Record-Deep Pamir Ice Cores Could Hold 20,000–30,000 Years of Climate History

Historic drilling in the Pamir recovers sediment-rich ice that may unlock ancient climate records

High on the Kon Chukurbashi ridge in Tajikistan’s Pamir range, Russian-born glaciologist Stanislav Kutuzov felt the drillhead he was operating slam into bedrock more than 100 metres below the surface. The ice cores recovered by the 15-person international team could provide a rare window into atmospheric and environmental conditions tens of thousands of years ago.

Expedition and logistics
The multinational team — from Switzerland, Japan, Russia and Tajikistan — worked at 5,810 metres (19,000 feet), operating in thin air and temperatures that fell to about −18°C at night. The September mission, funded by the Swiss Polar Institute and the Ice Memory Foundation, originally targeted the higher Fedchenko Glacier but switched to the more accessible Kon Chukurbashi ice cap. Over a week of careful drilling they recovered dozens of 50 cm (20 in) cylindrical cores.

Surprising core quality and colour changes
“The first 50 metres we did in one day,” Kutuzov said, but the team began to encounter poorer core integrity and much higher dust concentrations at 70–80 metres. In the final three to five metres the ice turned “dark brownish, sort of a yellowish colour,” a sign the researchers interpret as evidence of very different past environmental conditions. Expedition leader Evan Miles described the lowest sections as “spectacular” and sediment-rich — encouraging indicators for very old ice.

Age prospects and scientific importance
Previous regional cores include Grigoriev in Kyrgyzstan (around 17,000 years) and a disputed older core from Guliya on the Tibetan Plateau. Miles said the Kon Chukurbashi ice appears colder and likely older than Grigoriev, with preliminary hopes of ages in the 20,000–30,000-year range. Because ice traps ancient air bubbles, these cores can reveal past greenhouse gas concentrations and atmospheric composition — data that are unique and critical for understanding Earth’s climate history.

Regional relevance: monsoons and the Pamir–Karakoram anomaly
Scientists are particularly interested in the Pamir because it sits at a climatic crossroads that helps redirect moist air toward the Indian subcontinent. Information about past snowfall, dust and wind preserved in these cores could improve understanding of natural climate variability in inhabited regions and help model how modern monsoon systems may respond to ongoing climate change.

Preservation and analysis
To preserve the material for future study, Ice Memory will store the second core in a −50°C ice cave at the Concordia Research Station in Antarctica alongside samples from other mountain ranges. The first core is scheduled for molecular analysis at Hokkaido University in Japan. This dual approach both allows immediate study with current methods and safeguards material for more advanced analyses in the future — a deliberate “race against time” to protect climate archives threatened by melting.

“This is the best feeling ever,” Kutuzov said on the ridge — a sentiment matched by scientists who hope the cores will considerably extend the regional climate record.

Laboratory dating and detailed chemical and molecular analyses will be required to confirm the cores’ age and to extract the full climate signal. If the optimistic age estimates hold, these samples could become some of the most important paleoclimate records from high mountains outside the polar caps.