To answer that question, it makes sense to travel there and take samples yourself. Together with colleagues from the Chinese Academy of Sciences and the University of Massachusetts in Amherst, I spent the summers of 2013 and 2014 taking snow samples from four different glaciers in Kyrgyzstan. The Abramov Glacier is found in the northern part of the Pamir Mountains, while the other three glaciers are located at the heart of the Tien Shan Mountain Range. The field measurement campaign was organised by the University of Fribourg (Switzerland), the German Research Centre for Geosciences (GFZ), and the Central Asian Institute for Applied Geosciences in Bishkek. The campaign participants aim to take regular measurements from the glaciers in order to analyse their snow balance and thus calculate the water reserves of Central Asia. This work is being carried out within the framework of the Swiss project CATCOS and the Central Asian Water (CAWa) research network.
Collecting samples is easier said than done; the whole exercise requires lot of logistical preparation and patience. Packing and sending boxes and travelling to the country is easy. The first potential hindrance is encountered at customs, where the clearance process for our equipment can take some time. On our first trip to Kyrgyzstan, the boxes were only ‘released’ late in the evening, at which point it was impossible to postpone our departure for the glacier. That certainly tests your patience, because our work is impossible without the necessary equipment. Fortunately, everything went to plan this summer.
Heavily laden, we left Bishkek, where the temperature climbs above 30 degrees celsius in summer, for the Abramov Glacier in the south towards Tajikistan. Although two days in a car might sound boring, the journey is really quite spectacular, because you pass plateaus and many yurts en route, getting an impression of the country.
When the road ends, you’ve arrived in the Abramov Valley. From this point on, the equipment has to be carried by donkeys or mules. While we’re happy not to have to carry everything ourselves, we’re quickly reminded why mules are famous for being stubborn. Patience and teamwork are once again called for when crossing perilous mountain streams. In the evening, we reach the foot of the glacier at an altitude of 3,800 metres and set up camp for about a week.
The following morning, we head straight off to take the first snow samples from the glacier. We’re aware that we’re on higher ground and it’s also quite cold in comparison to the capital city. We arrive after four hours and start digging a snow pit. Depending on how much snow has fallen in the year, we need to dig from a few centimetres to two metres deep. Usually, an ice lens (a layer of ice a few centimetres thick) or a very dirty layer indicates that we’ve dug ‘one year deep’. This means that we’ve dug deep enough and can begin taking measurements and samples.
We’re interested in finding out how much snow has fallen in one year, how dense it is, and how many layers of dust one can ascertain. The snow samples are placed in small bottles to be tested later in a laboratory. Oxygen isotopes allow us to determine whether the individual snow layers were formed in summer or winter. Other chemical parameters can tell us how much dirt was deposited and, with additional model analyses, we can make an informed guess as to where that dirt came from. Here, it’s particularly interesting to see how much mineral dust from the deserts in the region has been transported to the glaciers. Emissions from forest fires also leave a specific trace. But dust doesn’t just come from natural sources. Human emissions, which lead to air pollution in cities, are also transported here. This particulate matter is not only a health hazard; it also has adverse effects on the glaciers. Soot particles, in particular, can darken the bright glacier surface. As a result, more solar radiation is absorbed and the snow melts more quickly.
The glaciers of Central Asia have been shrinking since the 1970s. The water supply – for agriculture and household use among other things – is highly dependent on the rate of snow and glacier melt. That’s why it’s so important to be able to make reliable prognoses of the future water supply in the context of climate change in a region as sensitive as Central Asia.
Photographs by Julia Schmale