Seeking information on Yosemite Valley rockfalls

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gstock

climber
Yosemite Valley
Topic Author's Original Post - Mar 26, 2012 - 03:45pm PT
Hi all,

Cleo and I are working on updating the database of Yosemite rockfalls, which now runs from 1857 to 2011 and has over 900 entries. I'm trying to track down information on a few rockfalls that I know happened, but for which we have no database entry.

First, I'm wondering about the date (year, and also month and/or day if known) of a rockfall from El Capitan that took out part of the route "Space"? The approximate source area is shown in yellow in the photo below. I think this happened in the late 1990's or early 2000's, but as I say we have no date for this event listed. Anybody know something about this rockfall?


Next, I'm wondering if anybody knows more about the rockfalls from Quater Domes over the past few decades? Both domes show evidence of recent exfoliation-type rockfalls, and the Reid guide lists 1997 as the year the one on the eastern dome occurred. Anybody have more specific information on that event? Or know anything about when the rockfalls on the western dome occurred? Seems like at least one of those occurred prior to 1998.


Finally, I'd like to open it up to any other reports you may have about rockfalls that you were witness to anywhere in Yosemite. We probably have records of the larger ones (i.e., no need to report the 1996 Happy Isles rockfall), but if you witnessed smaller ones, especially in remote areas of the Valley and/or prior to 2006, then there is a strong possibility we do not have a record of it. I would need at least the year of occurrence, and preferably the month/day or season. It would also be helpful to know the location as specifically as possible, an approximate size (ok to use size examples like toaster oven, washing machine, VW bus, school bus, battleship, etc.), and what the environmental conditions were like (e.g., sunny, rainy, earthquake shaking, etc.). Feel free to post your observations here, or send me an email.

Thanks!

Greg Stock
Yosemite Geologist
(209) 379-1420
greg_stock@nps.gov
nutjob

Gym climber
Berkeley, CA
Mar 26, 2012 - 03:57pm PT
June 2005, early morning, huge fall off Northwest Face of Halfdome. Just after sunrise, sleeping in manzanita on top and east of North Dome Gully. Awoke to sound of fighter planes blitzing the valley. It was the sound of lots of rock whizzing down before a series of big slams (kind of like the garbage trucks emptying a dumpster, but louder) and a rolling thunder. From about 1/2 or 2/3 way up, right of center face. We saw new stuff detaching and mid-air, after the initial impacts. Dust cloud was so big it filled the valley all the way over to Glacier Apron area. I never heard a big news thing about it. My buddy may have gotten video footage of the very tail end and the dust cloud.

Anyone anywhere on the slabs approach to HD would have been ground into paste.
Fluoride

Trad climber
West Los Angeles, CA
Mar 26, 2012 - 05:50pm PT
Bad rockfall on Middle Cathedral just above the catwalk, spring of '04. Was around 11am on a Saturday in May (was up there when it happened). Most of it came down almost directly onto CP of Frenzy and amazingly no one got hurt. Base was splattered with all the debris. Left a noticeable scar on the place where it fell from. Chunk was probably truck sized.
gstock

climber
Yosemite Valley
Topic Author's Reply - Mar 26, 2012 - 07:48pm PT
Thanks for the reports!

Nutjob, I have an entry for a rockfall on June 19, 2005 at 5:45 am, which sounds like the one you described except that it was reported as coming from the the Porcelain Wall rather than from the NW face of Half Dome. However, the reporting party didn't see the rockfall, only the dust and surmised that it came from the Porcelain Wall. From your description it sounds like it would be better to change that to the NW face?

Fluoride, in case you haven't already seen it, here is a photo of the rockfall you witnessed from Middle Cathedral, which happened on May 15, 2004:


'Pass the Pitons' Pete

Big Wall climber
like Ontario, Canada, eh?
Mar 26, 2012 - 07:53pm PT
I've got videos from BUBS on El Cap when the first two pitches of Gulf Stream fell off. The talus rolled a quarter-mile downhill, and the dust cloud was as high as the Nose.

I had them posted on Youtube, but Kate made me take them down. She was all wide-eyed saying, "Holy #$*(@in' #($*% - I was just up there two weeks ago with Erik!"

Did you ever see those? I could email. Send me a PM.
KabalaArch

Trad climber
Starlite, California
Mar 27, 2012 - 12:24am PT
Well, my recollection is hazy with time, but this is an important topic.

The first release I recall was above the 2/3’s point of the Yosemite Falls trail, which resulted in a hiker’s fatality. I thing this was about 1979. The scar above the trail is quite evident.

Shortly thereafter was a release from Eagle Pk, which is still unstable, rendering the Koko’s area too dangerous to climb. This preceded the release about The Folly by 20 years.

Rockfall activity has been increasing at GPA for at least 25 years. First came the release which stripped Monday Morning Slab of all of its mature trees – including the rap tree on the ledge which traverses over to the Point Beyond upper start.

Then, Happy Isles. My partner and I happed to be about midheight Tightrope when a football exploded about 10 feet climber’s left of the 2nd belay…this was about 2 years prior to the catastrophic realease.

Then came the Hinterlands release, which resulted in fatalities from a party on Apron Jam. Historic photos exist of this rockfall – I’ve viewed some taken from S Face Washington. A civil lawsuit was filed against the NPS, alleging that the proximate cause of this rockfall was due to the installation of a new septic./leachfield installation during the course of the GP improvements. But, the findings were that the leachfield effluent was pretty nominal compared to annual spring snow meltw#ter runoff.

I have some post-release photos of the 9 O’clock Wall incident.

The Crane Flat Road was closed on one occasion, due to rockfall at Reed’s area., which covered the westbound lane…this was in about 1990 or so.

According to Matthes, the GPA is composed of Half Dome quartz monzonite, while the Hinterlands is Sentinal granitdiorite. And these two strata are shifting west to east with respect to once another – The Oasis occurs at the bedding seam.

Apparently, the young Sierra is still growing – by my information, Tioga Pass is a full 12 inches taller than it was when I was 14. This is good, because the geologists’ maps I’ve seem, to guide future construction in the Valley, show a talus outfall zone which encroaches about 15-20% onto the Valley floor. In geologic time (which is happening now), this means that the Valley cliffs will eventually be reduced to talus slopes, unless the uplift of the Sierra exceeds its erosion.

Some folks feel that earthquakes help remove debris from ledges, etc. Others claim that earthquakes add more debris.
Clint Cummins

Trad climber
SF Bay area, CA
Mar 27, 2012 - 03:03am PT
- East Quarter Dome: 1994 or later, because Bill Wright's 1994 trip report doesn't mention any loose rock:
http://www.wwwright.com/climbing/tripreports/1994/QuarterDome.htm

 West Quarter Dome: 1993 or earlier, because the 1993 guidebook "Yosemite Climbs: Big Walls" has a photo on p.147 showing the "rockfall area" on West Quarter Dome with a label. (while the East Quarter in the same photo shows no big rockfall scar yet).

Which Reid guide are you referring to which gives a 1997 date to the East Quarter Dome rockfall? The Free Climbs guide is 1994. Is it in the 1998 "Yosemite Select"? I think 1997 is about right. There is a slightly vague post on the Quarter Dome thread from Steve Grossman mentioning Quarter Dome and 1997. He may be able to supply more details.

These posts on rec.climbing indicate that the East Quarter rockfall had occurred by 1999, and John Black stated that it occurred 3-4 years before that:

Dingus Milktoast Jul 12 1999, 11:00 pm
I've been wanting to ask a secondary question (there are TR's
about 1/4 Dome by the way, on Tuan's web page if I'm not
mistaken)...

Looking down Tenaya Canyon from the Meadows, Burl and I noted the
massive rock fall scar on 1/4 Dome. Thing is... I don't remember
seeing it before. Now I have altered more of my brain cell
structure than is advisable and I may be suffering a memory lapse.
But my question is... how old IS that huge rock scar... to the
right of, I believe, the East Face route?

DMT



John Black Jul 12 1999, 11:00 pm
There was a big rockfall about 3-4 years ago on the North Face of East
Quarter Dome. I THINK it has since been climbed, but I'm not sure. I've
heard that the lower 3 pitches of the North Face route are gone. If I were
you, I'd be careful going into that area... it's like glacier point apron
but steeper! :)
-------
Fluoride

Trad climber
West Los Angeles, CA
Mar 27, 2012 - 04:37am PT
Greg, yeah I think I saw that pic. Thanks for posting it again. Man that was nasty. I was stunned no one was hurt by it. A sunny May Saturday morning at the height of the season with Frenzy in it's path. Crazy stuff.

I remember there was a dog at the base that some climbers had leashed to a tree or something and he was missing. The rockfall cut the leash and the dog was found later that day safe and sound back near Camp 4. He ran away from the scene in time.
BooYah

Social climber
Ely, Nv
Mar 27, 2012 - 09:35am PT
Space rockfall was in '95 or '96, I believe. It took the whole 8th pitch.
Mungeclimber

Trad climber
the crowd MUST BE MOCKED...Mocked I tell you.
Mar 27, 2012 - 11:22am PT
Bump
j-tree

Big Wall climber
Classroom to crag to summer camp
Mar 27, 2012 - 11:48am PT
Has anyone been on Space since the rockfall?
Gene

climber
Mar 27, 2012 - 11:55am PT
Greg,

Do you have this one? http://www.supertopo.com/climbers-forum/10974/Boot-Flake-Fell-of-El-Cap-This-Morning

May 1999, late morning. Run away freight train on Clouds Rest. It looked more like rock fall rather than the annual ice shedding event.

g
BooYah

Social climber
Ely, Nv
Mar 27, 2012 - 11:58am PT
It's been done at least twice since that time, j-tree.
gstock

climber
Yosemite Valley
Topic Author's Reply - Mar 27, 2012 - 11:58am PT
Thanks for the 1992 Surgeon General report, Klaus; we have no record of that.

The prominent scar on the west face of Mount Broderick is from several rockfalls occurring in July 2003. That's the scar on the left in the photo below. The larger scar on the right on Liberty Cap is from a rockfall that was triggered by the March 26, 1872 Owens Valley (Lone Pine) earthquake. That rockfall produced an airblast that knocked Snow's Hotel, located at that time below Liberty Cap, off its foundation by a few inches.

j-tree

Big Wall climber
Classroom to crag to summer camp
Mar 27, 2012 - 12:02pm PT
It's been done at least twice since that time, j-tree.

Thank you. Did either team report as to what pitch 8 entails now?

(sorry to hijack the thread, this is my last question about this I promise. It's just hard to find info on Space because of the clutter you get when searching for a route name as common as the word "space.")
BooYah

Social climber
Ely, Nv
Mar 27, 2012 - 12:04pm PT
My beta comes from Jay Selvige(spelling?) Topo says "many bathooks, loose; pitch missing".
gstock

climber
Yosemite Valley
Topic Author's Reply - Mar 28, 2012 - 09:46am PT
Thanks everyone for your responses. I'm still hoping for more specific dates for the "Space" rockfall on El Cap? 1994 versus 1995? Summer versus winter?

One way to go about pinning this down would be too go through any photos of that area from the mid 1990's and try to bracket when the scar appeared. I have a lot of photos from the 1970's and post 2006, but that doesn't bracket it very well.

Here's an offer (made outside of my position as park geologist): Anyone that can nail down the year and season of the "Space" rockfall gets a free copy of "Geology Underfoot in Yosemite National Park": http://mountain-press.com/item_detail.php?item_key=524

Thanks!
Greg
scuffy b

climber
heading slowly NNW
Mar 28, 2012 - 12:13pm PT
May 1975, Somewhere near the big Zodiac circle, but I don't know exactly.
Two falls in the same day. The second one produced a lot of dust.
From six pitches up on Middle Cathedral, our view of Sentinel was totally
obscured. A couple boulders made it just about to Northside Drive.
Melissa

Gym climber
berkeley, ca
Mar 28, 2012 - 12:30pm PT
Greg...I ask my husband about Space. He did what he thinks is the 2nd post-fall ascent with Chris Trudeau in the summer of 1998. To the best of his memory it was done once after the fall "the previous season" but doesn't recall exactly when that was...so climbing season 1997. The first post-fall ascent was "relatively recent" after the fall. His best guess is it fell in Spring 97 and was climbed by fall 97.
gstock

climber
Yosemite Valley
Topic Author's Reply - Mar 28, 2012 - 07:24pm PT
Thanks Melissa, that is very helpful. I'll wait a bit longer see what others may say, but if no more information comes in I'll be asking for your mailing address!
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