A large and unstable ice block in the Khumbu Icefall has disrupted the early stages of the Everest climbing route above base camp, leaving expedition teams waiting for assessments and safer conditions. Nepal’s mountaineering authorities said the ice block, described as a serac, made the section between base camp and Camp One too risky for climbers to move through, prompting delays for hundreds of climbers and their local guides.
Himal Gautam, of Nepal’s Department of Mountaineering, said the serac on the route is unstable and risky for climbers. Officials said they were working with climbers and expedition organizers to evaluate the situation as crews remained at Everest base camp and could not proceed up the mountain.
The Sagarmatha Pollution Control Committee, which typically deploys personnel to help lay the seasonal route, said it would assess the unstable ice structure using an aerial survey. Committee Chairman Lama Kazi Sherpa said the risk of avalanche was high and that the team was waiting for the serac to melt down on its own to a safer level.
Because the Everest route through the Khumbu Icefall depends on fixed infrastructure, including ropes and aluminum ladders anchored over crevasses, the scheduling impact could extend beyond the immediate obstacle. The committee’s assessment and any subsequent route work are closely tied to the timeline for the “Icefall Doctors,” the elite guides who install the yearly climbing route. Officials said that group usually finishes laying the route by mid-April.
The serac is part of the Khumbu Icefall, which authorities described as a constantly shifting glacier cut by deep crevasses and dominated by large overhanging ice. Officials said the section can be as big as 10-story buildings and is regarded as one of the most difficult and trickiest parts of the climb.
In 2014, a chunk of ice broke away from the Khumbu Icefall, triggering an avalanche that killed 16 Sherpa guides while they carried clients’ equipment up the mountain. Officials cited that 2014 disaster as part of the context for why the current instability required caution.
Despite the disruption at base camp, the spring season continues to be managed around limited periods of favorable weather. Officials said hundreds of foreign climbers and about the same number of Nepalese guides and helpers are expected to attempt Everest next month, when there are brief weather windows.
Nepal’s Department of Mountaineering said the spring climbing season ends at the end of May and that it has issued permits to 410 foreign climbers for attempts to reach the summit. With teams waiting at base camp for the serac to become less hazardous, the window for getting through the Icefall and onward toward higher camps is expected to tighten as the season progresses.
The Mount Everest climbing season is timed to a short period when conditions on the mountain are most workable for ascents. Since Everest was first climbed on May 29, 1953, by Edmund Hillary and Sherpa guide Tenzing Norgay, climbers have continued to rely on those narrow windows—and on the ability of route-laying teams to install and secure equipment in a landscape that can change quickly.