Serac Blocks Khumbu Icefall, Delaying Everest Climbs

A massive serac, or block of glacial ice, has blocked the primary route through the Khumbu Icefall on Mount Everest, forcing hundreds of climbers and their guides to delay summit attempts during the spring climbing season on Nepal's side of the world's highest peak. As of late April, more than 400 foreign climbers with permits are gathered at Base Camp, elevated over 5,300 meters, unable to proceed beyond the unstable ice formation located just below Camp 1.

The serac, estimated at around 100 feet tall and perched at a precarious angle, poses a high risk of collapse and avalanche, according to officials from Nepal's Department of Mountaineering and the Sagarmatha Pollution Control Committee. Specialized Sherpa teams known as Icefall Doctors, who typically install ropes, ladders, and other safety equipment by mid-April, have paused their work to assess the hazard. They are using drones, 3D imagery, and aerial surveys to monitor the serac's stability, but no safe alternative path has been identified. "The risk of avalanche is high and they are waiting for the serac to melt down on its own to a safe level," said Lama Kazi Sherpa, chairman of the Sagarmatha Pollution Control Committee.