Scientists have launched long-term monitoring of Glacier No. 431 in the Murgab River basin, conducting the first comprehensive field expedition to the glacier in early August.

The expedition was carried out jointly by specialists from the University of Central Asia (UCA)’s Mountain Societies Research Institute and the Institute for Glaciers and Cryosphere Studies of the National Academy of Sciences of Tajikistan, UCA told Asia-Plus.

Where is the glacier?

Glacier No. 431 is located in the upper reaches of the Dashtob River, also known as Elisu, in the Eastern Pamirs. It belongs to the Murgab River basin.

The glacier covers about 4.7 square kilometers and is 5.1 kilometers long. Its lower tongue lies at an altitude of around 4,730 meters above sea level, while the upper part of the glacier system reaches approximately 5,700 meters.

It is classified as a valley glacier and has a northeastern exposure.

Until now, this part of the Murgab basin has been largely outside the network of regular ground-based observations. Information on local glaciers has primarily come from inventories and satellite imagery.

Satellite data can track changes in glacier area and boundaries, but cannot fully replace direct measurements on the ice. The region has also lacked a long-term series of field observations that would make it possible to compare annual melting and surface changes on the same glacier.

According to the Soviet-era Catalogue of Glaciers, the Murgab River basin contains 879 glaciers covering a total area of 560.6 square kilometers. Of these, 787 have an area of at least 0.1 square kilometers.

How will scientists measure melting?

During the expedition, researchers installed 12 measuring stakes in the glacier’s ablation zone.

Ablation refers to the loss of snow and ice, primarily through melting. The stakes are drilled directly into the glacier. As the ice surface melts and lowers, a larger section of each stake becomes exposed.

By measuring how much of the stakes is visible during future visits, scientists will be able to determine how much ice has melted over a given period.

Researchers recorded precise geographic coordinates and elevations for all 12 monitoring points, allowing them to return to exactly the same locations in subsequent years.

The measurements taken this year will serve as a baseline for calculating seasonal and annual ice loss and comparing the intensity of melting across different parts of the glacier.

The data will also be used to calculate the glacier’s surface mass balance — the difference between the amount of snow and ice it gains and the amount it loses over a specific period.

Monitoring will continue every year

The August expedition marks the first stage of a long-term research program. Scientists plan to return to Glacier No. 431 every year to repeat the measurements.

The program will also include snow surveys in the glacier’s accumulation zone to assess how much snow is stored there.

At a later stage, researchers plan to install an automatic weather station to collect local data on air temperature, precipitation, radiation balance, wind speed and other meteorological indicators.

Hydrological monitoring is also planned in the area below the glacier. This will help scientists study meltwater and assess its role in the Murgab basin’s water system.

Researchers will combine field observations with satellite data and high-precision geodetic surveys to monitor changes in the glacier’s area, length and volume.

The goal is to build a long-term record of changes in Glacier No. 431 and compare measurements collected on the ground with satellite observations.

Glacier No. 431 joins Tajikistan’s monitoring network

Regular glacier monitoring is already being carried out in several other parts of Tajikistan.

The network includes Glacier No. 457 in the Gunt River basin, the Yakarcha Glacier in the Kofarnihon River basin, the Surkhob Glacier in the Muksu River basin, the Sayyid Nafi Glacier in the Surkhob River basin, the Nisay Glacier in the Obihingou River basin, the GGP Glacier in the Zarafshon River basin and Glacier No. 139 in the Khovarkul Lake basin.

Glacier No. 431 in the Eastern Pamirs has now been added to this network.

Data collected there will be used to monitor seasonal and annual ice loss, changes in the glacier’s surface and its mass balance.

The research is also expected to help scientists better understand the relationship between weather conditions, glacier changes and the volume of meltwater produced.

In addition, the observations will be used to assess the contribution of glacial runoff to the water balance of the Murgab basin and the wider hydrological system linked to Lake Sarez.