Japanese researchers drilled two 105-metre ice cores from the Kon-Chukurbashi ice cap at 5,810 m to investigate the Pamir-Karakoram anomaly, where glaciers have resisted melting. One core will be archived in Antarctica and the other analysed in Sapporo to reconstruct past precipitation, volcanic events and temperatures. Scientists hope parts of the cores date back up to 10,000 years and plan to publish initial results next year. The findings could help explain why some glaciers persist and inform broader glacier-protection efforts.
“Extremely Exciting”: Ice Cores From 5,810 m May Unlock Why Pamir Glaciers Resist Melting
A researcher at Japan's Hokkaido University Institute of Low Temperature Science cuts a slice from an ice core sample taken from a glacier in the Pamir mountain range in Tajikistan (GREG BAKER)(GREG BAKER/AFP/AFP)
Dressed in an orange puffer jacket, Japanese scientist Yoshinori Iizuka opened a laboratory freezer and retrieved a fist-sized ice core he believes could hold vital clues for protecting the world’s shrinking glaciers. The sample is part of an international effort to investigate why glaciers in Tajikistan’s Pamir Mountains have largely resisted the rapid melting seen elsewhere.
The Expedition
Earlier this year, Iizuka and colleagues reached 5,810 metres (about 19,000 feet) on the Kon-Chukurbashi ice cap, where they drilled two ice columns roughly 105 metres (345 feet) long. One core will be preserved in an underground archive in Antarctica managed by the Ice Memory Foundation; the other was shipped to Iizuka’s Institute of Low Temperature Science at Hokkaido University in Sapporo for detailed analysis.
What Scientists Are Looking For
The Pamir-Karakoram anomaly — the unusual observation that glaciers in this region have slightly grown or resisted melting — has prompted many hypotheses, from the area's persistently cold climate to increased agricultural irrigation in nearby Pakistan boosting atmospheric moisture. But until now, no long, continuous record existed to test these ideas rigorously.
Ice cores act as natural archives of past climate. Layers of clear refrozen ice point to warm periods with surface melt; low-density layers indicate heavy snowfall or packed snow; brittle, cracked sections suggest refreezing after partial melt. Chemical markers such as sulfate from volcanic eruptions serve as time horizons, while ratios of water isotopes reveal past temperatures. The team hopes parts of the cores extend back 10,000 years, though a warm spell around 6,000 years ago likely removed some older ice.
Laboratory Work and Timeline
Since the cores arrived in November, researchers have logged density, grain alignment and layer structure in freezing storage. In December, AFP observed scientists in the Hokkaido lab cutting and shaving samples in about −20°C conditions. Graduate student Sora Yaginuma emphasized the unique value of each core: "From that single ice core, we perform a variety of analyses, both chemical and physical."
The team expects to publish initial findings next year. Beyond immediate climate reconstruction, preserved cores in Antarctica will allow additional international studies — for example, to assess how historical mining or regional land use changes altered air quality, precipitation and temperatures.
Why This Matters
Understanding the processes that have allowed Pamir glaciers to persist could inform broader efforts to protect or even restore other glaciers, though Iizuka cautions such aims are ambitious. "If we could learn the mechanism behind the increased volume of ice there, then we may be able to apply that to all the other glaciers around the world," he said. "That may be too ambitious a statement. But I hope our study will ultimately help people."
"Extremely exciting," Iizuka added — both for the scientific insight and for the possibility of informing glacier preservation strategies.
