Unsafe conditions on Mount Everest have forced a National Geographic team to cancel plans to climb the rarely traversed West Ridge of the world's tallest peak.
The team was initially slated to ascend via two routes, the West Ridge and the Southeast Ridge, as part of a National Geographic Society and North Face expedition commemorating the 50th anniversary of the first U.S. ascent of Everest.
However, "after looking at aerial photos of the Hornbein Couloir"—a steep gully on the northern side of Mount Everest—"the [West Ridge] route is not safe to attempt this year," expedition leader Conrad Anker said in a statement.
Choosing to cancel the West Ridge attempt was a tough decision, Anker said, "but it's also the sensible thing to do from an experienced climber's—an alpinist's—perspective."
The Southeast Ridge team is still aiming for a summit bid later this month.
West Ridge Too Dry to Climb
Elaborating on the team's blog, Anker said that the normally snowy terrain on the West Ridge region of the mountain looks like bare ice, thanks to a very dry and windy season. This makes climbing difficult with crampons—sets of metal spikes clipped onto boots for traction.
"What we have now is that that surface layer of snow has been stripped away, leaving bare ice," Anker wrote on the blog. "It's very ancient ice that's difficult to climb on. ... That's just the nature of the mountain. Some seasons the routes are not in shape."
The dry conditions also increase the risk of deadly rockfalls on the mountain, explained David Roberts, a mountaineer who has written extensively about Mount Everest.
"If you get plenty of snow, it glues the rock in place," said Roberts, who is not part of the expedition team.
"But if you have unusual warming and nocturnal freezing followed by diurnal melting, the cracks start to expand and the rocks slough off."
Overall, Roberts thinks Anker made the right call. "I was really worried about Conrad," he said. "I think it's very smart that he called it off."
Southeast Ridge Still a "Go"
The poor climbing conditions are just the latest setback for the West Ridge team.
In April Cory Richards, a National Geographic photographer and Anker's climbing partner, was evacuated off Mount Everest after experiencing severe shortness of breath at Base Camp.
Anker is now in the process of securing a permit to join the Southeast Ridge team, which includes National Geographic magazine writer Mark Jenkins and The North Face Global Team Athletes Kris Erickson, Hilaree O'Neill, Sam Elias, and Emily Harrington.
But the Southeast Ridge team could have a difficult climb ahead as well, Everest expert Roberts said.
A recent rock slide and avalanche on the mountain directly threatened the normal route up to the South Col, the most commonly climbed line on Everest's south side.
"It just sounds like a horrible time to be on Everest," Roberts said.