Queulat Norte Glacier, Chile Retreat Creates Two Lakes

 Queulat Norte Glacier in 1987, 2000 and 2016 Landsat images indicating retreat from 1987 (red arrow) to 2016 (yellow arrow). Green arrow indicates former tributary, orange arrow area of  new bedrock exposure and pink arrow expanding medial moraine. Two new lakes have formed due to the 1950 m retreat. 

Nevado Queulat, Chile is the centerpiece of the Queulat National Park in the Aysen Region.  The largest glacier draining the substantial ice cap on this mountain flows north draining into Lago Rosselot and then the Rio Palena.  Here we examine 1987 to 2016 Landsat imagery to identify changes in this glacier.    Paul and Molg (2014) observed a rapid retreat in general of 25% total area lost from glaciers in the Palena district of northern Patagonia from 1985-2011.

In 1987 the glacier terminates against the valley where the valley turns to the east, red arrow.  There is no lake at the terminus. The tributary at the green arrow connects to the main glacier.  There is no evident medial moraine at pink arrow.  There is no exposed bedrock in the accumulation zone at orange arrow.  In 2000 glacier retreat has exposed a new lake that is 900 m across.  The tributary at the green arrow is no longer connected.  A medial moraine s evident at the pink arrow and bedrock is exposed at orange arrow. By 2016 the glacier has retreated south of a second lake that is 700 m across.  Total retreat from 1987-2016 has been 1950 m, 65 m per year.  This is the loss of  15% of the entire glacier length.  The medial moraine has expanded up and downglacier indicating greater melting and an upward shift of the snowline.  The area at the orange arrow is a significant band of bedrock, indicating that this is no longer an accumulation zone. This bedrock is at 1700 m, the current terminus is at 600 m and the top of the glacier is at 2000 m, leaving only a 300 m elevation band in the accumulation zone. Examination of the region just above the terminus indicates significant ablation hollows/depressions indicative of stagnant ice, green arrows.  There is also an area of debris from a subglacial stream emerging at the surface yellow arrow. The retreat is as significant as that of Erasmo Glacier as a percentage of glacier size.

 

2016 Google Earth image of Queulat Norte Glacier indicating retreat from 1987 (red arrow) to 2016 (yellow arrow). Green arrow indicates former tributary, orange arrow area of  new bedrock exposure and blue arrows indicating flow. 

Stagnant nature of the lower glacier in 2016 with ablation hollows/depressions at green arrows and yellow arrow indicating sub-glacial stream that emerges at surface and deposits debris. 

 

 

Semienova Glacier, Kyrgyzstan Area, Volume, Velocity Decline

semienova-compare-landsat

Landsat comparison of Semenova Glacier in 1998 and 2016.  Red arrow is the 1998 terminus, yellow arrow is the 2016 terminus and purple are locations where tributaries are separating from each other or disconnecting from the main glacier.

Semienova Glacier is a valley glacier in the northeast corner of Kyrgyzstan draining into the Sary Dzhaz (Aksu) River which then flows into the Tarim Basin, China. Farinotti et al. (2015) used three approaches to assess glacier change in the Tien Shan from 1961 to 2012.  The results converge on an overall loss of glacier area of 19-27%,a glacier spatial extent of 2960 square kilometers.  They further observed that it is primarily summer melting that has driven the change.  Sorg et al (2012)  showed that glacier shrinkage is most pronounced in peripheral, lower-elevation ranges near the densely populated regions, where summers are dry and where snow and glacial meltwater is essential for water availability. Shifts of seasonal runoff maximum have already been observed in some rivers, and further summer runoff reductions are expected. Li et al (2014) identify a reduction in velocity of a number of large glaciers, including Semienova Glacier  in the Tien Shan from 2007-2011 that is likely due to mass losses.  Semienova Glacier had a peak velocity 10 km above terminus at 12 cm/day, declining to less than 2 cm day in the last 1-2 kilometers.

From 1998 to 2016 the glacier has retreated 500 m, this is a relatively modest retreat for a glacier of this size.  Debris cover has expanded and supraglacial stream networks have expanded indicating an increasingly stagnant terminus tongue, supporting the low velocity observations. There are three tributaries that joined the glacier in 1998, at the 3 eastern most purple arrows, have detached from the main glacier by 2016.  This indicates reduced contributions to the main glacier tongue. The two purple arrows on glaciers flowing into the valley from the south are located where two formerly joined glaciers are increasingly separated. The snowline in the glacier separating the melt zone and accumulation zone was at 4000 m in 2002, 2013 and 2016.  The retreat of glaciers in the region has also been observed in the Barskoon Mountains and Petrov Glacier.

semienova-9-15-2016-sentinel

Sentinel image of Semienova Glacier in 2016.  Black arrow is 1998 terminus, white arrow the 2016 terminus and black dots the snowline in 2016. 

semienova-2013

Landsat images of Semenova Glacier in 2002 above and 2013 below.  Red arrow is the 1998 terminus, yellow arrow is the 2016 terminus and purple are locations where tributaries are separating from each other or disconnecting from the main glacier.  Purple dots indicate the snowline. 

semienova-2002

Himalaya Glacier Index

Himalaya-Pamir-Hindu Kush-Tien Shan-Quilian-Karakoram Range Glacier Change

Below is a list of individual glaciers in the Himalaya and high mountains of Central Asia that illustrate what is happening glacier by glacier. In addition to the individual sample glaciers we tie the individual glaciers to the large scale changes of approximately 10,000 glaciers that have been examined in repeat satellite image inventories. In the high mountains of Central Asia detailed glacier mapping inventories, from GLIMS: (Global Land Ice Measurements from Space), ICIMOD (International Centre for Integrated Mountain Development), ISRO ( Indian Space Research Organisation) and Chinese National Committee for International Association of Cryospheric Science (IACS) of thousands of glaciers have indicated increased strong thinning and area loss since 1990 throughout the region except the Karokoram. The inventories rely on repeat imagery from ASTER, Corona, Landsat, IKONOS and SPOT imagery. It is simply not possible to make observations
on this number of glaciers in the field.

Reqiang Glacier, Tibet———-Ngozumpa Glacier, Nepal
Samudra Tupa, India———-Zemu Glacier, Sikkim
Theri Kang Glacier, Bhutan———-Zemestan Glacier, Afghanistan
Khumbu Glacier, Nepal———-Imja Glacier, Nepal
Gangotri Glacier, India———–Milam Glacier, India
Satopanth Glacier, India———-Kali Gandaki Headwaters, Nepal
Menlung Glacier, Tibet———-Boshula Glaciers, Tibet
Urumquihe Glacier, Tibet———-Sara Umaga Glacier, India
Dzhungharia Alatau, Kazakhstan———-Petrov Glacier,Kyrgyzstan
West Barun Glacier, Nepal—–Malana Glacier, India
Warwan Basin, India—–North Lhonak Glacier, Sikkim
Changsang Glacier, Sikkim——Emend River Headwaters, Afghanistan
Yajun Peak Glacier, Afghanistan—–Godur Glaicer, Pakistan
Tirich Mir, Pakistan—–Longbasba Glacier, Tibet
Lumding Glacier, Tibet—-Rongbuk Glacier, Tibet
Matsang Tsanpo Glacier, Tibet——-Sepu Kangri, China
Jiongla Glacier, Tibet—-Bode Zanbo Headwaters, Tibet
Zayul Chu Headwaters, TibetHkakabo Razi, Myanmar.
Jaonli Glacier, India
In the Russian Altai mapping of 126 glaciers indicate a 19.7 % reduction in glacier area 1952-2004, with a sharp increase after 1997 (Shahgedanova et al., 2010). In Garhwal Himalaya, India, of 58 glaciers examined from 1990-2006 area loss was 6% (Bhambri et al, 2011). They also noted the number of glaciers increased from 69 (1968) to 75 (2006) due to the disintegration of ice bodies. Examination of 466 glaciers in the Chenab, Parbati and Baspa Basin, India found a 21% decline in glacier area from 1962 to 2004 (Kulkarni, 2007). Glacier fragmentation was also observed in this study, which for some fragments represents a loss of the accumulation area, which means the glacier will not survive (Pelto, 2010). The India glacier inventory (ISRO, 2010) identified glacier area losses and frontal change on 2190 glaciers and found an area loss rate of 3.3% per decade and 76% of glaciers retreating. In the Nepal Himalaya area loss of 3808 glaciers from 1963-2009 is nearly 20% (Bajracharya et al., 2011). The Langtang sub-basin is a small northeast-southwest elongated basin, tributary of Trishuli River north of Kathmandu and bordered with China to the north. The basin contained 192 km2 of glacier area in 1977, 171 km2 in 1988, 152 km2 in 2000 and 142 km2 in 2009. In 32 years from 1977 to 2009 the glacier area declined by 26% (Bajracharya et al., 2011). In the Khumbu region, Nepal volume losses increased from an average of 320 mm/yr 1962-2002 to 790 mm/yr from 2002-2007, including area losses at the highest elevation on the glaciers (Bolch et al., 2011). The high elevation loss is also noted in Tibet on Naimona’nyi Glacier which has not retained accumulation even at 6000 meters. This indicates a lack of high altitude snow-ice gain (Kehrwald et al, 2008). The Dudh Koshi basin is the largest glacierized basin in Nepal. It has 278 glaciers of which 40, amounting to 70% of the area, are valley-type. Almost all the glaciers are retreating at rates of 10–59 m/year and the rate has accelerated after 2001 (Bajracharya and Mool, 2009). In the Tien Shan Range over 1700 glaciers were examined from 1970-2000 glacier area decreased by 13%, from 2000-2007 glacier area shrank by 4% a faster rate than from 1970-2000 (Narama et al, 2010).

An inventory of 308 glaciers in the Nam Co Basin, Tibet, noted an increased loss of area for the 2001-2009 period, 6% area loss (Bolch et al., 2010). Zhou et al (2009) looking at the Nianchu River basin southern Tibet found a 5% area loss. 1990-2005. Cao et al, (2010) completed an inventory of 244 glaciers in Lenglongling Range of Eastern Qilian Mountains from 1972 to 2007 and found a 23.5% loss in glacier area. The highest rate of 1% per year of area loss was identified from 2000 to 2007. In the Pumqu Basin, Tibet an inventory of 999 glacier from the 1974 & 1983 to 2001 indicated the loss of 9% of the glacier area and 10% of the glaciers disappeared (Jin et al, 2005).

Pan et al (2011) looking at the Gongga Mountains, China found a 11.3% area loss from 1966-2009. In the Wakhan Corridor, Pamir Range, Afghanistan 30 glaciers were examined over a 27 year period, 1976-2003, indicating that 28 of the glacier retreated with an average retreat of 294 m, just over 10 meters/yr (Haritashya, et al., 2009). The Karokoram is the one range where a mix of expansion and retreat is seen. The anomalous expansions are confined to the highest relief glaciers and appeared suddenly and sporadically (Hewitt, 2005). After decades of decline, glaciers in the highest parts of the central Karakoram expanded, advanced, and thickened in the late 1990s. Many of the largest glaciers in the Karakoram are still retreating including the Baltoro, Panmah and Biafo Glacier, albeit slowly (Hewitt, 2011).

A new means of assessing glacier volume is GRACE, which cannot look at specific changes of individual glaciers or watersheds. In the high mountains of Central Asia GRACE imagery found mass losses of -264 mm/a for the 2003-2009 period (Matsuo and Heki, 2010). This result is in relative agreement with the other satellite image assessments, but is at odds with the recent global assessment from GRACE, that estimated Himalayan glacier losses at 10% of that found in the aforementioned examples for volume loss for the 2003-2010 period (Jacobs et al, 2012). At this point the detailed glacier by glacier inventories inventories of thousands of glaciers are better validated and illustrate the widespread significant loss in glacier area and volume, though not all glaciers are retreating.

This page will continue to be updated as new inventory data is published and new individual glaciers are examined herein. Yao et al (2012) in an examination of Tibetan glaciers observed substantial losses of 7090 glaciers.