News Category: Glacier Lake Outburst Floods

On 25 October 2025, at around 11:00 a.m., a large ice mass collapsed from the Dehdal Glacier (formerly known as Dedal), located on the northern slopes of the Peter the First Range, near the village of Safedobi in Tajikabad District.

According to the Committee for Emergency Situations and Civil Defence under the Government of the Republic of Tajikistan, a section of the glacier, approximately 2 km long, 25 m high, and 150–200 m wide, broke off and slid down the valley. By 14:00, the situation had stabilized, and no casualties or serious damage were reported.

This is the second collapse of the Dehdal Glacier in recent months. Kamoliddin Nazirzoda, Deputy Head of the Glaciology Centre of the Agency for Hydrometeorology of Tajikistan, explained:

“The activity of the Dehdal Glacier this year can be described as abnormal — no one expected a surge. This glacier is listed among the representative glaciers, and our Centre assessed its condition in 2020 and 2024. According to those studies, there were no signs of an imminent surge; we expected it in 25–30 years. However, this year two surges occurred in a row: the first on 18–19 September, when the glacier advanced more than 4 km, and the second at the end of October, when the ice mass moved another 5 km down the valley. Satellite images show that the activity had already started in early September.”

About the glacier

The Dehdal Glacier originates at an altitude of 4,600 metres above sea level and is a surge-type (or pulsating) glacier, whose movement occurs roughly every 40–45 years, according to the Glaciology Centre of the Agency for Hydrometeorology. Previous active phases of Dehdal were recorded in 1902, 1922, 1974, and 2016.

According to Kamoliddin Nazirzoda, the glacier’s dynamics are directly linked to climatic conditions — namely, the amount of precipitation and snow accumulation in its feeding area.

“After analyzing meteorological data from the past five years, we found that from late spring to early autumn this year, there was almost no precipitation, while temperatures remained high. This led to the degradation of the glacier’s structure. Another contributing factor was seismic activity. Several earthquakes were recorded in the area this year, which could also have influenced the movement of the ice mass.”

Outlook

The glacier’s surface remains active. The residual glacier continues to move forward at speeds of up to 40 metres per day, and there is a risk that another detachment could occur. There is also a risk that the ice mass and sediment accumulated downstream in the valley may subside during heavy rainfall, snowfall, potentially blocking the river channel flowing from the glacier. In this case, a temporary lake could form, and its outburst might damage the bridge on the Dushanbe–Vakhdat–Lakhsh highway leading to the Kyrgyz Republic, as well as affect farmland in the village of Gulrez.

According to the Committee for Emergency Situations, work is already underway in the valley to reinforce riverbanks and protect the bridge and nearby areas in case of new surges or water outbursts.

“We continue monitoring the glacier. In the coming days, our specialists will travel to the site to assess the likelihood of another surge,” added Kamoliddin Nazirzoda.

Why it matters

The recent glacier collapse highlights the urgent need to strengthen disaster risk reduction and establish early warning systems to protect mountain communities – efforts currently being implemented by the “Reducing vulnerabilities of populations in Central Asia from glacier lake outburst floods in a changing climate” (GLOFCA) project near the Said Nasifi (Baralmos) Glacier.

At the same time, it underlines the importance of sustained glacier monitoring and the development of automatic, remote observation systems, which form a key component of the GEF–UNDP–UNESCO Cryosphere Project.