Officials from the park conducted an investigation and determined that the cracking was ongoing, prompting them to take precautionary measures by closing off certain areas.
The newly formed crack has caused partial detachment of a significant rock pillar adjacent to the Super Slide climbing route. In order to mitigate the risk of rockfall, the National Park Service has decided to seal off trails while they continue their investigations. These closures were implemented on August 30 and will remain in effect until further notice.
On Instagram, @tewards climber_stewards, wrote: "Recent assessment of the new splitter by Park Geologist Greg Stock revealed "active cracking (similar to walking on thin ice), as well as rock chips rattling through the upper crack and falling out the lower crack."
Sketchy! The area is officially CLOSED but we know you were dying for more details on "Super Natural," 5.10-, Jake Squier et al so here are some photos"
Jesse McGahey, a Supervisory Park Ranger at Yosemite National Park, told Climbing: “The following week a climbing ranger and a geologist observed it firsthand and they could hear it cracking like a frozen lake that wasn’t consolidated,”
“And there were pieces of rock rattling down the crack without touching it. The park geologist said they’d never seen anything like this. He’s never been able to observe that in his 15 years in Yosemite.”
Over the span of seven days, the crack has reportedly shifted roughly an inch, but the implications for the future remain uncertain. The park officials are concerned about the substantial rock pillar and the possibility of it collapsing.
The timeframe for this potential event could range from immediate to several years. Consequently, until the extent of the threat can be better assessed, certain areas of the park will remain off-limits.
Yosemite Valley is no stranger to rockfalls, as the steep cliffs were formed by a glacier. This dynamic landscape contributes to the park's natural beauty but also presents the risk of rockfall events. It is advisable to avoid witnessing such incidents firsthand.
According to the National Park Service, the presence of water in fractures within the bedrock can lead to increased pressure behind unstable rocks. Additionally, when water seeps into cracks in the rock and freezes, it expands and causes the cracks to widen. This natural phenomenon, known as "frost wedging" or "freeze-thaw," gradually dislodges loose rocks from cliff faces.
They wrote: “Triggering mechanisms like water, ice, earthquakes, and vegetation growth are among the final forces that cause unstable rocks to fall,”
