Yosemite Rockfall Along Horsetail Fall

[tgtaylor]

https://www.nps.gov/yose/learn/news/rockfall-in-yosemite-national-park.htm

I hope the rockfall didn't screw-up the view of either the waterfall or El Cap's profile from the Merced. I have recently been thinking about going back to shoot a 4x5 of the profile for an enlargement.

Thomas

[tgtaylor]

Here is a photo of the slide site just published by the Chronicle: http://www.sfgate.com/bayarea/article/How-could-anyone-survive-Photos-show-magnitude-12237963.php#photo-14240105
While I am not certain it appears to be directly on the waterfall's path . If that is indeed the case then future images of Horsetail Fall will be a lot different from past images.

Thomas

[Vaughn]

Looks like it was realtively low on El Cap -- probably will not change the Febuarys' images of the fall. Mountains move; some slow, some fast.

May the climber RIP and a quick recover for the other.

[tgtaylor]

Like I said, I could be wrong but it appears to start high. Here is a image I took of it several years back when Fuji Reala first hit the market:

http://spiritsofsilver.com/yahoo_site_admin/assets/images/Horsetail_Falls_2.58130126_large.jpg

Could the area of the slide coincide with where to water begins its downward path?

Thomas

[Vaughn]

I'll backup from my earlier post -- unsure of where it fell from. But I do not expect any significant changes in the Fall.

[tgtaylor]

Another rockfall, much bigger than yesterday's, just occurred in the same area: http://www.sfgate.com/news/article/Huge-hunk-of-falling-granite-kills-1-injures-1-12236768.php

Thomas

[Drew Wiley]

Horsetail Fall is somewhat to the right of where the slabs peeled off. Judging from the long-extant talus mound at that spot, this has been going on periodically for millennia. I've been atop that steep Talus pile with a Sinar. It's pretty damn big. The news stated that just one of the flakes which peeled off this afternoon was 120 by 60 feet in area. I almost got hit by a slab of ice 60 ft wide falling from Horsetail Falls one winter. Geological processes are still alive and well, and downright sneered at a news anchor tonite who insisted that El Cap had to be engineered to be safe for visitors. Good luck with that one!

[John Kasaian]

The slides filled the valley with dust, according to the news. Breathing particulate granite can't be any good.
It's a miracle more people weren't injured by those slides. One can only imagine the horror those climbers must have felt.

[tgtaylor]

I ran across an Ansel Adams image of Horsetail Fall in the exhibition catalog for Ansel Adams at 100:

https://c1.staticflickr.com/5/4357/37423269391_3616474967_o.jpg

It appears as Plate 92 and is titled El Capitan Fall, Yosemite Valley N.D. Apparently he didn't know it as Horsetail Fall or was aware of the unusual lighting phenomenon it exhibits for a few days each year when the conditions are right. He shot this from the rear of the El Capitan parking lot where I shot mine but a little more to the right. I used a 400mm lens on a 6x7 camera (1200mm on 8x10). Note the sunlight reflecting from the notch in the main column which surely the result of an earlier calving.

Thomas

[Fred L]

this looong thread has extremely detailed information and an incredible number of photos showing before and after etc..

that the park geologist (G Stock) contributes to the thread speaks to the quality of the site.


http://www.supertopo.com/climbing/thread.php?topic_id=3014875&tn=0&mr=0

[tgtaylor]

From this photo in Fred's link, it appears the the rock-slide occurred on the left (west) side of the waterfall:

http://www.supertopo.com/photos/39/2/511715_20064_L.jpg

From other photos this appears to have undercut the knob on which the waterfall flows and that knob might well be the next to go.

Thomas

[Drew Wiley]

The main monolith takes a concave turn toward the Dawn wall, North America wall, and El Cap (Horsetail) Falls. This comprises a "book" (like a partially opened book) which funnels everything falling in this general area into the big talus pile below. The boulders are both whitish from the main monolith and darker andesitic rock from the North America-shaped inclusions up there. This recent Rockwall looks like typical joint spelling probably accelerated by frost wedging during the exceptional past winter.

[Drew Wiley]

Spalling, not spelling. Why this darn dumbphone leave things alone and not try to resell (repsell), speak or small (spall) everything? I'd like to toss it off that cliff!

[tgtaylor]

Interesting article in today's Mercury: http://www.mercurynews.com/2017/10/02/yosemite-scientists-probe-why-rocks-fell-and-where-it-will-happen-next/

Thomas