to the northeast as the lake fills. By June 30th the lake has expanded to a length of 3 km and an average width of 600 m. By August 1st the lake has largely drained, though there are many icebergs still on the lake bottom and there is certainly some water remaining. By September 28th the lake is completely drained. The retreat of No Lake East Glacier from the 1984 terminus location at the red arrow is 450 m. The retreat of No Lake West Glacier from the yellow arrow is 400m. The 30 year retreat of the arm of the Tulsequah Glacier from the yellow to the pink arrow is 1800 m. As the damming arm of Tulsequah Glacier continues to thin this glacier will continue to decline in both depth and area. A 2010 Google Earth image is used to indicate the lake margin as indicated by stranded icebergs after drainage. Geertsema and Clague (2012) observed that this lake grew rapidly and began having glacier outburst floods during the 1970’s, but is now declining in size.
1984 Landat image

6-14-2013 Landsat image

6-21-2013 Landsat image

6-30-2013 Landsat image

8-1-2013 Landsat image

9-28-2013 Landsat image

Google Earth image, yellow dots lake outline

Sacagawea Glacier, Wyoming is Disappearing

On June 2, 2014 By mspeltoIn Glacier Observations2 Comments

Sacagawea Glacier in the Wind River Range of Wyoming lost 35% of its area between 1966 and 2006. This glacier on the west slope of Sacagawea Peak and Helen Peak and just north of Upper Fremont Glacier. Here we compare Google Earth imagery of the glacier that indicates the change during this forty year period. In 1966 the glacier had an area of square kilometers. The first image is the USGS map of the glacier from 1966 imagery. The orange outline is the glacier margin at this time and the red outline the 2006 glacier boundary. By 1994 Google Earth images indicate a retreat of 270 m along its main terminus. A small lake has also begun to form along the southern section of the terminus. The northern section of the glacier below Helen Peak had by 1994 become practically disconnected from the main section of the glacier. In 1994 the exposed blue ice area is extensive, indicating that most of the glacier was consistently losing its snowcover. With retained snowcover limited to the steeper slopes above 3700 m. By 2006 the lake was 400 m long and 150 wide along the southern section of the terminus. The terminus retreat along the main terminus averaged 350 m since 1966. The northern section of the glacier is fully detached from the rest of the glacier. The fraction of snowcovered area is 10% in 2006, which was typical for the 2003-2006 period. This is insufficient to maintain a glacier, the snowcovered area for temperate alpine glaciers such as the Sacagawea that lacks extensive avalanching is 55-65 % snowcover at the end of the melt season. The locations marked with Point A in red are locations where rock formerly beneath the glacier has been exposed as the glacier melted from that location. By 2013 a Landsat image of the glacier indicates that the glacier is beginning to recede from the terminus lake, further that there is almost no retained snowcover in 2013 and that the glacier is separated into three segments note the yellow arrows. The upper margin of the glacier is receding which indicates thinning in the accumulation zone, an indicator that this glacier does not have a significant accumulation zone and cannot survive current climate (Pelto, 2010). In a Planet Action Project Pelto (2010)reported that 2/3 of the 15 Wind River glaciers examined were not going to survive current climate. This includes Minor Glacier, Sourdough Glacier, Grasshopper Glacier and Lower Fremont Glacier.
1966 USGS map

1994 Google Earth

2006 Google Earth

2013 Landsat Image

Analysis of Sacagawea Glacier and Upper Fremont Glacier, Wind River Range, Wyoming

Haworth Glacier Retreat, Selkirk Mountains, British Columbia

On May 30, 2014 By mspeltoIn Glacier Observations1 Comment

Haworth Glacier in the northern Selkirk Mountains of British Columbia drains into Palmer Creek, which flows into Kinbasket Lake, and then the Columbia River. This glacier is often visited by climbers as the Canadian Alpine Club has a summer base camp near the terminus of the glacier. The glacier has a low slope and limited crevassing that makes it a good training ground for climbing. Menounos et al (2008) noted an advance of this glacier overrunning a stump that has since been exposed by retreat in the period from 3800 years before present, similar in timing to many glaciers in the region. The stump remained buried until recent exposure.

Here we examine a series of Landsat images from 1986-2013 to identify the retreat and forecast whether the glacier can survive even current climate conditions. In each image the blue dots mark the snowline, yellow arrow is the 1986 terminus and the red arrow the 2013 terminus. In 1986 the glacier ended near the far end of the basin where a lake has since developed, yellow arrow. Snowcovers 30% of the glacier in the late summer of 1986, 55-65% is necessary for glacier equilibrium. By 1994 the glacier had retreated exposing the new lake basin, the glacier was 25% snowcovered. By 1998 the glacier had retreated 550 m since 1986, the glacier was 15% snowcovered. In 2009 the glacier was 20% snowcovered. In 2013 the glacier terminates at the red arrow indicating a retreat of 1000 m since 1986, 37 m per year. The glacier is 10% snowcovered. The percent snowcover in each year is much less than the 55% minimum needed for a minimum balance, the images are also not precisely at the end of the melt season. If a glacier does not have a consistent and persistent snowcover at the end of the melt season it has no “income” and cannot survive (Pelto, 2010). This glacier has managed to retain a very small area of snowcover, but given the ongoing thinning and the lack of avalanche accumulation on this glacier, it is unlikely to be enough to save this glacier. Bolch et al (2010) noted a 10% area loss for British Columbia glaciers from 1985 to 2005, Haworth Glacier is above this average. Tennant and Menounos (2013) noted that the fastest rate of loss on Columbia Icefield glaciers from 1919-2009 was during the 2000-2009 period. The glacier is not retreating as fast as some of the glaciers that also calve into lakes such as Columbia Glacier, British Columbia. Nearby Apex Glacier has retreated at a similar rate. Jiskoot et al (2009) observed the terminus change of 176 glaciers in the Clemenceau Icefield and adjacent Chaba Icefield, and noted an average retreat of 21 meters per year from the 1980’s to 2001.

1986 Landsat image

1994 Landsat image

1998 Landsat image

2009 Landsat image

2013 Landsat image

Kwadacha Provincial Park Glacier retreat, British Columbia

On May 28, 2014 By mspeltoIn Glacier Observations

Kwadacha Wilderness Provincial Park in Northern British Columbia is host to numerous glaciers. Here we focus on an unnamed glacier that drains north into the Kechika River, which joins the Laird River. This glacier straddles both a watershed divide. The map of the glacier indicates the three separate termini of this glacier. Bolch et al (2010) noted that this area of BC lost 15% of its glacier area from 1985 to 2005. A comparison of Landsat imagery and Google Earth imagery during the 1994-2013 period indicate the changes to this Kwadacha Park glacier. In 1994 the glaciers three termini are at the red-northern terminus, yellow-southeaster terminus and orange-southwestern terminus arrows. A separate glacier ends at the margin of an alpine lake at the violet arrow. In 1995 there is no snowcover retained on the glacier. In 2001 the terminus at the orange arrow has retreated leading to lake expansion and at the red arrow. By 2013 the glacier’s northern terminus has retreated 250-300 m since 1994 and now terminates at the end of a rock rib. The southeastern terminus has retreated 250 m losing most of this glacier tongue. The southwestern terminus has retreated 300 m, and some calving is occurring. The glacier also has no retained snowpack in 2013. A glacier that consistently loses all of its snowpack cannot survive (Pelto, 2010). This glacier falls into that category. The retreat is evident in the Google earth image with the arrows marking the 1994 terminus locations. A closeup of this image indicates the lack of retained snowcover, blue dots mark snowline. The southwestern terminus calving margin is noted at the green arrow. The near stagnant nature of the northern terminus is also evident with the lack of crevassing. This glaciers will continue to thin and retreat and with current climate will not survive. The retreat is similar to that of other glaciers in the region including Snowshoe Glacier, Yukon, Great Glacier and Freshfield Glacier.

1994 Landsat image

1995 Landsat image

2001 Landsat image

2013 Landsat image

2013 Google Earth image

Dead Branch of Norris Glacier Decay, Alaska

On May 24, 2014 By mspeltoIn Glacier Observations1 Comment

The Dead Branch of the Norris Glacier is a side valley of the Norris Glacier fed by the main glacier. Instead of tributary it is a distributary tongue. As the Norris Glacier has thinned and retreated 100 m from 1984-2013 recently the inflow had declined. The Dead Branch has retreated and a subglacial lake forms each spring that lifts the glacier causing concentric crevasses to form. The lake then drains later in the summer and the glacier subsides. The crevassing has gotten much worse since I first saw this glacier in 1984. Here we look at Landsat and Google Earth imagery from 1984-2013.

Below is a sequence of three images from 2010 indicating the key feature in the center of the glacier. This dark feature, purple arrow amidst the snow covered glacier in July is caused by large crevasses due to glacier uplift by the sub-glacial lake. The water table rises to near the glacier surface bringing with it sediment that then stains the surrounding snow it infiltrates. There is one large north trending crevasse that connects to a lake that is partly on and partly adjacent to the Dead Branch. The next two images are closeups. The concentric crevasses and radial crevasses, that look like spokes, are indicative of lake uplift in this otherwise flat stagnant reach of the glacier. The expansion of this network suggests that the thinning glacier is easier to lift over a larger area.

Google Earth 2010 image

2010 Closeup annotated- rred arrow concentric crevasses, blue arrow main connection crevasses, purple arrows radial crevasses.

2010 Digital Globe

The set of images below are from Landsat images from 19884-2013 the yellow arrow indicates the western terminus of the glacier tongue. This has retreated 400-500 m during this period. The red arrows indicate two prominent features on the side of the glacier which indicate that there is some thinning and lateral retreat, though not nearly as much as on the feeder Norris Glacier. The large crevasses do not show up well in the late summer 2013 Landsat as the lake has drained and the glacier subsided closing many, and due to the reduced resolution of the image. This branch is similar to that of the Witches Cauldron of Baird Glacier. Both appear poised to expand into large lakes in isolated valleys. In early summer 2014 we will closely watch the lake formation and glacier response .

1984 Landsat image

1998 Landsat image

2013-July Landsat image

2013-September Landsat image

Mittelaletsch Glacier Retreat, Switzerland

On May 18, 2014 By mspeltoIn Glacier Observations

Mittelaletsch Glacier was a tributary to the Alps largest glacier Grosser Aletsch, until separation in 1990. The map of the glacier represents changes in the glacier from 1926 to 1957, indicating the connection of the two glaciers at that time. By 1970 Mittel had separated from Grosser, and experienced 420 m of retreat from 1970 to 2000 as noted by the Swiss Glacier Monitoring Network.
Map showing 1957 glacier extent with elevation changes from 1926 in yellow.

Here we examine changes in the glacier using Landsat imagery from 1990 to 2013. In each image an upper and lower green arrow point to the same location where expanding bedrock areas are separating the upper and lower portion of the glacier. Point A is at the lower end of a prominent rock rib. In 1990 the glacier ends at the red arrow separated from Grosser Aletsch by 600 m. At the lower green arrow the glacier is flowing across this slope contributing snow and ice to the lower glacier. In 1999 the area of exposed bedrock between the upper and lower glacier has expanded by at least 500 m at both green arrows. By 2007 Google Earth imagery indicates a continued expansion at the lower green arrow. The glacier terminates at the yellow arrow 1050 m from a connection to the Grosser Aletsch Glacier. The lower 1 kilometer of the glacier is stagnant as seen in the closeup view of the terminus, pink arrow indicates start of stagnant section. In 2013 the glacier has retreated 1400 m from the Grosser Aletsch Glacier, terminating at yellow arrow versus 1990 terminus red arrow. The margin of the Grosser Aletsch has contracted 150-200 m, hence the actual retreat since separation is 1200-1250 m. By 2013 at the lower green arrow the bedrock strip separating this section of the upper and lower glacier has expanded to a length of 1 km. This is equivalent to a company losing income from an important division, or a family losing one income stream. The lower glacier is recieving less snow and ice contribution and will continue to retreat, quickly loseing the stagnant area the comprises the lowest 700-100 m of the glacier. Jouvet et al (2011) reconstruct the behavior of the Aletsch Glacier system to various climate scenarios and find that any scenario leads to 2 km of retreat by 2040 for Grosser Aletsch and somewhat less for Mittelalestch. This glaciers behavior is similar to that of nearby Gauli and Oberaar.
1990 Landsat image