By Jessie Yeung, CNN
(CNN) — Anxiety is growing at Everest Base Camp, more than 5,300 meters above sea level.
Hundreds of climbers and sherpas have gathered, eager to summit the world’s most famous mountain as the annual spring climbing season kicks off – but there’s one problem.
A massive serac, or a block of glacial ice, is hindering the route and keeping alpinists in limbo as they wait for it to gradually collapse and clear the way.
Specialized high-altitude workers known as “icefall doctors” have been on site for weeks already, working to map the serac and its position in the notorious Khumbu Icefall, a steep portion of a glacier that makes up one of the most treacherous sections of the Everest route.
At the start of the season, the “doctors” typically “fix” the route by setting up ropes, ladders and other equipment for climbers to use. But this year, they haven’t yet been able to do this because of the unstable serac.
“Icefall doctors are trying everything in their power. They’re using latest technology, 3D imagery, drones, everything to try and get a clear picture as to timing and how feasible it would be for the serac to actually collapse, for it to be safe enough to go up,” said Adriana Brownlee, co-owner of expedition company AGA Adventures, which guides climbers on their Everest attempts.
“There’s been a few ideas flown around about salt and everything, but we just need to let nature take its course,” she added. “If the mountains say no, it’s no, at the end of the day.”
That has left climbers gathering at base camp, with more people arriving as the days go on – raising concerns of potential traffic jams near the summit when the route does eventually open.
Bianca Adler, who is hoping to become the youngest Australian to summit Everest at just 18, reached the base camp on April 20. Before the final summit push, climbers need several days to do “rotations” – climbing up and down several camps on the way in order for their bodies to adjust to the high altitudes.
She was initially planning to begin her rotations in the coming days, but that has been delayed by the serac.
In the meantime, she and other climbers are filling their time by training – doing smaller hikes, climbing nearby ice towers and practicing walking over metal ladders used to cross deep crevasses.
“These icefall doctors have been working on the mountain for over 20 years and they’re really experienced in their job. I trust that they’re doing their best to make sure that everyone has a safe climbing season,” she said.
CNN has reached out to Nepal’s Department of Tourism and the Sagarmatha Pollution Control Committee, which oversees the icefall doctors, for comment.
‘Just respect the mountain’
There’s good reason for caution: seracs have caused fatal disasters in the past.
In 2014, a gigantic serac on a hanging shoulder collapsed, causing an avalanche in the Khumbu Icefall, killing more than a dozen sherpas who were fixing the route ahead of the climbing season. It was, at the time, the deadliest single accident on Everest – before an earthquake caused another avalanche the following year.
Just a few years later, in the fall of 2019, mountaineer Garrett Madison abandoned an Everest expedition due to another serac causing unsafe conditions in the Khumbu Icefall.
It’s not as simple as just trekking across the chunk of ice. When groups of people walk over the icefall, the vibrations of their movement could destabilize the serac, said Gelje Sherpa, the other co-founder of AGA Adventures, who