Deadly Gyirong Port mudslide traced to massive ice-rock avalanche

A catastrophic mudslide that struck Gyirong Port on the China-Nepal border was triggered by a colossal ice-rock avalanche, according to geohazard experts. The event, which occurred on Wednesday morning, has left at least seven people dead and 554 missing on the Chinese side, with two villagers rescued as of early Saturday.

Professor Fan Xuanmei, director of the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection at Chengdu University of Technology, said satellite and seismic data point to a single, clear cause. A massive ice-rock mass, originating from a slope above 5,000 metres, fell into a gully and rapidly transformed into a debris flow. This flow travelled for roughly seven to eight minutes before reaching Gyirong Port, a key inland trade point between China and Nepal.

Fan described the event as a classic cascading hazard, where an avalanche induces a debris flow. She dismissed speculation that an earthquake or heavy rainstorm directly triggered the event, noting that no such obvious triggers were observed. Instead, she suggested that long-term climate change and the effects of the devastating 7.8-magnitude earthquake that struck Nepal in April 2015 may have contributed to the slope's instability.

The sheer scale and speed of the event made it exceptionally destructive. Based on seismic readings, the energy released by the avalanche and subsequent debris flow was equivalent to a magnitude 5.1 earthquake. The flow also moved at an estimated velocity of 50 metres per second, making it extraordinarily fast and leaving little time for evacuation.