Glacier Blanc on Ecrins Retreat, France

On January 6, 2013January 6, 2013 By mspeltoIn Glacier Observations2 Comments

Glacier Blanc is on the east side of Barre Des Ecrins the southernmost of the 4000 m peaks in the Alps. It is the largest glacier on the peak. The glacier began a sustained retreat after 1870, that ceased in 1895-1900 , 1915-1920, 1935-1940 and 1980-1990 (Cossart et al, 2006). The glacier had a mass loss of 11 m from 1981-2005 (Rabatel et al, 2008), which is 5-10% of the total glacier volume. John Hessler, a physical geographer has an excellent series of images from Glacier Blanc, including the image above of terminus change from the Cossart et al (2006) paper. Glacier Blanc was joined with Glacier Noir in 1900, today Glacier Blanc has retreated 1.5 km from the former connection in the St. Pierre River valley, as seen in the image below from Cossart et al (2006).
The series of images below are used to examine the retreat over the last 27 of Glacier Blanc. The first image is a 2003 Google Earth image illustrating the 1985 terminus a pink line, 2003 a purple line and 2010 a red line. The images following are a 1985 Landsat image, pink arrow terminus and blue arrow snowline. The closeup of the terminus in 2003 and 2010 indicates the change in terminus position and stagnant ice. The last image from 2012 notes the 1985 terminus position with pink arrow and the snowline blue arrow. Retreat from 1985 to 2003 was 320 meters, 18 meters/year. From 2003 to 2010 retreat is 250 meters, 36 meters/year. The rate of retreat is increasing. This glacier largest area is the valley basin from 3000 to 3300 meters which is 2.7 km long and 0.9 km long. For the glacier to babove 3200 meters from 2002-2005 (Rabatel et al, 2008). This basin certainly is over deepened and would have a lake if the terminus retreats into it significantly. The glaciers retreat has been similar to that of Glacier de la Girose just 15 km north.

Glacier de la Girose Retreat, France

On January 3, 2013January 6, 2013 By mspeltoIn france glacier retreat, Glacier Observations1 Comment

Glacier de la Grirose (Girose) is one of the most travelled glaciers in the Alps. It is part of the Les 2 Alpes ski resort, used primarily for summer skiing. The main glacier serviced by a lift is Glacier Mantel just to the west of Girose. Despite the frequent visits to the glacier by skiers it has not been the focus of much study. The glacier is smaller than often visited but seldom skied Mer De Glace, similar to Glacier Blanc 15 km south and larger than the Grande Motte at Tignes ski area. Here we examine changes from 1984-2012 using Landsat images, Google Earth images and two photographs. Girose has three termini from west to east labelled A-C. The 1985 terminus location is marked by red arrows, the 2003 terminus is indicated by a purple line, the 2009 terminus by an orange line adn the lip of a key icefall here the middle branch (B) separates from the main branch (C). In 1985 this icefall lip is 500 m above the terminus. The two western termini A and B both extend well below the main icefield of Girose in 1985, by 2012 the tongues barely extend beyond the main glacier. The views of the terminus are in order a 1984 photograph, a 1985 Landsat, 2003 Google Earth, 2010 Google Earth and 2012 Landsat image. They are all viewed from the north. Retreat from 1985 to 2010 has been 420 m at terminus a, 500 m at terminus B and 350 m at terminus C. The overall rate is 15 meters/ year.

Of greater concern is the expansion of outcrops amidst the accumulation zone of the glacier from 2003 to 2010. This indicates thinning in the accumulation zone, which indicates the lack of a persistent snowcover even for many regions high on the glacier. The two images below identify three locations, at A and B the expansion of bedrock is evident. The scale is the same, at point A the rock outcrop is no longer a narrow linear feature. At Point B the rock outcrop is much longer. At point C there is a sharp reduction in crevassing, and the glacier surface is quite dark colored, this is not a rock amidst the glacier, instead the dark area indicates a portion of the glacier surface that has persistently lost its snowcover and where dirt at the surface has been preferentially enriched. This helps speed thinning, but in the former accumulation zone is a sign it is no longer an accumulation zone. The ski season is supposed to extend from mid- June to Sept. 1 for Les 2 Alpes on the glaciers, in many recent years the season is cut short on Girose.

Snowcap Creek Glacier Retreat, British Columbia

On December 31, 2012December 31, 2012 By mspeltoIn Glacier Observations

Snowcap Creek Glacier is one valley north of Stave Glacier in the Garibaldi Provincial Park Region of British Columbia. The retreat of glaciers in this region has been well documented by Koch et al (2009). The response varies from a glacier like the Helm Glacier which is melting away to the Snowcap Creek Glacier which is has been rapidly retreating but has remained vigorous.

Landsat images and Google Earth images are used to document the development of a lake at the terminus of the glacier. In 1992 there is no lake at the main terminus, red arrow or subsidiary terminus at the yellow arrow. There is also a connection between the terminus and the glacier to the north at the magenta arrow. By 2009 there is a new lake at the main terminus that is 700 meters across the glacier reaches the western shore of this lake. A smaller lake has formed at subsidiary terminus, yellow arrow. The terminus is no longer connected to the glacier to the north at the magenta arrow. By 2012 the glacier has retreated 800 meters from 1992 and no longer reaches the western margin of the new unnamed lake, red arrow. The subsidiary terminus lake has expanded but is still less than 100 meters across.

In each image the snowline is noted by a yellow-orange arrow, the glacier continues to have a persistent accumulation, which indicates it can survive current climate. A closer examination of the terminus in 2006 from Google Earth indicates the two new lakes, the detached ice remnant and active crevassing of the glacier surface close to the terminus. In 2006 the glacier terminus still reaches the newly formed lake. The active crevassing begins within 300 meters of the current terminus. The ice tongue reaching down to the lake has already retreated from it and this narrow tongue will be lost soon.

Roosevelt Glacier Retreat, Mount Baker, Washington

On December 27, 2012December 27, 2012 By mspeltoIn Glacier Observations1 Comment

Roosevelt Glacier is on the northwest side of Mount Baker, Washington with its accumulation zone joined with the Coleman Glacier. My first visit to Roosevelt Glacier was in 1984, when the glacier had just completed a 30 year period of advance from 1949-1979. Since 1979 the glacier has been retreating, image below. This post examines Google Earth imagery from 1993, 2003 and 2009 along with field observations from the glacier. The purple line indicates the advance moraine that the glacier emplaced during the 1949-1979 period of advance. We mapped the location of this moraine in 1985, when it was still recent and very evident. The red line is from 1993, yellow line from 2003 and green line from 2009. In 1993 the area below the lip of lava flow cliff is thin and stagnant, cliff noted by purple arrow. By 2003 the glacier has retreated to the top of the cliff and by 2009 the glacier has pulled back from the edge of the cliff. By 2012 the lower glacier, viewed from the edge of the Coleman Glacier, is thin and uncrevassed in the lower 350 meters of the glacier, up to the red arrow. The glacier retreated 190 meters from 1979 to 1993 and 220 meters from 1993 to 2009. The rate of 14 m/year has been relatively consistent.

The glacier is fed by three principal accumulation zones: 1) A glacier tongue that descends from the summit plateau at 3200 meters, 2) an avalanche fed and direct snowfall region beneath the north ridge, at 2200 meters 3) an avalanche and direct snowfall fed region beneath the northwest face, at 2400 meters. The annual snowline has averaged 2150 meters on Roosevelt Glacier from 1984-2010, which has led to a similar retreat of 14 m/year and mass balance loss -0.52 m/year of all Mount Baker glaciers, Pelto and Brown (2012). Each summer we investigate the retained snow depth retained in the crevasse stratified exposures on Mount Baker in the 2400 meter range. Below are several images from this investigation. In the second image the magenta arrows indicate specific annual layers that have been retained. Typical thicknesses are 1.75 to 2.25 m. The next two images are from when we are in an icefall looking for the best exposure to measure the annual layer stratigraphic thickness. The behavior of this glacier parallels that of Deming Glacier, Boulder Glacier and Rainbow Glacier all on Mount Baker.

December 2012 Glacier Post Index

On December 24, 2012 By mspeltoIn Glacier Observations4 Comments

Below is a list of the individual glacier posts examining our warming climates impact on each glacier. This represents the first 3.4 years of posts, 262 total posts, 240 different glaciers. I have worked directly on 46. The others are prompted by fine research that I had come across, cited in each post or inquiries from readers and other scientists. I then look at additional often more recent imagery to expand on that research. The imagery comes either from MODIS, Landsat, Geoeye or Google Earth. There is a consistent signal from the glaciers, mass balance loss, thinning and retreat. In many cases this leads to new lake formation or lake expansion for alpine glaciers. I will continue to record these changes here with a new post twice a week and in the field.

Himalaya
Ngozumpa Glacier, Nepal
West Barun Glacier, Nepal
Khumbu Glacier, Nepal
Imja Glacier, Nepal
Reqiang Glacier Retreat, Nepal
Kali Gandaki Headwaters, Nepal
Samudra Tupa, India
Malana Glacier, India
Sara Umaga Glacier, India
Zemu Glacier, Sikkim
North Lhonak Glacier, Sikkim
Changsang Glacier, Sikkim
Gangotri Glacier, India
Milam Glacier, India
Satopanth Glacier, India
Theri Kang Glacier, Bhutan
Zemestan Glacier, Afghanistan
Emend River Headwaters, Afghanistan
Yajun Peak Glacier, Afghanistan
Godur Glaicer, Pakistan
Tirich Mir, Pakistan
Longbasba Glacier, Tibet
Menlung Glacier, Tibet
Boshula Glaciers, Tibet
Urumquihe Glacier, Tibet
Lumding Glacier, Tibet
Matsang Tsanpo Glacier, Tibet
Dzhungharia Alatau, Kazakhstan
Petrov Glacier,Kyrgyzstan
Hailuogou Glacier, China
Himalaya Glacier Index

Europe
Taconnaz GLacier, France
Mer de Glace, France
Dargentiere Glacier, France
Grand Motte and Pramort Glacier Tignes Ski area, France
Saint Sorlin, France
Sommelier Glacier, France
Obeeraar Glacier, Austria
Rotmoosferner, Austria
Stubai Glacier, Austria
Hallstatter Glacier, Austria
Ochsentaler Glacier, Austria
Pitzal Glacier, Austria
Dosde Glacier, Italy
Presena Glacier, Italy
Forni Glacier, Italy
Careser Glacier, Italy
Lobbia Glacier, Italy
Sabbione Glacier Retreat, Italy
Triftgletscher, Switzerland
Gietro Glacier, Switzerland
Ried Glacier, Switzerland
Cavagnoli Glacier, Switzerland
Chuebodengletscher and Ghiacciaio-del-Pizzo-Rotondo, Switzerland
Peridido Glacier, Spain
Maladeta Glacier, Spain
Engabreen, Norway
Midtdalsbreen, Norway
Tunsbergdalsbreen, Norway
Lodalsbreen, Norway
Rembesdalsskaka, Norway
TungnaarJokull, Iceland
Langjökull, Iceland
Gigjokull, Iceland
Porisjokull, Iceland
Skeidararjokull, Iceland
Kotlujokull, Iceland
Lednik Fytnargin, Russia
Kirtisho Glacier, Georgia
Lednik Kauraugom, Russia
Irik Glacier, Mount Elbrus, Russia

Greenland and European Arctic
Mittivakkat Glacier
Ryder Glacier
Humboldt Glacier
Petermann Glacier
Kuussuup Sermia
Thrym Glacier Retreat
Tiningnilik Glacier Lake
Jakobshavn Isbrae
Zachariae Isstrom
Umiamako Glacier
Alison Gletscher
Kong Oscar Glacier
De Reste Bugt
Qaleraliq Glacier
Upernavik Glacier
Apuserajik Glacier
Epiq Sermia
Sarqardliup Seremia
Steensby Glacier
Sortebrae Glacier, Greenland
Severnaya Zemlya, Russian Arctic
Hansbreen, Svalbard
Nannbreen, Svalbard
Hornbreen and Hambergbreen, Svalbard
Olsokbreen, Svalbard
Albrechtbreen, Svalbard
Roze and Sredniy Glacier, Novaya Zemyla
Nizkiy and Glazova Glacier, Novaya Zemyla

South America
Colonia Glacier, Chile
Artesonraju Glacier, Peru
Nef Glacier, Chile
Tyndall Glacier, Chile
Alemania Glacier, Chile
Zongo Glacier, Bolivia
Sierra Nevade del Cocuy Glaciers, Colombia
Ritacuba Blanco Glacier, Colombia
Llaca Glacier, Peru
Joerg Montt Glacier, Chile
Nororeste Glacier, Chile
Arhuey Glacier, Peru
Seco Glacier, Argentina
Onelli Glacier, Argentina
Quelccaya Ice Cap, Peru
Manon Glacier, Peru
Chuecon Glacier
Glacier Gualas, Chile

Antarctica and Circum Antarctic Islands
Pine Island Glacier
Fleming Glacier
Hariot Glacier
Smith Glacier, Antarctica
Thwaites Glacier, Antarctica
Amsler Island
Stephenson Glacier, Heard Island
Neumayer, South Georgia
Ampere, Kerguelen
Lapparent Outlet, Kerguelen Island
Cook Ice Cap, Kerguelen Island
Nordenskjold Coast, Antarctic Peninsula
Prospect Glacier, Antarctic Peninsula
Ross Hindle Glacier, South Georgia
Vega Island Ice Cap
Rohss Bay, James Ross Island, Antarctica
Jones Ice Shelf, Antarctica

New Zealand
Tasman Glacier
Murchison Glacier
Donne Glacier
Mueller Glacier, NZ
Gunn Glacier, NZ
Douglas Glacier Neve, NZ

Africa
Rwenzori Glaciers
Tyndall Glacier, Kenya

North Cascade Glacier Climate Project Reports

Forecasting Glacier Survival
North Cascade Glacier Mass Balance 2010
Columbia Glacier Annual Time Lapse
North Cascade Glacier Climate Project 2009 field season
28th Field Season Schedule of the North Cascade Glacier Climate Project
North Cascade Glacier Climate Project 2011 Field Season
BAMS 2010 alpine glaciers
BAMS 2011 Alpine Glaciers
2011 Glacier mass balance North Cascades and Juneau Icefield
Taku Glacier TSL Paper
Glacier Ground Truth 2012 North Cascade Field Season
North Cascade Glacier Climate Project 2012 Field Season

Changsang Glacier Retreat and Lake Formation, Sikkim

On December 22, 2012February 8, 2013 By mspeltoIn Glacier Observations3 Comments

Changsang Glacier is a valley glacier just north of Kanchengjunga, the third highest peak, in Sikkim. A comparison of Landsat imagery from 1989 to 2012 identifies the formation of a lake at the end of the glacier. The red arrow indicates the downvalley end of the lake that will develop, the green arrow the upvalley end. In 1989 there is no evidence of a lake either on top of the glacier, supraglacial or proglacial, at the end of the glacier. In 2000 there are a several small lakes beginning to develop. In the 2006 Google Earth imagery the lake is 700 meters long with several other developing smaller lakes. By 2011 the main lake is 1000 meters long and has one debris covered ridge that separates it from a second lake. By 2012 the lake has expanded incorporated the second lake and is now 1500 meters long. The Changsang Glacier was reported to be retreating 22 m/year from 1976 to 2005 (Raina, 2009). In Sikkim 26 glaciers examined were retreating at an average rate of 13.02 m per year from 1976 to 2005 (Raina, 2009) is following the same path as South Lhonak Glacier just to the north and Zemu Glacier just to the south. Zemu Glacier to the south is fed by a higher accumulation zone, and has not been retreating as fast, but it should be anticipated that a lake will form near its terminus.

A closeup view of the terminus area in 2006 indicates the main lake and several smaller lakes that will join the main lake by 2012. The purple arrow indicates the outlet river from beneath stagnant debris covered ice. The orange arrows indicate the extent of the developing lake by 2012.

Kirtisho Glacier Retreat, Georgia

On December 17, 2012December 17, 2012 By mspeltoIn Glacier Observations

The southern flank of the Caucasus Mountains is in the nation of Georgia. Ten kilometers southwest of the Lednik Karaugom Glacier, Russia from the previous post is Kirtisho Glacier a 4.5 km long valley glacier, a small subglacier KS is also examined in this post. The glaciers in the Causcasus Mountains have been undergoing a significant retreat, the USGS, (2010) Satellite Image Atlas of Asia, noted that nearly all of the 65 glaciers examined in this region experienced significant retreat from 1987-2004. Shahgedanova et al, (2009) noted a 8 meters per year average retreat rate for the 1985-2000 period. To get a feel for the terrain watch the trailer for the On the Trails of the Glaciers- Caucasus 2011. The video does not show Kirtisho Glacier but does indicate the nature of the terrain. This is a project of an Italian group Macromicro, that had contacted me about an upcoming expedition to Alaska in 2013. Landsat images from 1986 (second image) and 2012 (third image) along with 2011 Google Earth imagery (top and bottom image) are shown below. Kirtisho Glacier has a top elevation of 3700 meters and a terminus that in 2012 is at 2600 meters, and was 2400 m in 1986. The snowline has typically been at 3300 meters, blue arrow, which is too high to sustain the terminus at 2600 m. The terminus position in 1986 is indicated by a red and yellow arrow that are also used in the 2012 imagery and the 2011 terminus closeup. The magenta arrow in the Landsat images indicates the beginning of a separation from an northern tributary, which is close to the snowline. The terminus itself is not crevassed in the lowest 400 meters, suggesting retreat will continue for this nearly stagnant section. KS the small glacier to the south, has decreased in area from 0.45 km2 in 1986 to 0.20 km2 in 2012. We also examine this more below.

The KS glacier viewed up close is quite thin, with limited crevasses. The red arrows indicate rock protruding through this glacier in many locations. These rocks indicate how thin the ice is, and will help absorb heat and hasten melting as the rock outcrops expand. In 2011 and in the 2012 imagery there is no remaining snow on the glacier. A glacier without a persistent accumulation zone cannot survive (Pelto, 2010). KS glacier will not survive much longer.

Lednik Karaugom Glacier Retreat Caucasus Mountains, Russia

On December 14, 2012February 22, 2014 By mspeltoIn Glacier Observations1 Comment

Lednik Karaugom Glacier is a large 13 km long, valley glacier in the Caucasus Mountains of Northern Ossetia, Russia. The glacier drains into the Urukh River which joins the Terek River and then flows into the Caspian Sea. This post compares Landsat imagery from 1986, 2010 and 2012, an image from the USGS in 2002 and Google Earth imagery from 2009. This glacier has experienced a general retreat like all the glacier draining north from the Caucasus Mountains. USGS, (2010) Satellite Image Atlas of Asia, noted that nearly all of the 65 glaciers examined in this region experienced significant retreat from 1987-2004, noting a retreat of Karaugom of 600 m. Maria Shahgedanova, has an ongoing project examining Caucasus glaciers. Shahgedanova et al, (2009) noted a 8 meters per year average retreat rate for the 1985-2000 period. The glacier retreat has led to an increase in debris cover and an increase in the number of proglacial and supraglacial lakes. (Stokes et al , 2007) This glacier begins at the Russia-Georgia border and extends up to the base of Gora Uilpata at 4200 meters. There is a substantial icefall separating the accumulation zone above 3500 meters from the ablation zone of the valley tongue beginning at 2500 m.from 1987-2002. In the series of images below the yellow arrow indicates the 1986 terminus position, the pink arrow the 2012 terminus position, the orange arrow the 2002 terminus position and the blue arrow the former connection with a tributary. The retreat from 1986 to 2012 is 1300 meters, about 50 meters/year. The retreat of the tributary from the main glacier has been 200 meters, or 8 meters/year.

A closeup of the terminus indicates the amount of debris cover, and the formation of ogives at the base of the icefall. The lateral moraine marking the previous ice surface elevation is also noted with a green arrow. This glacier remains vigorous in its flow, with substantial crevassing and ongoing crevasse formation. The retreat is ongoing but the end of the glacier is not stagnant, though the lower 300 meters has reduced crevassing and width. The degree of crevassing at the green arrows at a small icefall 300 meters above the terminus indicates both ice thickness and flow and suggest that the retreat will likely be reduced in the near future. The behavior is similar to that of Lednik Fytnargin and Irik Glacier on Mount Elbrus

Stave Glacier Retreat, British Columbia

On December 10, 2012December 10, 2012 By mspeltoIn Glacier Observations1 Comment

Stave Glacier is a six kilometer long valley glacier in Garibaldi Provinical Park, British Columbia. Koch et al (2009) in their detailed survey of glaciers in the park chronicled the glacier’s retreat from 1952 to 1996. Here we update the changes in Stave Glacier to 2012. Koch et al (2009) completed a map, first image that indicates the retreat rate of the glacier as 26 meters/year from 1900-1952, 33 meters/year 1952-1977 and 53 meters/year from 1977 to 1996. Examined below is Google Earth imagery from 2006, aerial photography from 2009 and Landsat imagery from 2009 and 2012. The Google Earth image indicates the terminus position using arrows in 1952 (yellow arrow), 1977 (pink arrow), 1996 (orange arrow), 2006 (blue arrow) and 2012 (purple arrow). In the Landsat images the same color scheme is used, for terminus front lines also. The retreat from 1996-2012 is 1600 meters, 100 meters/year. This glacier is still not approaching equilibrium as the accelerating retreat indicates.

A close up of the terminus in 2006 (top) and 2009 (bottom) indicates the lowest couple hundred meters is thin and uncrevassed indicating retreat will continue. The glacier terminus is at 1275 meters today. There is an active icefall above the terminus at 1500 meters, the snowline has been at 1900 meters. Unlike the nearby Helm Glacier, Stave Glacier has a persistent accumulation zone and can survive current climate. Its behavior is similar to that of Warren Glacier.

Qaleraliq Glacier Retreat, Southern Greenland

On December 6, 2012April 3, 2014 By mspeltoIn Glacier Observations3 Comments

Qaleraliq Glacier is in southern Greenland and flows into the Tasermiut Fjord. Glaciers in this region have experienced substantial retreat since 1990 Weidick et al (2012) and Howat and Eddy (2011). Howat and Eddy (2011) state that, “We find that 90% of the observed glaciers retreated between 2000 and 2010, with rapid retreat observed in all sectors of the ice sheet. The current retreat is accelerating and likely began between 1992 and 2000, coincident with the onset of warming, following glacier stability and minor advance during a mid-century cooling period.” In this case we are examining a tidewater glacier in Southern Greenland using satellite imagery from 1992, 2004, 2010 and 2012. In each image locations A-D are in the same locations marking specific bedrock islands (nunataks) within the ice sheet. The yellows arrows indicate the 1992 terminus position in each image, the black arrow denotes the terrain south of bedrock nunatak B. Retreat of the west arm of the glacier has been 3.2 km from 1992 to 2012. The east arm retreat in the last twenty years has been 1.2 km. In 1992 Nunatak A is 1.5 km from the ice edge and is composed of two separate nunataks. By 2010 the two nunataks have merged and by 2012 Nunatak A is 1 kilometer from the ice edge. In 1992 Nunatak B is 3 km from the icefront surrounded by the ice sheet and in 2012 the nunatak has increased in size and extends 1 km beyond the terminus. Nunatak C has largely emerged from the ice sheet, the nunatak has also expanded in length by 500 meters as ice has thinned during the retreat. The Nunatak at D did not exist in 1992, but by 2012 it is over 1 km long.

A close up view of the terminus and Nunatak B and C from 1992 and 2012 illustrates the expansion of the nunataks as ice has thinned. The locations at the green and purple arrows are the same in both images. In 1992 these locations are near the nunatak margin and by 2012 the locations are in the midst of the Nunatak. Qaleraliq Glacier behavior is similar to that of almost all southern Greenland glaciers, most of which like Qaleraliq have not been the focus of detailed study, such as Kuussuup Sermia, Narssap Sermia or Kangiata Sermia. In the Tasermiut Fjord Biggs (2011) noted the retreat of two glaciers Sermitsiaq and Itillersuaq that have each retreated 600 and 300 m respectively from 1987 to 2009.The unusual nature of the 2012 melt season can be seen in this animated graph of ice sheet melt extent with data from Marco Tedesco, Figure 2a in the recent paper submitted (Tedesco et al, 2012).

Fork Glacier Retreat and Separation, Brooks Range, Alaska

On December 3, 2012December 3, 2012 By mspeltoIn Glacier Observations

The Romanzof Mountains in the Brooks Range of Alaska has numerous small alpine glaciers. This is an area that has seen some of the greatest warming of anywhere over the last 30 years. In this post we focus on Fork Glacier which is just northwest of Okpilak Glacier. The glaciers in this region have been undergoing significant thinning and mass loss (Delcourt et al, 2008) including on McCall Glacier, Okpilak Glacier and Romanzof Glacier. Here we examine the changes in Fork Glacier, that has an 2.5 km long east and 3.5 km long west arm that joined at 1800 meters. The glacier than descends 600 meters to a terminus at 1700 m in 1982, the western arm is longer, wider and begins higher at 2300 meters. The first image is a 1982 aerial photograph from the USGS, followed by a 2000 Landsat image, 2009 Google Earth and 2012 Landsat image. The Pink A indicates where the two arms of the glacier joined, the pink arrows indicate the 1982 terminus and the yellow arrow the 2009 terminus. The glacier remained joined in 2000, but for a shorter distance than in 1982. By 2009 the glacier had retreated 400 meters from 1982 and has separated at the terminus. By 2012 the eastern terminus has separated by 200 m from the west branch, green arrow. The other problem evident in the 2012 satellite imagery is the limited extent of snowpack on the glacier at the purple arrows. This level of snowpack even with a month left in the accumulation season indicates a glacier without a consistent accumulation zone that cannot survive (Pelto, 2010) A close up view of the terminus from the 2009 Google Earth imagery indicates the retreat but also the green arrow highlights a supraglacial stream that indicates stagnant ice on the eastern arm of the glacier.

Jones Ice Shelf Loss, Antarctica

On December 1, 2012December 1, 2012 By mspeltoIn Glacier Observations

The Jones Ice Shelf was midway up the west coast of the Antarctic Peninsula. The ice shelf (red arrow) was smaller than other ice shelves that have mostly or substantially disintegrated Wordie Ice Shelf (orange arrow), Larsen B Ice Shelf (pink arrow) or Wilkins Ice Shelf (green arrow). The British Antarctic Survey (BAS), has been observing the changes in ice shelves around the Peninsula Cook and Vaughan, (2010) and Fox and Vaughan (2005). The BAS noted that the ice shelf had an area of 29 square kilometers in 1980, by 1990 21 square kilometers and 10 square kilometers in 2000 and 2003, gone. Blaicklock Island (C and D) and the Arrowsmith Peninsula (A and B) are now separated by open water in Jones Channel. Cook and Vaughan (2010) also note that this was not the result of a long ongoing retreat, the Jones Ice Shelf expanded 20 % between 1947 and 1978. In the post below there is a sequence of images from Landsat and Google Earth imagery in a sequence as follows, 1989, 1991, 1999, 2009 and 2011. The Ice shelf exists in 1989 and 1991, ending at the orange arrows, which are included in the 2009 and 2011 images as well for comparison. Points A-D are in the same location in each image. The 1999 image indicates a disintegrating Jones Ice Shelf (JIS), with a small ice tongue protruding part way across Jones Sound, the new waterway that has opened. By 2009 the glacier has retreated out of the Jones Channel to the pink arrow and red line in 2011. The eastern terminus retreated 4 km and the western terminus 7 km. The ice shelf loss here is similar in magnitude to Rohss Bay on James Ross Island.