MASSIVE ROCK MOVEMENT IN BLACK CANYON

Was just working on a project that starts on a 65-meter OW that forms the opposite (left) edge of The Flakes route namesake flake. 3 weeks ago I left 5 big bros in there planning to fix them for me and for future parties to climb it without having to carry quite as huge of an OW rack. The last 2 days Jared Ogden and I went in for the send. We approached from above and on the pitch above the OW, while placing directional cams to get down an angling pitch, I noticed the cams didn’t seem to fit the same as they had 3 weeks earlier and a section that had been rattly finger sized seemed to be now solid hand jams. I thought it must just be in my head. Then I started down the OW, and all 5 big bros I’d placed had expanded 1 inch in the last 3 weeks! The collars were where I’d left them, but now there was an inch of thread showing between the collars and the tube - the springs pushed the bros open more as the crack widened, with the collars left in place as quite accurate indicators of how much the crack had widened. We bailed upwards, terrified because we had to climb a full pitch on the feature to get off of it. The feature that moved (or is moving) is 250-300 feet tall and probably 40 feet wide on average. Craziest thing I’ve witnessed in 40 years of climbing. Reported to the NPS. Climbs that are threatened are The Flakes and Night is Dark and Full of Terrors. The thing is probably going to sit there for 10,000 years, but it may be good to give it a winter or 2 of freeze thaw to settle into it's new position or fall...

The Black canyon is certainly dark and full of terrors.

That gives me the heebie jeebies.

Russ Walling wrote: Maybe the outward pressure of the fixed BigBros is opening the fissure...?

nawmean?

Cheers

DMT

Dude, your big bros are opening the crack!

Edit: dammit, Russ beat me to it!

You're complaining about loose fingers turning into good hand jams? Don't look a gift horse in the mouth. 

Sixer to whoever trundles that thing on video...hell...maybe a twelver

Woah,,, that sounds scary Topher! Is it possible the wind spun the collars back a little bit? I guess not if they were tight before and set and loaded,,, Trundle time? Maybe there is a 65meter finger crack under the Flake!?!

topher donahue wrote:  The thing is probably going to sit there for 10,000 years, but it may be good to give it a winter or 2 of freeze thaw to settle into it's new position or fall...

Seems like heat & thermal cycling plays a large part in Yosemite rock falls. Wonder if it is more likely to come off in the spring or fall where the temp swings are greatest.

Thanks for sharing, Topher.

The geologist in Yosemite uses BigBro looking measuring devices to see how much some areas were moving, and it was pretty radical.  Like a foot or something crazy like that.

It would make sense that if the feature is 200-300 feet tall, it could expand and contract a pretty small amount, percent-wise, and still move perceptibly. 

Is it possible that this is a regular cycle, something like ice forming then melting in cracks in the rock that makes them move back and forth with the seasons? Moving that much in 3 weeks has to either be a cycle or, as you point out, an indicator that some big change is going on.

Thanks for taking the Flakes off my list!

See ALL the light grey rock.....it ALL came down in 2003 ! (yes, the whole face: Petit Dru)  and, if I rememeber correctly, a party climbed it about 2 weeks before the "crash".

notmyname wrote: Thanks for taking the Flakes off my list!

+1000

Could this thing potentially topple over onto the opening pitches of Astrodog if it fell the wrong way?! Sort of looks like it from photos of South Chasm.

Charles Vernon wrote:

+1000

Could this thing potentially topple over onto the opening pitches of Astrodog if it fell the wrong way?! Sort of looks like it from photos of South Chasm.

Better yet, maybe it will create a land bridge rendering the Tyrolean obsolete.

the resulting massive cave would likely be the future of hard sport climbing in the US.  in all seriousness, the use of big bros to open up the crack is obviously chipping :)

topher donahue wrote: Was just working on a project that starts on a 65-meter OW that forms the opposite (left) edge of The Flakes route namesake flake. 3 weeks ago I left 5 big bros in there planning to fix them for me and for future parties to climb it without having to carry quite as huge of an OW rack. The last 2 days Jared Ogden and I went in for the send. We approached from above and on the pitch above the OW, while placing directional cams to get down an angling pitch, I noticed the cams didn’t seem to fit the same as they had 3 weeks earlier and a section that had been rattly finger sized seemed to be now solid hand jams. I thought it must just be in my head. Then I started down the OW, and all 5 big bros I’d placed had expanded 1 inch in the last 3 weeks! The collars were where I’d left them, but now there was an inch of thread showing between the collars and the tube - the springs pushed the bros open more as the crack widened, with the collars left in place as quite accurate indicators of how much the crack had widened. We bailed upwards, terrified because we had to climb a full pitch on the feature to get off of it. The feature that moved (or is moving) is 250-300 feet tall and probably 40 feet wide on average. Craziest thing I’ve witnessed in 40 years of climbing. Reported to the NPS. Climbs that are threatened are The Flakes and Night is Dark and Full of Terrors. The thing is probably going to sit there for 10,000 years, but it may be good to give it a winter or 2 of freeze thaw to settle into it's new position or fall...

It would be interesting for someone to monitor this for a few years.
Maybe the warming as spring turns to summer causes this expansion every year.

On a related forum discussion about cracks changing width, someone posted a link about a study of some flake in Yosemite. They found that the crack behind the flake expanded in summer, contracted in winter, but over the course of a few years had a net expansion.

This thread got me interested in what is "normal" movement of a big feature. Hard to nail down but this Smithsonian article quotes Greg Stock, who is on MP, about a much smaller flake he monitored in Yosemite that would expand and contract nearly a half-inch in the course of a daily heat cycle.

​Article Here​​​

Señor Arroz wrote: This thread got me interested in what is "normal" movement of a big feature. Hard to nail down but this Smithsonian article quotes Greg Stock, who is on MP, about a much smaller flake he monitored in Yosemite that would expand and contract nearly a half-inch in the course of a daily heat cycle.

Article Here

Damn, that's pretty crazy. That difference could make something a hand crack in the morning and then a fist crack in the afternoon. So I guess it's a 5.9 if you climbed it in the am and a 5.10 in the pm. That means I get to spray about how my afternoon send was so much better than your morning send, right?

Regarding the speculation that it could be thermal expansion, freeze thaw or cyclical change: this is possible, but we've been working on the route since 2004 and have been on the flake that moved in the early spring, early summer, early fall, late fall and in both scorching hot and sub-freezing conditions and the crack was always the same until that 3 week window this spring - a period without hard freezes, extreme high temperatures or anything other than moderate conditions. I make no claim to know what caused it, but if it is cyclical it is a recently started cycle.

Read Walter Bonatti's account of his ascent on Les Grandes Jorrace (sp?) with Pierre Mazaud (sp?) when a 300' tower fell right past them.