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gstock
climber
Yosemite Valley
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Jul 31, 2015 - 11:36am PT
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That is a nice graphic (and I'm wondering why I never thought of putting a person in for scale!), but I should point out that it only shows a few of the largest recent rockfalls and is not a complete charting of the "Biggest rockfalls in Yosemite". For example, a 200,000 m3 rockfall occurred from Taft Point in 1857, a 185,000 m3 rockfall occurred from near Yosemite Falls in 1858, and a 100,000 m3 rockslide occurred at Cookie Cliff in 1982 (http://pubs.usgs.gov/ds/746/ ). The 1996 Happy Isles rockfall was 30,000 m3.
Just wanted to make the point that large rockfalls similar to those shown in the graphic are more common than you might think.
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gstock
climber
Yosemite Valley
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Jul 31, 2015 - 11:57am PT
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^^^^^
"(1) From Wieczorek et al. (1989): "The May 25 shock sent a rock fall from well up the sharp ridge between Sierra Point and Grizzly Peak, which after hitting the base of the slope proceeded southwesterly as a rock avalanche toward Happy Isles and seriously injured two hikers on the Sierra Point Trail. The 15-30 m wide rock avalanche severed the Sierra Point Trail several times, snapping off trees at their bases and obliterating the trail in a mass of boulders. Most of the rock avalanche stopped shortly before reaching the Nevada Fall Trail. Beyond this point a few large boulders ... bounced or rolled across the trail." (2) From Gilliam (1982): "Below Sierra Point, on the main Vernal Fall trail near Happy Isles, is the 60-ton boulder that cut a swath through the trees as it bounded down from the point in the May earthquake." (3) From Jim Snyder (written commun., January 1990): An earthquake-generated slide destroyed 70% of the Sierra Point Trail, seriously injuring two people. The rock fall came from the crest of the ridge between Sierra Point and Grizzly Peak. (4) From U.S. Geological Survey, National Earthquake Information Center (2004): An earthquake of M6.1 occurred at Mammoth Lakes, California, about 70 km east of Yosemite Valley at about 9 a.m. on 25 May 1980."
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Clint Cummins
Trad climber
SF Bay area, CA
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Jul 31, 2015 - 03:45pm PT
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The current correct split rating is 5.9 C2 or 5.12 A0 ,
assuming nothing significant changed in the pitches above the rockfall.
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Kalimon
Social climber
Ridgway, CO
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Jul 31, 2015 - 08:43pm PT
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3.75 million cubic yards . . . holy shit!
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ryankelly
Trad climber
Bhumi
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Jul 31, 2015 - 09:23pm PT
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The Flying Monkeys are dying. Half Dome is falling apart. And now this goofy ass trip report. So weird. I don't get it.
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clinker
Trad climber
Santa Cruz, California
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We teenage Pinnacles climbers were incredulous when we broke our first hold in Yosemite on Peruvian Flake. Granite doesn't break. Our perspective of potential danger was quite a ways off from reality.
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aldude
climber
Monument Manor
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Clint....does this mean that the route no longer goes free?
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cuvvy
Sport climber
arkansas
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Aug 14, 2015 - 12:16pm PT
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All sounds a bit hasty. Not the sharpest"tools" going up so early after you rockfall
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Rhodo-Router
Gym climber
sawatch choss
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Aug 25, 2015 - 06:06am PT
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Slander thread deleted?
Oh, the humanity!
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