Nizina Glacier Retreat, Lake Formation, Alaska

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

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

Google Earth image

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

1990 Landsat image

1995 Landsat image

1999 Landsat image

2013 Landsat image

2014 Landsat image

Google Earth image 2012

Roncagli Glacier Retreat, Tierra del Fuego, Chile

On December 29, 2014December 29, 2014 By mspeltoIn Glacier Observations1 Comment

The Cordillera Darwin in Tierra Del Fuego, Chile is a remote area that is notorious for stormy, cloudy weather that makes for only a few good satellite images. Roncagli(Alemania) Glacier is the focus of this post and is an update to a previous post. The glacier has a terminus adjacent to the Beagle Channe(BC) and a secondary terminus in Lago Martinic (LM), 5 km upglacier. Velocity profiles by Melkonian et al (2013) indicate the highest velocities directed toward the LM terminus, making this the primary terminus. They also found that the glacier thinned by 5-10 m along most of its length from 2000-2011. Here we examine Landsat imagery from 1997 to 2014.

Googel Earth image
In 1997 the BC terminus at the pink arrow is at a narrowing of the valley. The LM terminus is at the yellow arrow with two primary glacier branches encircling the nunatak at the red arrow. In 2000 the terminus positions are relatively unchanged with the LM terminus actively releasing icebergs into Lago Martinic. Upglacier a single area of bedrock is emergent through the glacier, purple arrow. In 2001 the BC terminus remains unchanged, the water level in LM has declined exposing more bare rock surfaces around the LM terminus. By 2008 the LM terminus has separated, both still ending in the lake, the lake again is at a full stage on the date of the imagery. The lake experienced periodic filling and draining episodes during the 1997-2008 period. There are now two upglacier areas with exposed bedrock now. By 2014 the BC terminus has retreated 1 km along the southeastern margin and 200 m along the northwest side. This retreat from the pinning point that restricted calving at the pink arrow, suggests further retreat will occur in the near future. Lago Martinic has largely drained. The LM terminus has separated into two tongues and the former nunatak is no longer surrounded by glacier ice, red arrow. The retreat at LM terminus is 1500 m on the west side, orange arrow, and 800-1000 m on the east side. Upglacier both areas of bedrock that are emergent are expanding, purple arrows, indicating the thinning observed by Melkonian et al. (2013). The continued upglacier thinning indicates reduced flux to the terminus and continued retreat. The degree to which Lago Martinic can refill is uncertain, MODIS imagery from late 2014 shows the lake is still not filled. I have not seen imagery indicating even a nearly full lake in the 2011-2014 period. The rate of retreat is less than on Marinelli Glacier to the north or Glaciar Steffen.

1997 Landsat image

2000 Landsat image

2001 Landsat image

2008 Landsat image

2014 Landsat image

Marinelli Glacier Retreat, Chile

On December 23, 2014 By mspeltoIn Glacier Observations

Marinelli Glacier, Chile is the largest glacier of the Cordillera Darwin Icefield. This ice cap is in Tierra del Fuego, a region famous for cloudy, stormy weather. Fernandez et al. (2011) indicate that rapid retreat particularly since 1945 has led to high erosion and sedimentation rates. They also provide an excellent diagram of the glacier from three time periods. The glacier extended to the Little Ice Age-Neoglacial moraine at the red arrow. Koppes et al (2009) indicate a retreat of 13 km from 1960 to 2005, 300 m/year.

Marinelli Glacier in Google Earth

Cross section of glacier from Fernandez et al (2011)
Melkonian et al (2013) note widespread thinning with a peak on Marinelli Glacier. They also note frontal velocities of 7.5 m/day to 10.5 m/day from 2000 to 2011. They note approximately a 4 km retreat during this period and an average accumulation area ratio (AAR) of 38 (Melkonian et al, 2013). A non-calving glacier needs an AAR over 50 and typically over 60, since calving is an additional loss, calving glaciers typically need an AAR above 70 (Pelto, 1987).

Change in thickness on Marinelli Glacier from Melkonian et al. (2013)

Here we examine Landsat imagery from 1998 to 2014. In 1998 Marinelli Glacier had a main calving tidewater terminus and a land based terminus, red arrow. The tidewater terminus extends beyond the land based terminus. The land based terminus is connected to a tributary at the pink arrow. A tributary from the east is connected to the main glacier at the purple arrow. The yellow arrow is the 2014 terminus position. By 2001 the tidewater terminus has retreated up fjord of the land terminating terminus. The tributary on the west is still connected with the land terminating section of the glacier. By 2008 the main terminus has retreated exposing a new island in the center of the calving front. The land terminating section is now separated from the main glacier and with no supply of new ice will melt away, orange arrow. The tributary from the west is separated from the land terminus now at the pink arrow. The east tributary sill has a connection at the purple arrow to the main glacier. By 2014 the island at the main terminus has expanded in size as the glacier has retreated. The east tributary at purple arrow is separated from the main glacier. The isolated stagnant former land based terminus section between the red and orange arrows continues to melt away. The tidewater terminus of the glacier has retreated about 3.75 km from 1998 to 2014. This is a rate of less than 300 m/year the long term average. The glacier will not stop retreating until its AAR rises and the calving margin reaches a pinning point. In this case there is no lateral pinning point apparent, hence it will have to be a rise in the elevation of the base of the glacier. The velocity and thickness change profile indicate such a location may exist 3-4 km behind the current calving front. This glacier is retreating faster than the other glaciers of this icefield and is more in line with glaciers in the Southern Patagonian Icefield such as, Onelli Glacier, Glaciar Steffen, Glaciar Chico and Jorge Montt Glacier.

Landsat image 1998

Landsat image 2001

Landsat image 2008

Landsat image 2014

Glaciers have the Wrong Business Model

On December 18, 2014January 1, 2015 By mspeltoIn Glacier Observations

This is the story of a glacier that recently went to a bank for a loan, the Sholes Glacier, North Cascade Range, Washington. … “A recent resolution of mine is to work to change my future. I first had to go to the trouble of getting registered as a business so the bank would even recognize my existence, simply having existing on a map was not sufficient. This despite the fact that the water I store and release each summer is valuable to many businesses. I was ushered into the loan office where my basic need was explained, I need to replenish my main asset snow and ice, otherwise the water resource service I provide to others will diminish. The documentation requested included the state of my overall sector. The World Glacier Monitoring Service, collects data on glacier mass balance and terminus change from around the globe, showed that my sector had lost net assets for 25 consecutive years, see below. This graph showed not only that global glacier mass balance has declined 25 years in a row, but that North Cascade glaciers have lost an equivalent amount of volume, the 2014 data is preliminary.

Global Glacier Mass Balance

In fact auditors, glaciologists, have examined my asset sheet each of the last 25 years, and this data was not helpful. I then provided my own net asset sheet indicating a 25% asset loss in the last 20 years. The increased stream of liability from me was eating the long term assets, that were literally no longer frozen. The bank officer, took a hard look and pointed out that, “banks loaned money with the expectation that there would be a return on their investment, improved assets of the loan recipient being crucial”. Given the recent history in the glacier sector I was told, “that our business model was wrong. We cannot expect after 25 consecutive years of loss that a positive asset trend is possible”. I noted that the business model was hard to change and that is was the overall “business” climate that was wrong. This yielded a final rejection, “that maybe true, but until the business climate changes, you still have an unsustainable business model, and any loan would likely simply melt away, so to speak”. So I ask for advice. What can I use for a business model? Will the business climate change in time for my business… How about the other businesses I supply too? I am afraid Kickstarter is not an option. Examine the other glaciers and their stories to see that my story is not unique.

Sholes Glacier, North Cascades of Washington assets melting away.

Snow melt from August 4th to Sept. 12th, 2013 on Sholes Glacier.

Annual balance of glaciers in western North America all losing assets.

East Qorqup Glacier Terminus Disintegration, Greenland

On December 14, 2014 By mspeltoIn Glacier Observations2 Comments

Qorqup Glacier (Qooqqup) is in southern Greenland near Narsarsuaq. The glacier divides shortly above the terminus into an eastern and western glacier branch. Kuussuup Sermia is a distributary glacier of the Qorqup. Here we examine Landsat imagery from 1993 to 2014 and Google Earth imagery from 2005 and 2013. The eastern branch terminus is indicated by the red arrow.
A series of images from 1993 to 2008 indicate limited terminus change, the red arrow indicates the 1993 terminus position on each image. The main change was the minor retreat on the western side of the terminus between 1993 and 1997, where a 600 m wide and 600 m long area was lost. After 2010 the glacier retreated 750 m by 2014. However, in 2014 it is clear that the lower 3 km of the terminus is disintegrating. The disintegration is evident at the pink arrows, with both rifts and iceberg melange sections evident. The Google Earth imagery from 2005 and 2013 indicate a vast change in the character of this terminus reach. In 2005 the terminus is still at the same location, red arrow. The pink arrows indicate crevassing that indicates rapid glacier flow, there is no significant rifting or melange at that time. By 2013 the glacier has retreated from the red arrow at the 1993-2010 terminus position. More importantly each pink arrow indicates an substantial rift or ice melange. The glacier tongue is no longer in contact with the valley walls in its last two kilometers, three kilometers on the east side. There is also a large rift two kilometers from the ice front, indicating a location where the glacier will separate. This rift does penetrate to the water level. The retreat of this glacier is similar to that of Narssap Sermia and Qaleriq Glacier. The rifting leading to calving is what was observed on Petermann Glacier.

1993 Landsat image

1997 Landsat image

2004 Landsat image

2010 Landsat image

2014 Landsat image

2005 Google Earth image

2013 Google Earth image

Davidson Glacier Retreat, Alaska

On December 11, 2014 By mspeltoIn Glacier Observations

Davidson Glacier is a large glacier that flows east from the Chilkat Range to the foreland along Chilkat Inlet and Lynn Canal in southeast Alaska. As a result it has a long history of observation of change. Molnia (2008) noted that from 1889 to 1946 the glacier retreated 400 m and a lake had developed at the terminus. By 1978 the glacier had retreated another 700 m with the proglacial lake at the terminus further expanding. Molnia (2008) futher observed a 700 m retreat by 2004. Here we examine Landsat imagery from 1993 to 2014 to identify recent changes of the glacier.

USGS map

Google Earth Image

In 1984 the glacier terminated at the end of a peninsula extending from the south side of the proglacial lake, red arrow. The purple arrow is the snowline at 1100 m. The orange arrows indicate two tributaries feeding the main glacier. By 2001 the terminus has retreated 500 m into a narrower western section of the lake. In 2004 the snowline is at 1250 m, leaving little accumulation area. In 2009 the snowline is at 1200 m. The terminus has retreated from the proglacial lake. In 2013 the snowline is at 1100 m, there is a river connecting the terminus at the yellow arrow to the proglacial lake. The glacier no longer reaches the foreland having retreated into a mountain valley. In 2014 the snowline was at 1300 m at the start of August with a month left in the melt season. The two tributaries at the orange arrows only have a thin connection to the main glacier. The terminus has retreated 800 meters from 1984 to 2014. The retreat will continue due to the high snowlines in recent years and tributary separation. The retreat is less than most nearby glaciers such as Sinclair Glacier or Ferebee Glacier, just east across Lynn Canal.

Johnson et al (2013) compare changes in Davidson and Casement Glaciers that share a flow divide at 1200 m, Casement Glacier flows west and Davidson Glacier flows east. Both glaciers thinned at a rate of 1 m per year at the flow divide from 1995-2011. This is an indication of the high snowlines and negative glacier mass balance. Casement Glacier had a much greater thinning below 600m than Davidson Glacier, which leads to greater retreat. The difference is that Davidson Glacier has a steeper gradient from the terminus than most glaciers.
1984 Landsat image

2001 Landsat image

2004 Landsat image

2009 Landsat image

2013 Landsat image

2014 Landsat image

Sinclair Glacier Retreat, Alaska

On December 7, 2014December 8, 2014 By mspeltoIn Glacier Observations

Sinclair Mountain is on the east side of the Lynn Canal in southeast Alaska. The mountains hosts too substantial glacier, the south flowing unnamed glacier is referred to here as Sinclair Glacier. This glacier terminated in a lake in the 1982 map of the Skagway region. I observed this glacier from the air in 1982 and it was ending in this lake. Here we examine Landsat imagery from 1984 to 2014 to identify changes.
USGS Skagway map

Google Earth Image

In 1984 the glacier ended at a prominent peninsula in the lake, red arrow in each image, the lake was 1700 m long. The snowline was at 950 m, indicated by the purple arrow, this was at the end of the melt season. The glacier was joined by two tributaries from the west side, orange arrows. In 1986 there is a small amount of terminus retreat visible. By 2001 the glacier has retreated out of the lake, which is 2.9 km long. By 2004 the southern tributary at the orange arrow is no longer connected to the glacier. The glacier has retreated 1.3 km from 1984-2004. The snowline is at 950 m with a month left in the melt season. In 2009 the image is not great quality, but the northern tributary is still connected to the main glacier by a thin tongue of ice at an icefall at 850 m. By 2013 the northern tributary is no longer connected to the main glacier, there is bare rock extending across the full width of the former icefall area. In 2014 the image is from the end of July and the snowline is already above 950 m. It is evident that the glacier will lose nearly all of its snowcover by the end of the melt season on October 10th. The glacier has retreated 900 meters since 2004, and 2.2 km since 1984. The recent loss of tributaries indicates less contribution of ice to the glacier and that retreat will continue. This retreat is the same as that of nearby Field Glacier, Meade Glacier and Ferebee Glacier.

1984 Landsat image

1986 Landsat image

2001 Landsat image

2004 Landsat image

2009 Landsat image

2013 Landsat image

2014 Landsat image

Cloud Peak Glacier Retreat, Wyoming

On December 4, 2014 By mspeltoIn Glacier Observations

Cloud Peak is the highest peak in the Bighorn range of north central Wyoming, a cirque on its east side hosts the only significant glacier in the range. This glacier was photographed in 1903 and has lost much of its volume since then. Rahn et al. (2006), page 44, estimated that if the melting continues at the rate that determined in 2005, Cloud Peak Glacier would disappear between the years 2020 and 2034. They used repeat photographs to estimate glacier volume as 506 million cubic feet in 1905, 205 million cubic feet in 1966 and 78 million cubic feet in 2005. The latter value is likely too low, as it implies a glacier thickness of just over 10 m on average, yet there is active crevassing, which typically requires 30 meters of thickness. A typical volume-area scaling law also yields a thickness of 30 m (Bahr, 2014).

Here we use Google Earth images from 1994, 2006 and 2010 to observe more recent changes. The red line is the outline of the glacier in 1994. In 1994 the glacier had a length of 580 m on average across the glacier front. The glacier had retreated 280 m from the Little Ice Age moraine crosscutting the lake. By 2006 the terminus has retreated 65 m. In 2010 the terminus has retreated an average of 105 m. Just as importantly the top of the glacier has receded 75 m, pink arrows indicate this area. The net results is that total glacier length has declined from 580 m to 380 m on average. The glacier has an area in 2010 of 0.20 square kilometers. Given retreat of the top and bottom of the glacier the glacier will not survive (Pelto, 2010). However, the glacier will not disappear in the next two decades unless the melt conditions increase substantially. This retreat is similar to the nearest glaciers to the north in the Beartooth Mountains of Montana and to the west in the Wind River Range of Wyoming.

1994 Google Earth Image

2006 Google Earth image

2010 Google Earth image

Sovereign Glacier Retreat, Talkeetna Mountains, Alaska

On November 28, 2014 By mspeltoIn Glacier Observations1 Comment

Sovereign Glacier is on the northeast side of the Talkeetna Mountains, Alaska and drains into the Talkeetna River. The Sovereign Glacier, red arrow, was joined by a tributary from the south in the map image, pink arrow. Molnia (2007) noted that all glaciers in the region have retreated since the early 1950’s when the area was mapped and that all the major termini were retreating and thinning in 2000. Here we examine Landsat imagery from 1986 to 2014.

In 1986 the glacier terminates at the red arrow at the valley junction. The tributary to the south, pink arrow has separated from the main glacier and ends in a proglacial lake. In 1989 retreat is evident during the last three years with an expanding proglacial lake at the pink arrow, and the glacier terminus no longer reaching the valley junction, red arrow. By 2001 the glacier has retreated most of the distance from the red arrow at the 1986 terminus location to the yellow arrow, the 2014 terminus location. The former tributary glacier has receded from the proglacial lake. In 2009 there are two new outcrops of bedrock in the upper portion of the glacier indicating glacier thinning near the equilibrium line at 2000 m, at green arrow. By 2014 the main glacier has retreated 1100 m from the 1986 position, red arrow, to the yellow arrow. The tributary glacier at the pink arrow has retreated 400 m since 1986. The green arrow indicates further thinning of the upper glacier since 2009. The thinning upglacier indicates that retreat will continue. The retreat parallels that of nearby South Sheep River Glacier. This thinning in the upper glacier is similar to that of Lemon Creek Glacier as well (Pelto et al, 2013).

1986 Landsat image

1989 Landsat image

2001 Landsat image

2009 Landsat image

2014 Landsat image

South Sheep River Glacier Retreat, Alaska

On November 23, 2014November 28, 2014 By mspeltoIn Glacier Observations1 Comment

South Sheep River Glacier is the informal name of the longest glacier in the Talkeetna Mountains of Alaska. This glacier is the headwaters of the Sheep River and is comprised of two major glacier branches from the east and west meeting and turning north down the Sheep River valley. Molnia (2007) noted that all glaciers in the region have retreated since the early 1950’s when the area was mapped. Molnia (2007) noted that all the major termini were retreating and thinning in 2000. Here we examine Landsat imagery from 1986 to 2014. In the early 1950’s the glacier extended 5.5 km north down the Sheep River Valley from the main glacier junction, red arrow.

USGS Map
In each image the red arrow indicates the early 1950 terminus position, the yellow arrow the 1986 terminus and the pink arrow the 2014 terminus position. In 1986 the glacier had retreated 2.5 km from the 1950’s position. The terminus is at the mouth of the first significant glacier valley draining into the Sheep River from the west. The medial moraine extending to the terminus from the glacier junction is quite prominent. There is a small tributary at Point A that joins the eastern branch of the glacier. In 1989 the snowline on the glacier is at 1700 m. By 2001 the glacier has retreated substantially from the yellow arrow and side valley from the west. In 2009 the snowline is quite high at 2000 m. Th eastern tributary is quite thin beyond the junction, and adds little ice to the now short northward flowing segment. The late Sept. 2014 Landsat image is after a fall snowstorm and the snowline has lowered. The terminus is now at the pink arrow a 4.5 km retreat since the early 1950’s. The glacier has retreated 2 kilometers since 1986. The tributary at Point A now terminates 600 meters from the eastern branch. The glacier flows just 1 km north from the main junction versus 5.5 km in 1950. The terminus remains thin, and the narrow eastern tributary appears ready to separate from the west flowing tributary. This is not an imminent change, but is inevitable. The retreat is the same as that of nearby Sovereign Glacier and glaciers to the south, Pedersen Glacier and Fourpeaked Glacier

1986 Landsat image

1989 Landsat image

2001 Landsat image

2009 Landsat image

2014 Landsat image

Tchap Dara Valley Glacier Retreat, Afghanistan

On November 15, 2014 By mspeltoIn Glacier Observations1 Comment

The Wakhan Corridor in Afghanistan is quite remote. A look at maps or Google Earth will indicate the lack of even place names except in the main river valleys. The Secret Compass uses this fact to advantage for expeditions in the region. Here we examine three glaciers north of Sarhad two draining into the Tchap Dara Valley. Haritashiya et al (2009) examined fluctuations of 30 Wakhan Cooridor glaciers from 1976-2003. They found that 28 of the glaciers had retreated.
Here we examine Landsat images from 1998, 2002 and 2013 with the green arrows pointing the 2013 terminus position of the northern glacier, the red arrows to the 1998 terminus position of the center glacier and the yellow arrows indicating the 1998 terminus location of the western glacier. The blue arrows indicate ice flow.
Google Earth image

In 1998 the red arrow indicates the terminus of the center glacier, which also has an ice cored medial moraine that extends nearly across the entire proglacial lake that the glacier terminates in. The northern glacier extends beyond the green arrow. The western glacier extends to the yellow arrow filling much of a small basin. In 2002 there is little evident change at the northern glacier. The center glacier has retreated leading to lake expansion, and the medial moraine extending into the lake is also shorter. The western glacier no longer reaches the yellow arrow. By 2013 the northern glacier has retreated 200 meters to the green arrow. The center glacier has retreated 400 m leading to the same amount of lake expansion, the medial moraine no longer extends into the main lake basin. The western glacier no longer reaches a lake that has developed in the basin at the 1998 terminus position. The retreat is 300-400 meters. The retreat over 15 years is substantial for small glacier like this. This parallels the retreat at nearby Zemestan Glacier and the Emend River headwaters glaciers.
1998 Landsat image

2002 Landsat image

2013 landsat image

Glaciar Del Humo Retreat, Argentina

On November 6, 2014November 8, 2014 By mspeltoIn Glacier Observations1 Comment

Glaciar del Humo is in the Mendoza Province of Argentina. It drains into Lago Atuel and is one of the headwaters of Rio Atuel. Rio Atuel has hydropower development above and within the Rio Atuel Canon. The Nihuil dam and reservoir above the canyon and four more dams within the canyon, including Valle Grande Reservoir.
Le Quesne et al (2009) examined the retreat of glaciers in the Central Andes and reported the retreat of Glaciar del Humo as 3200 m from 1914-1948, 700 m from 1948-1970 and 660 m from 1970-2007. Here we utilize Landsat imagery to observed changes from 1990 to 2014.
Google Earth Image

Google Earth Image of Valle Grande Reservoir on Rio Atuel

In each image the red arrow marks the 1990 terminus, the yellow arrow the 2014 terminus and the purple arrow a glacier on the west side of Humo. In 1990 the Glaciar del Humo extended down valley ending at the red arrow at 3200 m. The side glacier ended less than 200 m from the main glacier. By 2000 the terminus had retreated 250 m. In 2003 there is little change from 2000. By 2013 the side glacier is separated by 350-400 m from the main glacier. The snowline is in the main accumulation of the glacier. In 2014 the glacier has retreated 900 m from the 1990 terminus position. The terminus is quite thin indicating that retreat will continue. There is also limited retained snowpack on the glacier in 2014, which would lead to mass losses and ongoing retreat. The retreat of this glacier follows that of others in the region, note maps from Glaciares de Argentina

Landsat image 1990

Landsat image 2000