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
The Emend River drains from the Hindu Kush Mountains and joins the Worsaj River and eventually drains into the Amu Darya River. This area is not impacted much by the summer monsoon and glacier runoff is key to summer streamflow. The runoff from the glacier is tapped for extensive irrigation in the valley bottom both along the Emend, and eventually downstream near Taliquan (bottom image). At the headwaters of the Emend River, Takhar Province, Afghanistan are a pair of 3 kilometer long glaciers that are the focus of this post. We examine Landsat images from 2000 and 2011 and a Google Earth image from 2004. In 2000 the western glacier ends in a proglacial lake indicated by the purple arrow in each image. By 2007 the glacier has receded 50 meters from the edge of this lake, and by 2011 the glacier has receded 100+ m from the lake. On the eastern glacier in 2000 a small proglacial lake less than 0.1 square kilometer is at the end of the lake, yellow arrow. In the 2007 Google Earth image the lake has expanded as the glacier has retreated and has an area of 0.25 square kilometers. A small additional expansion has occurred by 2011, with the lake area reaching 0.3 square kilometers. Another glacier to the south also in the Emend River watershed has also experienced lake expansion at its terminus, red arrow. This latter lake has expanded from less than 0.1 square kilometers to 0.3 square kilometers in the last decade. These are all small lakes and do not pose a glacier lake outburst flood hazard.
A closeup view of the terminus area indicates numerous depressions, green arrows. The depressions are ablation hollows, where more dust has accumulated, and then accentuated ablation, the hollows typically form from wind scouring. The hollows are not water filled, Petrov Glacier also featured similar features. This region of the Hindu Kush has not been the focus of detailed glacier studies. Northeast of Takhar Province in the Wakhan Corridor a group of glaciers was examined by Umesh Haritashya and others (2009) and found 28 of thirty had retreated. Zemestan Glacier is one example. The Hindu Kush follows the pattern of the high mountains of central Asia including the Himalaya.
The Wakhan Corridor in Afghanistan is not easy to get to, as a result field study of its glaciers are quite limited. This is where the Global land ice Monitoring System (GLIMS) comes in. GLIMS acquires satellite imagery of glaciated areas, making these images available to researchers and processing them to an extent for inventory purposes. GLIMS is led by Jeff Kargel at the University of Arizona. In the Wakhan Corridor a group of glaciers was examined by Umesh Haritashya and others (2009). This recent GLIMS project examined ASTER and Landsat MSS data 1976–2003, in the Wakhan Corridor of Afghanistan. Of the 30 alpine glaciers of varying type, size and orientation examined 28 glacier-terminus positions have retreated, two have been stationary. The largest average retreat rate was 36 m per year, and the average retreat was 11 m per year. The retreat is evident in a comparison of 1998 Landsat and 2010 Landsat images, note the orange arrow in both. The width and length of the terminus tongue has changed. One of the glacier examined was the Zemestan Glacier. This glacier is 5.3 kilometers long, has an area of 5.2 square kilometers, begins at 5640 meters and terminates at 4800 meters. It is one of many glacier in the Central area of the Wakhan Corridor. Zemestan Glacier has retreated at a rate of 17 meters per year over the study period, a total retreat of 460 meters, 9% of its total length. A comparison of 1998 and 2010 Landsat imagery indicates the retreat of the terminus tongue in width and length at the orange arrows. The glacier has remained snowcovered at its higher elevations at the end of the summer in recent satellite images. This indicates that with current climate the glacier does have a significant accumulation zone and can survive current climate. Continued warming will increase the retreat rate and could threaten its survival. The glacier feeds the Pamir River which in turn drains into the Panj River, to the Amu Darya River and then the Aral Sea. The terminus is on a shallow slope lacks a steep slope and is not extensively crevassed. All of these factors indicate retreat will continue. The glacier has little debris cover unlike many glaciers in the Karakoram-Himalaya-Pamir Ranges such as the Khumbu Glacier or the Zemu Glacier