Zaroshkul Glacier Retreat, Tajikistan

Zaroshkul Glacier in 1994 and 2018 Landsat imagery. Z=Zaroshkul Lake, A=Developing lake, red arrow=1994 terminus, yellow arrow=2018 terminus and purple dots=snowline.

Zaroshkul Lake is in the midst of the Pamir Range, Tajikistan and is surrounded by glacier clad mountains.  Here we examine Landsat imagery from 1994-2018 of the Zaroshkul Glacier the largest glacier in the basin to identify changes.  The Pamir Range has experienced less glacier mass loss than most other regions of High Mountain Asia, -0.08 m/year from 2000-2016 (Brun, et al. 2017).  This is supported by the sustained but modes volume loss on Fedchenko Glacier, the largest glacier in the region Lambrecht et al (2014).

In 1994 Zaroshkul Glacier terminated in a 500 m long proglacial lake and the snowline is at 4900 m in late summer. The accumulation area ratio (AAR) is ~40%, indicating a significant negative mass balance, needs to be close to 60% to be in equilibrium.  In 2000 and 2001 the proglacial lake has expanded to a length of 700 m and the snowline in both years is ~4900 m, again too high to sustain the glacier size. In 2015 the snowline is just above 5000 m and less than 25 % of the glacier is in the accumulation zone.By 2018 Zaroshkul Glacier has retreated 600 m and the proglacial lake is now 700 m wide.  The lake is impounded by a wide and by all appearances stable moraine. The snowline on 8-18-2018 is at 5000 m with an AAR of less than 30% indicating continued mass loss, that will generate ongoing retreat.  Three valleys to the north of Zaroshkul Glacier at Point A glacier retreat from 1994 to 2018 has revealed formation of a new small proglacial lake.

The significant continued mass loss of Zaroshkul Glacier fits the pattern of larger volume and area losses on smaller Pamir glaciers as reported by Khromova et al, (2006)

Zaroshkul Glacier in 2000, 2001 and 2015 Landsat imagery. Z=Zaroshkul Lake, A=Developing lake, red arrow=1994 terminus, yellow arrow=2018 terminus, and purple dots=snowline.

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.