Bernardo Glacier, Patagonia, Chile Accelerated Retreat in Expanding Lake Complex

On May 23, 2016May 2, 2024 By mspeltoIn chile glacier melt, chile glacier retreat, climate change glacier retreat, glacier climate change, Glacier Observations1 Comment

Comparison of 1986 and 2015 Landsat image of Bernardo Glaciers three termini, north, main and south. Red arrows indicate 1986 terminus location and yellow arrows the 2016 terminus location. Indicating the substantial retreat of each terminus and lake expansion for the north and main terminus, while the lake drained at the southern terminus.

Bernardo Glacier is a difficult to reach outlet glacier on the west side of the Southern Patagonia Icefield (SPI). It The glacier currently ends in an expanding proglacial lake system, with three primary termini. Here we examine changes from 1986 to 2016 using Landsat images. Willis et a (2012) quantify a rapid volume loss of the SPI from 2000-2012 of 20 giga tons per year mainly from rapid retreat of outlet glaciers. They note a thinning rate of 3.4 meters per year during this period of the Bernardo Glacier region. Mouginot and Rignot (2014) illustrate that velocity remains high from the terminus to the accumulation zone on Bernardo Glacier. They also indicate the accumulation zone does not extend as far east toward the crest of the SPI as previously mapped. Davies and Glasser (2012) indicate that over the last century the most rapid retreat was from 2000 to 2011.

In 1986 Bernardo the southern terminus of the glacier was nearly in contact with Tempano Glacier. The main terminus primarily ended on an outwash plain with a small proglacial lake developing. The northern terminus had retreated a short distance south from a peninsula. By 1998 the northern terminus had retreated into a wider, deeper lake basin, filled with icebergs. The main terminus is still mainly grounded on an outwash plain. A small lake has developed between Bernardo Glacier and Tempano Glacier to the south. By 2003 the northern terminus had retreated 2 km from 1986, the main terminus 1.5 km and the southern terminus 1.2 km. By 2015 the lake between Tempano and Bernardo Glacier had drained. The main terminus had retreated 1.5 km since 1986. In 2016 the northern terminus had retreated 3.5 km since 1986, the main terminus 2.5 km and the southern terminus 2.75 km. The largest change is the loss of the lake between Tempano and Bernardo Glacier which slow the retreat of the southern terminus. If this terminus retreat into the another lake basin that shared with the main and north terminus, this would likely destabilize the entire confluence region. The nearly 1 km retreat in a single year from 2015 to 2016 of the main terminus indicates the instability that will lead to further calving enhanced retreat. The retreat of this glacier fits the overall pattern of the SPI outlet glaciers, for example Chico Glacier and Lago Onelli Glaciers

1998 Landsat image. Red arrows indicate 1986 terminus location and yellow arrows the 2016 terminus location.

2003 Landsat image. Red arrows indicate 1986 terminus location and yellow arrows the 2016 terminus location. Main terminus beginning to retreat from outwash plain.

2015 Landsat image. Red arrows indicate 1986 terminus location and yellow arrows the 2016 terminus location. Note the considerable difference in main terminus versus one year later in 2016.

North Fork Grand Plateau Glacier, Alaska-Spectacular 3 km Retreat 2013-15

On May 1, 2016May 2, 2024 By mspeltoIn alaska glacier retreat, climate change glacier retreat, glacier climate change, Glacier Observations1 Comment

North Fork Grand Plateau Glacier comparison in 2013 and 2015 Landsat images. Illustrating the rapid retreat and lake expansion in just two years. Pink arrow is 1984 terminus, red arrow is the 2013 terminus and yellow arrow 2015 terminus. The orange dots are the 2013 terminus.

The Alsek Glacier is a large glacier draining into Alsek Lake and the Alsek River in southeast Alaska Its neighbor the Grand Plateau Glacier has one fork flows north and joins the Alsek Glacier terminating in Alsek Lake. The USGS topographic map compiled from a 1958 aerial image indicates a piedmont lobe spread out into a proglacial lake that is less than 3 km wide, with a combined ice front of the Alsek Glacier and North Fork Grand Plateau Glacier.. There is a 10.5 km wide calving front in the lake. By 1984 the glacier had separated into a northern and southern calving front on either side of an island and had a 13 km wide calving front. Here we focus on the southern lobe, which is comprised of a lobe of the Alsek Glacier and a the North Fork Grand Plateau Glacier that merges with Alsek Glacier. From 1984 and 1999 the two lobes separated as the North Fork retreated 2.2 km. From 1999 to 2013 the North Fork retreated 1.5 km up a newly forming southern arm of Alsek Lake. The retreat over the 30 period of 3.7 kilometers averaged ~120 meters/year. Landsat imagery in 2013 and 2014 indicate extensive calving from the North Fork Grand Plateau Glacier. From 2013 to 2015 the terminus has retreated 3.0 km, 1.5 km/year. This is likely the fastest retreat rate in recent years of any Alaskan glacier. The calving front in Alsek Lake has been reduced to 5.4 km in three separate sections.

The retreat has been similar in timing to nearby Alsek River watershed glaciers Walker Glacier, East Novatak Glacier and North Alsek Glacier.. The rapid retreat is enhanced by calving in proglacial lakes, a common issue increasing area loss of Alaskan glaciers. Yakutat Glacier is an example of rapid lake expansion. In the case of Yakutat Glacier unlike the Alsek or Grand Plateau Glacier the glacier lacks any high elevation accumulation zone and cannot survive without an accumulation zone (Trüssel et al 2015). Grand Plateau Glacier and Alsek Glacier both have large accumulation areas above 2000 m, that are well above the snowline at all times. The Alsek River is a destination for sockeye salmon fishing and river rafting, see Chilkat Guides or Colorado River and Trail Expeditions. Continued expansion of lake area as glaciers retreat in the watershed, is changing the nature of the Alsek River.

USGS Topographic map of region from 1958 aerial images indicating merging of Alsek Glacier and North Fork Grand Plateau Glacier.

1984 Landsat image indicating terminus locations. Pink arrow is 1984 terminus, red arrow is the 2013 terminus and yellow arrow 2015 terminus.

1999 Landsat image indicating terminus locations. Pink arrow is 1984 terminus, red arrow is the 2013 terminus and yellow arrow 2015 terminus.

2014 Landsat image. indicating terminus locations. Orange dots indicate the ice front. Pink arrow is 1984 terminus, red arrow is the 2013 terminus and yellow arrow 2015 terminus.

Krayniy Glacier Retreat, Novaya Zemlya

On April 28, 2016May 2, 2024 By mspeltoIn glacier climate change, Glacier Observations, Novaya Zemlya glacier retreat

Krayniy Glacier (Ky) comparison in 1990 and 2015 Landsat images. Red arrow is 1990 terminus and yellow arrow is the 2015 terminus. Purple arrows indicate upglacier thinning and green arrow a location of a glacier dammed lake.

Krayniy Glacier is an outlet glacier that drains the northern side of the Novaya Zemlya Ice Cap into the Barents Sea. This outlet glacier is just southwest of Tasija Glacier (T) and like that glacier has retreated over 1.2 km since 1988. Krayniy Glacier has been retreating like all tidewater glaciers in northern Novaya Zemlya (LEGOS, 2006). The terminus of the glacier has a pinning point on an island at present. Carr et al (2014) identified an average retreat rate of 52 meters/year for tidewater glaciers on Novaya Zemlya from 1992 to 2010 and 5 meters/year for land terminating glaciers. The increased retreat rate coincides with the depletion of ice cover in the Barents Sea region and a warming of the ocean. Both would lead to increased calving due to more frontal ablation and notch development similar to at Svalbard (Petlicki et al. 2015). The spring of 2016 features an ice free west coast of Novaya Zemlya leading to enhanced calving front melting.

In 1990 the glacier had an east west terminus across the head of the fjord. There was a substantial glacier dammed lake impounded by the glacier (green arrow), and there was a narrow connection with Tasija Glacier. The glacier dammed lake persisted in Landsat images in 1999, 2000, 2003 and 2006. In 2013 the proglacial lake had drained. In 2014 and 2015 the lake has not reformed, an indication of glacier thinning at the outlet location. This thinning is evident at both purple arrows,where the connection with the Tasija Glacier has been severed and a substantial nunatak has emerged amidst the glacier. From 1990 to 2015 the glacier has retreated more on the eastern margin with 1250 of retreat opening up the embayment. Retreat at the island in the glacier center has been 500 m since 1990. The western section of the glacier has retreated little. The eastern embayment will continue to drive retreat and glacier thinning that will reduce contact with the island pinning the eastern half of the glacier. The thinning is evident at the purple arrows. The glacier will likely retreat from this island in a fashion similar to Tasija and Chernysheva, which will lead to increased rate of retreat of the entire ice front.

1988, 2006 and 2014 Landsat images indicating the continued presence of glacier dammed lake from 1988-2006 and continued absence from 2014 and 2015.

Sea ice image from Cryosphere Today

Pacific Northwest Glaciers: Widespread early Melt Season Arrival

On April 24, 2016May 2, 2024 By mspeltoIn alaska glacier retreat, Canada glacier retreat, glacier climate change, Glacier Observations

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The 2016 melt season is off to an early start in Greenland, but this is not the only location. This winter proved to be warm, but relatively wet across much of the Pacific Northwest. A look at the average freezing level (determined by North American Freezing Level Tracker-Developed by John Abatzoglou and Kelly Redmond) from January 1 to April 20 indicates freezing levels well above average on Mount Baker North Cascades, Washington, Bugaboo Mountains British Columbia and Juneau Icefield Alaska. Reports from the field in British Columbia, Alaska and Washington identify a peak snowpack in late March instead of early May at glacier elevations.

In British Columbia the University of Northern British Columbia field team is currently on Conrad Glacier in the Bugaboos, having just finished Kokanee Glacier. This is part of a five-year study led by Dr. Brian Menounos, UNBC Canada research chair in glacier change, funded by the Columbia Basin Trust. UNBC PhD student Ben Pelto heads the research team. They have found that despite snowpack observations for the region from the BC River Forecast Centre of slightly above average snowpack on April 1, the high winter freezing levels and very warm April conditions have left the Kokanee Glacier snowpack quite similar to the low 2015 snowpack, with close to 4.5 m of retained snowpack. The snowmelt season was noted by the River Forecast Centre as starting several weeks early. The freezing level from January-April 20 was a record for the 1948-2016 period by over 100 m for the Bugaboo mountains. The region based on the warm spring causing rapid snow melt at lower elevations is leading many, Including John Pomeroy, to expect high forest fire danger and low streamflow during the summer across the Western Canada.

Snowpit being excavated on Zillmer Glacier April 2016, Jill Pelto and Micah May. (Ben Pelto)

Jill Pelto and Ben Pelto measuring density of firn core on Kokanee Glacier. (Tom Hammond)

In Alaska USGS-Glaciology has been completing GPR surveys of their benchmark glaciers in recent weeks. On the Juneau Icefield Lemon Creek Glacier is a reference for the World Glacier Monitoring Service. Mass balance records exist since 1953 for this glacier (Pelto et al, 2013). In April the glaciers are typically covered head to toe by snow. The last four months indicate a freezing level of nearly 900 m a record for the 1948-2016 period of record. An April 19th Landsat image indicates the snowline on Herbert and Mendenhall Glacier at 600 m. This is below the terminus of Lemon Creek Glacier at 800 m. Near the Juneau Icefield the Long Lake Snotel site at 260 m in elevation had its snowpack drop from 64 cm water equivalent to 38 cm water equivalent in the last month.

USGS Wolverine Glacier Base Camp last week with field work underway.

April 19 Landsat image of the southwest side of the Juneau Icefield. Snowline indicated by Purple arrows. M=Mendenhall, H=Herbert, L=Lemon Creek and T=Taku Glacier.

For Mount Baker, Washington the freezing level from January-April 20 was not as high as the record from 2015, but still was 400 m above the long term mean. Observations at the base of Easton Glacier, one of our key glaciers in the North Cascades, indicate that the snowpack has declined from a depth of 4.8 m to 3.4 m during the first three weeks of April. This is mainly due to compaction, versus snow water equivalent loss, but still represents the rapid densification that occurs as snowmelt begins in earnest.

April 2016 image from icefall on Easton Glacier at 2500 m above (Adam Dunn) and in August below same area (Jill Pelto).

Belopolskijbreen Retreat Generates Terminus Split, Svalbard

On April 20, 2016May 2, 2024 By mspeltoIn glacier climate change, Glacier Observations, svalbard glacier retreat

Belopolskijbreen comparison in 1990 and 2014 Landsat images. Red arrow is the 1990 terminus location, yellow the 2014 extent of the a bedrock ridge separating the two lobes of the glacier, and purple arrow an area of thinning at the head of the glacier.

Most of the attention on Svalbard glaciers goes to the larger tidewater glaciers, which collectively having been losing volume rapidly. Belopolskijbreen in Sorkappland near the southern tip of Svalbard a land based glacier that we examine here using Landsat images from 1990 to 2014. The glacier is adjacent to Olsokbreen a rapidly retreating tidewater glacier. In 1990 and in the TopoSvalbard maps indicate the glacier terminating in proglacial lakes A and B. The snowline is restricted to the very top of the glacier. With limited retained snowpack anywhere, the glacier will thin and retreat significantly. In the middle of the glacier near the red arrow is a bedrock ridge that 700 m into the glacier. By 2014 the bedrock ridge has extended to the yellow arrow, an additional 700 m. The glacier has retreated 500 m from Lake A and 650 m from Lake B. The retreat of approximately 500 m across a 4 km wide glacier front plus the expansion of bedrock in the middle, represents more than 2 square kilometers of area lost. This retreat will continues as the snowline has been limited to the very top of the glacier in 2013, 2014 and 2015. The 2013 Landsat image below indicates the snowline with purple dots. The snowline is above 375 m with the top of the glacier at just over 400 m. The glacier has 10% snowcover retained at a maximum, the minimum needed for equilibrium is 50%.

Nuth et al (2013) determined that the glacier area over the entire archipelago has decreased by an average of 80 km²per year over the past 30 years, a 7% reduction. In the most recent period 1990-2007, terminus retreat was larger than in an earlier period from 1930-1990, while area shrinkage was smaller. Svalbard is host to 163 tidewater glaciers with a collective calving front of 860 km (Błaszczyk et al, 2009). Blaszczyk et al. (2013) reported the total area of the glacier cover lost in Hornsund Fjord area from 1899–2010 was approximately 172 square kilometers, which is just north of Sorkappland.

TopoSvalbard map of Belopolskijbreen, terminating at Lake A and B. Red arrow marks ridge separating glacier terminus into two lobes.

2013 Landsat images. Note the snowpack limited to the very top of the glacier, purple dots

Goddess of Light (Kolahoi) Glacier Showing Mortality, Kashmir Retreat 1993-2015

On April 14, 2016May 2, 2024 By mspeltoIn glacier climate change, Glacier Observations, Himalaya glacier retreat4 Comments

Kolahoi Glacier comparison in Landsat images from 1993 to 2014. Kolahoi Glacier is the northern glacier, East Kolahoi Glacier the other noted glacier. Red arrows indicate 1993 terminus locations, and yellow arrows the 2014 terminus locations.

The Kolahoi Glacier in Kashmir is known as the—”goddess of light”—Gwash Brani (NatGeo, 2010). The glacier descends the north side of the mountain with two tongues of the glacier merging above the terminus in 1993. The glacier drains into the Liddar River and then the Jhelum River system. The Jhelum River has several large operating hydropower stations and several more under construction including the Karot Hydropower Project a 720 MW run of river project. Jeelani et al (2012) observed that the Liddar Watershed derives 60% of its runoff from snowmelt and just 2% from glacier ice melt. They further report that the Liddar watershed has 17 glaciers covering an area of 40 km² in 2008. The climatic warming in the region has led to mass wasting of Kolshoi Glacier and retreat. From 1970 to 1990 there was a cooling trend of about −0.02°C per year followed by the time period from 1991 to 2010 with the highest increasing trend of 0.07°C per year (Jeelani et al 2012) . Tayal (2011) observed the detachment of the two glacier branches and a loss of 2-3.5 m of ice thickness due to ablation in the lower reach of the glacier.

Hydropower Projects in Jhelum Basin.

From 1993 to 2001 there is limited retreat of Kolahoi Glacier and East Kolahoi Glacier, though both glacier fronts become narrower. By 2006 Kolahoi Glacier has retreated to near the base of a steeper slope. The glacier remains heavily crevassed in the region above the icefall within 1 km of the terminus, Point A. By 2014 the glacier has retreated to the top of the steeper slope between two bedrock knobs at 3650 m, total retreat from 1993 to 2014 is 700 m. Crevassing above the slope, at Point A, that used to be an icefall has become limited since 2006 and before. The reduction in velocity indicates retreat will continue. The western tributary of the Kolahoi has developed a separate termini from the main glacier after 2001, single vertical red arrow.. The East Kolahoi Glacier has retreated 300 m. The lower 300 m of Kolahoi Glacier is thin and relatively uncrevassed. This indicates the retreat will continue. This region has its highest precipitation from January through April and highest runoff in June and July. Hence, the glacier is not a summer accumulation type like glaciers to the east in the Himalaya. The retreat is similar to that of Samudra Tupa Glacier and Durung Drung Glacier.

Google Earth image from 2014 of Mount Kolahoi and its main glaciers flow directions indicated.

2001 Landsat image of Kolahoi Glacier

2015 Landsat image of Kolahoi Glacier

Google Earth image of the terminus area outlined in blue of Kolahoi Glacier in 2006 and 2014.

Image of the terminus of Kolahoi Glacier in 2010 from Jellani et al (2012)

Nansen Ice Shelf, Antarctica Calving Event Occurs April 2016

On April 11, 2016May 2, 2024 By mspeltoIn Antarctic Glacier retreat, Glacier Observations1 Comment

Nansen Ice Shelf just north of Dryglaski Ice Tongue on April 2 with evident rift,blue arrows, and after calving two icebergs on April 7, A and B. Images from NASA MODIS

The NIWA reported a calving event from the Nansen Ice Shelf on April 11, 2016. They are concerned about a mooring in Terra Nova Bay in front of the ice shelves. The area of the Nansen Ice Shelf is 1500 square kilometers, these icebergs have a combined estimate of approximately 250 square kilometers. This is a substantial calving event for such a small system. Below is an image of the Nansen Ice Shelf on January 1, 2014 and January 1, 2016. This illustrates the Terra Nova Bay polyna that develops every summer, and affects sea ice dynamics, and certainly the ice shelf. The former lacks a notable rift, the latter exhibits the rift that would lead to calving, the rift had formed in late 2013, but is still not evident in imagery of the resolution of MODIS. NIWA had been watching this expanding rift for signs of calving. NASA had warned in March that calving was imminent and had been monitoring the ice shelf to determine the affect of tides on the ice shelf dynamics. The rift is beautifully shown by NASA in its growth from 2013 to 2015. Such rifting and calving can be part of stable dynamics as on Stange Ice Shelf or an indicator of instability as in the case of Verdi Ice shelf.

Nansen Ice Shelf in January 2014 and January 2016.

Google Earth image of the region in 1999 indicating several significant rifts.

North Cascade Winter Snowpack 2016, 33rd Field Season Approaches

On April 10, 2016May 2, 2024 By mspeltoIn glacier climate change, Glacier Observations, North Cascade Glaciers

This 2016 winter has proved much different than in 2015. In 2015 exceptional warmth led to record low snowpack despite above average precipitation. The warmth is illustrated using the North American Freezing Level Tracker for our Sholes Glacier site. The highest mean level by far is 2015, 500 m above average versus 180 m above average this winter. The low snowpack combined with a long warm melt season in 2015 led to the highest mass losses from North Cascade glaciers in our 32 years of observations.

Freezing Levels for the November-March period at Sholes Glacier in the North Cascades.

A key date for snowpack assessment has always been April 1. As a result there is good data set from six of the invaluable USDA SNOTEL sites in the North Cascades since 1946. A comparison of snowpack water equivalent (SWE) and total precipitation yield a ratio of SWE retained on April 1 to total precipitation. The result is the ratio between SWE and precipitation, snowpack storage efficiency has been in decline, as noted by Mote et al (2008) and Pelto (2008). The best long term precipitation stations in the region are Diablo Dam and Concrete, we use the average of the two. The storage efficiency ratio was a minimum in 2015 at only 19% of precipitation retained as snowpack. In 2016, 43% of precipitation has been retained leading to snowpack that is 10% above the mean for the 1984-2015 period.Winter precipitation over the period has a positive trend and SWE a negative trend. This declining ratio led Jon Riedel of the North Cascades National Park Service to observe that we now need 120% of average precipitation to achieve average snowpack. It is interesting to note that 2014, 2015 and 2016 had quite similar November-March total precipitation. With 2016 slightly exceeding 2014 for snowpack.

In 2014 the glaciers had a poor year, not due to low snowpack but to high melt season temperatures. What will transpire in 2016 will be the focus on our 33rd consecutive annual field season monitoring North Cascade glaciers. In the last 10 days warm weather in the region has led to significant snowpack melt. At low elevation sites snowpack depth and SWE have decreased by 20% at sites like Trinity 2930 feet. Just 10 miles away at Lyman Lake at 5980 feet the snow depth decreased from 170 inches to 142 inches, but SWE has not declined. As is typical this early snowmelt period leads to percolation and either refreezing or storage within the snowpack. This is still an important ripening that must occur before SWE can drop. Typically SWE reaches a maximum at the elevations of glaciers between May 1 and 10. A 10 day warm period as has occurred may indicate an early peak, but April could also feature more snow storms that will lead to future increases. From Alaska to British Columbia to Washington groups are heading into the field to assess snow depth on glaciers at the end of this winter season. Snowpits, snow stakes emplaced last last summer and Ground Penetrating Radar will all be deployed.

Trends in winter precipitation November-march in the North Cascades , average of Concrete and Diablo Dam. Mean SWE at six USDA SNOTEL station on April 1 (Fish Lake, Lyman Lake, Park Creek, Rainy Pass, Stampede Pass and Stevens Pass). Ratio of April 1 SWE and winter precipitation.

Mean SWE at six USDA SNOTEL station on April 1 (Fish Lake, Lyman Lake, Park Creek, Rainy Pass, Stampede Pass and Stevens Pass.

Assessing snow depth on Easton Glacier using crevasse stratigraphy.

Image above of Glacier Peak and below of Monte Cristo Peaks in the North Cascades on April 9, 2016 from a trip to Bedal Peak by raising3hikers at NWHikers.net. The blanket of snow remains deep.

Neumayer Glacier, South Georgia, 5.6 km retreat 1999-2016

On April 5, 2016May 2, 2024 By mspeltoIn glacier climate change, Glacier Observations, south georgia glacier retreat

Comparison of Neumayer Glacier in 1999 and 2016 Landsat images; red arrow indicates 1999 terminus locations, yellow arrows 2016 terminus locations. Purple arrows indicate upglacier thinning.

South Georgia sits amidst the circum Antarctic westerlies and its maritime climate leads to numerous glaciers. This region is famous for the endless march of storms parading around Antarctica . The island is south of the Antarctic Convergence, preventing any truly warm season from persisting. The cool glaciers covering a majority of the island and quite low equilibrium line altitudes. Neumayer Glacier is one of the largest tidewater glaciers on South Georgia. Sugden, Clapperton and Pelto (1989) noted the ELA of Neumayer Glacier at 550 m.

The BAS has a mapping function that provides glacier front positions since early in the 20th century. For Neumayer Glacier the 1938 position is 3.5 km down fjord from the 2006 position. There was essentially no retreat up to 1974 and limited retreat up to 1993. Gordon et al., (2008) observed that larger tidewater and sea-calving valley and outlet glaciers generally remained in relatively advanced positions until the 1980s. After 1980 most glaciers receded; some of these retreats have been dramatic.

Landsat Images from 1999 to 2016 indicates retreat of 5600 m from the red to the yellow arrow, this is 350 m/year. A glacier dammed lake along the north shore of the fjord no longer exists in 2016. The glacier appears to have retreated into a deeper section of the fjord then where it ended from 1970-2002. The glacier is on the verge of separation into two main tributaries. This will enhance calving from the glacier, and promote additional mass loss and retreat. This retreat will impact Konig Glacier to the north, which is connected to the Neumayer Glacier. Below the comparison of terminus location from 1989 to 2015 indicates a retreat of 6700 m. NASA Earth has piggy backed on this assessment, with excellent recent imagery. Calving rate increases with water depth. Calving rate increases with water depth and the degree of glacier flotation. Flotation depends on water depth, ice thickness and the number of pinning points. Pelto and Warren (1991) provided an expanded version of the water depth/calving relationship first quantified by Brown and others (1982). In the you would have never guessed it category, is the glacier retreat has been an aid to the rat population, as the glacier tongues used to corner populations.

BAS Glacier front map

Comparison of Neumayer Glacier in 1989 and 2015 Landsat images; red arrow indicates 1989 terminus locations, yellow arrows 2015 terminus locations.

New Zealand Glacier Change Index

On March 24, 2016May 2, 2024 By mspeltoIn glacier climate change, Glacier Observations, New Zealand glacier3 Comments

Terminus of Tasman, Mueller and Hooker Glacier terminus in Mount Cook 1972 map, no lake present.

Progalcial lakes forming in front of Tasman, Mueller and Hooker Glacier in 1990 above and 2015 Landsat images below.

Red arrows are the 1990 terminus and yellow arrows the 2015 terminus locations.

Overview

The Southern Alps of New Zealand are host to over 3000 glaciers that owe their existence to high amounts of precipitation ranging from 3 to 10 m (Chinn, 1999). The list below examines the changes of 12 glaciers examined in a separate post. The NIWA glacier monitoring program has noted that volume of ice in New Zealand’s Southern Alps has decreased by 36% with the loss of 19.0 km³ of glacier ice, from 53.3 km³ in 1978 to 34.3 km³ in 2014 (New Zealand Govt., 2015). Volume loss in New Zealand glaciers is dominated by 12 large glaciers (Salinger and Willsman, 2008). More than 90% of this loss is from 12 of the largest glaciers in response to rising temperatures over the 20th century (Chinn, 1999). In the 1972 map of the region there is no lake at the terminus of the Tasman Glacier, Mueller Glacier or Hooker Glacier; each are substantial in size by 2015. Each lake continues to expand and as glacier retreat continues .From 1977-2015 NIWA has conducted an annual snowline survey, in six of the last nine years the snowline has been significantly above average and three years approximately at the average (Willisman et al., 2015). This has driven the widespread glacier retreat underway. In each case the retreat of the largest glaciers has been enhanced by the formation and expansion of lakes, in this newly developing lake district. Dykes et al., (2011) identify the role of glacier lakes in accelerating the retreat of Tasman Glacier. The retreat of these glaciers has until recently been slowed by debris cover and the long low slope ablation zone segments (Chinn, 1999). Glaciers that lack debris cover and have a steeper slope have a more rapid response time, such as Fox Glacier and Franz Josef Glacier (Purdie et al., 2014). These two glaciers have been in the news of late due to rapid retreat causing glacier tours of the lower reaches of the glacier unsafe. NIWA reported that February of 2016 was the second warmest month of any month in New Zealand, which will drive snowlines higher and enhance glacier melt this year.

Many New Zealand glaciers are important for hydropower: Lake Tekapo and Lake Pukaki are both utilized for hydropower. Hooker Glacier, Mueller, Murchison and Tasman Glacier drain into Lake Pukaki, where water level has been raised 9 m for hydropower purposes. Water from Lake Pukaki is sent through a canal into the Lake Ohau watershed and then through six hydropower plants of the Waitaki hydro scheme: Ohau A, B and C. Benmore, Aviemore and Waitaki with a combined output of 1340 MW. Meridian owns and operates all six hydro stations located from Lake Pūkaki to Waitaki. The reduction of glacier area in the region will reduce summer runoff into Lake Pukaki and this hydropower system.

Gunn Glacier in, 2006 above and 2012 below,Google Earth image. Red arrows the 2006 terminus position yellow arrows 2012 terminus location. The glacier lost 25% of its area in six years.

Individual Glacier Posts

Murchison Glacier Tasman Glacier Balfour Glacier

Mueller Glacier Hooker Glacier Salisbury Snowfield

Lyell Glacier Douglas Neve Gunn Glacier

Upper Volta Glacier Donne Glacier

Donne Glacier from 2003-2012 in Google Earth images. Red arrow is the 2003 terminus and yellow arrow the 2012 terminus. A seven hundred meter retreat in a decade.

Alpine Glacier Mass Balance in 2015: Competes for Record Loss

On March 17, 2016May 2, 2024 By mspeltoIn climate change glacier retreat, glacier climate change, Glacier Observations1 Comment

Painting from Jill Pelto illustrating the Climate Change Data using multiple quantities: the annual decrease in global glacier mass balance, global sea level rise, and global temperature increase. The numbers on the left y-axis depict quantities of glacial melt and sea level rise, and the suns across the horizon contain numbers that represent the global increase in temperature, coinciding with the timeline on the lower x-axis.

The World Glacier Monitoring Service (WGMS) record of mass balance and terminus behavior provides a global index for alpine glacier behavior. The WGMS data set for terminus change contains 42 000 observations from 2000 glaciers extending from the mid-19th century. Annual mass balance is the annual change in volume due to snow and ice accumulation and snow and ice losses. Here, mass balance is reported in mm of water equivalent. The following analysis is something I work on annually as the United States Representative to the WGMS, putting the alpine glacier mass balance of the globe in perspective. Preliminary data for 2015 from 16 nations with more than one reporting glacier from Argentina, Austria, Canada, Chile, Italy, Kyrgyzstan, Norway, Switzerland, and United States indicate that 2015 will be the 36^th consecutive year of negative annual balances with a mean loss of −-1162 mm for 27 reporting reference glaciers and −1481 mm for 62 of all reporting glaciers (WGMS 2016). The number of reporting reference glaciers is 90% of the total whereas only 50% of all glaciers that will report have reported to date. When all data are available the 2015 mass balance will likely be comparable to 2003 the most negative year at −1268 mm for reference glaciers and −1198 mm for all glaciers.

The cumulative mass balance loss from 1980–2015 is 18.8 m, the equivalent of cutting a 20.5 m thick slice off the top of the average glacier. The trend is remarkably consistent from region to region (WGMS 2015). The decadal mean annual mass balance was −261 mm in the 1980s, −386 mm in the 1990s, -−727 mm for 2000s and −818 mm from 2010–15. The declining mass balance trend during a period of retreat indicates alpine glaciers are not approaching equilibrium and retreat will continue to be the dominant terminus response (Zemp et al. 2015). The recent rapid retreat and prolonged negative balances has led to many glaciers disappearing and others fragmenting (Pelto 2010; Carturan et al. 2013).

Annual glacier mass balance record of reference glaciers reporting to the WGMS.

In South America seven glaciers in Columbia, Argentina, and Chile reported mass balance. All seven glaciers had losses greater than −1200 mm, with a mean of −2200 mm. These Andean glaciers span 58°of latitude.

In the European Alps, mass balance has been reported for 14 glaciers from Austria, France, Italy, Spain and Switzerland. All 15 had negative balances exceeding −1000 mm, with a mean of −1860 mm. This is an exceptionally negative mass balance rivaling 2003 when average losses exceeded −2000 mm.

In Norway mass balance was reported for seven glaciers in 2015, all seven were positive with a mean of 860 mm. This is the only region that had a positive balance for the year. In Svalbard six glaciers reported mass balances, with all six having a negative mass balance averaging −675 mm.

In North America Alberta, British Columbia, Washington, and Alaska mass balance data from 17 glaciers was reported with a mean loss of −2590 mm, with all 17 being negative. This is the largest negative mass balance for the region during the period of record. From Alaska south through British Columbia to Washington the accumulation season temperature was exceptional with the mean for November–April being the highest observed.

In the high mountains of central Asia seven glaciers from China, Russia, Kazakhstan, and Kyrgyzstan reported data, all were negative with a mean of –705 mm.

Columbia Glacier, Washington in 2015 during our mass balance observations from the terminus and head of the glacier indicating the lack of snow cover retained and extensive melting,

Lago Onelli, Argentina trio of Glaciers Retreat and Separate

On March 10, 2016May 2, 2024 By mspeltoIn argentina glacier retreat, glacier climate change, Glacier Observations

Onelli Glacier (O), Belados Glacier (B) and Agassiz Glacier (A) compared in Landsat images from 1985 to 2016. The red arrow indicates the 1985 terminus location and yellow arrow is the 2016 terminus location.

The Onelli Glacier drains eastward from the South Patagonia Icefield (SPI) into Lago Onelli (LO), which then connects to Lago Argentino. Lago Onelli has three main glaciers terminating in the lake Agassiz (A), Onelli(O) and Bolados Glacier (B). Onelli glacier is noted as 13 km long with an area of 84 square kilometers by the Labratorio de Glaciologia in Chile . Davies et al (2012) noted that the most rapid period of retreat since 1890 for Bolado and Onelli Glacier was from 1986-2001. Warren and Sugden (1993) note an 1800 meter retreat from 1945-1992 for Onelli Glacier and 850 meters for Agassiz Glacier. Eric Shipton was the first to visit this glacier and did so in the company of Ohio State glaciologist John Mercer in 1958. They found Lago Onelli so filled with icebergs that little water could be seen (Shipton, Land of Tempest, 1963). Agassiz and Onelli Glacier were observed to have a shared terminus in 1958 much like Onelli Glacier and Belados Glacier in 1985.

A comparison of Landsat satellite images indicate the separation and retreat of Bolados (B) and Onelli Glacier (O) from 1985-2016. In 1985 the joint terminus cuts directly across Lago Onelli as one reasonably straight 1.6 km wide calving front just short of connecting with Agassiz Glacier. By 2004 the glacier had retreated 3000 m and Belados and Onelli were barely touching.The combined termini width was 1.8 km. By 2010 the glaciers were separated by 1300 meters. By 2016 Belados Glacier has retreated 3500 m from 1985-2016 and Onelli Glacier has retreated 3800 m. The glaciers in 2016 are separated from each other by 1800 m. The ELA in the satellite images from recent years has been 1300 meters. Agassiz Glacier has retreated 400 m during the 1985-2016 period. The glacier is grounded on three islands that acts as pinning points, reducing calving losses and the retreat rate.

Willis et al (2012) examined the mass change of the 12,100 km² SPI from 2000-2012: in the accumulation zone the average thickness change of −1.1 ± 0.1 m/year, for the ablation zone the average thickness change is −3.5 ± 0.02 m/year. This widespread loss even in the accumulation zone indicates that retreat will continue. A comparison of Landsat images from 1998 to 2013 indicates upglacier thinning at the purple arrows. Schaefer et al (2015) noted that the mass loss of SPI has been largely from increased calving losses. Mouginot and Rignot (2015) observed that Onelli Glacier does not have a high velocity reach extending beyond the immediate terminus zone, unlike major outlet glaciers of the SPI.