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Mighty Hiker
Social climber
Vancouver, B.C.
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Nov 22, 2008 - 10:08pm PT
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I stand corrected, or at least clarified. The Sedan test, if none other, was a thermonuclear explosion. Relatively low yield (103 kilotonnes), and about 1/3 of the energy from fission and 2/3 from fusion. But nevertheless fusion. I wonder if there were other thermonuclear (fusion) underground tests? I'd had the belief that they were generally too large to be done underground, but it seems not.
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cintune
climber
the Moon and Antarctica
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Nov 22, 2008 - 10:24pm PT
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It is an interesting theory, with an awesome name, but I think shockwaves do slow down quite exponentially. Even earthquakes are localized in effect, except for the really, really big ones that totally dwarf all manmade kilotonnage.
The first HD quip made me laugh out loud, gotta say. The second one, not so much.
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wildone
climber
GHOST TOWN
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Nov 22, 2008 - 10:26pm PT
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Anders, it takes a big man to admit they were wrong.
It takes an even bigger man to laugh at that man.
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WBraun
climber
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Nov 22, 2008 - 10:33pm PT
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There shouldn't be any nukes what so ever.
Only a demonic society will have something that useless and destructive. Nukes are no good period.
They've known how to split the atom since the beginning of creation but chose not to, until some rascals wanted just recently.
Children playing with matches unsupervised is what nuclear science is in reality.
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cintune
climber
the Moon and Antarctica
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Nov 22, 2008 - 10:48pm PT
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TGT
Social climber
So Cal
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Nov 22, 2008 - 10:50pm PT
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The B61 which is probably still in service (or a derivitive) is a "dial a Yeld" device from 0.3-170 kt. The 0.3kt is probably what you get from the Fission part of the physics package by itself.
http://nuclearweaponarchive.org/Usa/Weapons/B61.html
I wouldn't be counted in the "atomic broom theory" category.
A few experiences;
We were up on a climb in Black Velvet Canyon, Red Rocks when the then Blue Diamond mine cut loose with a blast across the valley. The shock wave was powerfull enough to push my whole body into the rock. Focused by the topography it felt like when the fat smart ass in elementary school pushed you in the lunch line. But, there was no rockfall.
Shortly after the Landers (7+) quake I got directions to the point where the fault ruptured the surface. The scarp was impressive with a 7 ft vertical lift, 27 ft of displacement to the north, all happening in 27 seconds. There were fissures in the surface that if you droped a rock in they rattled down for probably 50 -100 ft. I have a great photo of my son who was about 9 or 10 at the time standing in the rift, unable to reach the sides with outstretched arms.
There are JTree style formations of seemingly balanced bolders 60-80 ft high within a few hundred yards of the surface rupture.
Nothing was disturbed on those formations!
As far as I know, no climb or feature in J Tree was altered by that quake even though it blew away numerous buildings in the area!
My first time into the Palisades and up the U Notch there were rap slings 30 -60 ft overhead (early 90's, they've all rotted away and been blown to the winds by now) The snow level had changed that much. The old Sierra club guide, (1965) warns about being in the gullies in the afternoon because of rock fall. The normal patern now seems to be a peak in activity shortly after dawn.
Now that the sun is going on hiatus the next few years should cool and I'd expect a whole new pattern to develop.
What does all this mean?
Hell, I don't know, except that some puny, in geological terms follies of humanity probably had no consequence in the Range of Light.
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Ed Hartouni
Trad climber
Livermore, CA
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Nov 22, 2008 - 11:03pm PT
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ok for SoCal the Gutenberg-Richter relationship for earthquake magnitude is:
log(N) = 5.5 - M
where N is the number of earthquakes per year with magnitude ≥ M
This means that for M = 5.7 (our calculation of the magnitude of a 150 kT test) we'd expect 2 of these every 3 years, considerably more than nuclear tests since 1992...
my guess is that the Atomic Broom Theory doesn't quite explain Doug's observation.
Where's Juan when you need him?
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Tarbuster
climber
right here, right now
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Nov 22, 2008 - 11:08pm PT
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Whether true or false, this whole thing makes great sci-fi.
"Where Dirtbags Collide"
It draws such a startling visual, this great wave cleaning swaths of granite all along the countenance of a proud and sturdy range, the effects trickling down as it were to set the stage for our glorious little passtime.
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Peter Haan
Trad climber
San Francisco, CA
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Nov 22, 2008 - 11:24pm PT
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God that was a riot Tarbaby!
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gstock
climber
Yosemite Valley
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Nov 22, 2008 - 11:36pm PT
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I wrote some of this in an earlier post on another thread, but here are some things to think about:
The May 1980 Mammoth Lakes earthquakes, with a maximum magnitude of 6.3, triggered thousands of rockfalls in the Sierra Nevada (Harp et al., 1984, USGS map I-1612), including at least nine here in Yosemite Valley. The atomic broom must have been less efficient than these earthquakes if it left that much loose debris to be dislocated in 1980.
I would think it would take more than a few decades for weathering processes to loosen rocks up again after a good "sweep". I can't claim to know what the rockfall "reset" time is, but fewer rockfalls occur from areas that were glaciated during the Tioga glaciation 18,000 years ago.
I don't doubt Doug's observations based on decades of being out there, but I do want to emphasize a point regarding the purported increase in Yosemite rockfalls over the past few decades. This increase is almost certainly an increase in rockfall reporting rate, not actual rockfalls, and the reporting rate will be higher where there are more people (i.e., Curry Village). Simply put: more people, more documentation, more rockfalls.
In order to properly quantify a change in rockfall rate, cliffs must be closely monitored over many years. We have started using terrestrial laser scanning (lidar) to make cm-precision maps of Valley walls for this purpose, and plan to repeat the scans every few years.
Greg
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Mighty Hiker
Social climber
Vancouver, B.C.
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Nov 22, 2008 - 11:58pm PT
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(Laughing, of course.)
I don't know about Werner, but I'm fairly fond of nuclear fusion myself. It powers the sun and keeps us warm and toasty. It indirectly created the elements that form the earth.
But I agree that we've maybe let a djinn out of the bottle, when creating weapons using such things. Pandora's box.
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WBraun
climber
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Nov 23, 2008 - 12:06am PT
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"The brahmastra is similar to the modern nuclear weapon manipulated by atomic energy. The atomic energy works wholly on total combustibility, and so the brahmastra also acts. It creates an intolerable heat similar to atomic radiation, but the difference is that the atomic bomb is a gross type of nuclear weapon, whereas the brahmastra is a subtle type of weapon produced by chanting hymns. The subtle science of chanting hymns is also material, but it has yet to be known by the modern material scientists."
Subtle material science is not spiritual, but it has a direct relationship with the spiritual method, which is still subtler. A chanter of hymns knew how to apply the weapon as well as how to retract it. That was perfect knowledge.
The radiation of atomic energy is very insignificant in comparison to the heat produced by a brahmāstra. The atomic bomb explosion can at utmost blow up one globe, but the heat produced by the brahmāstra can destroy the whole cosmic situation. The comparison is therefore made to the heat at the time of annihilation.
Therefore the brahmāstra, more effective and finer than the atomic weapons, was not as blind as the atomic bombs. When the atomic bombs are discharged they do not discriminate between the target and others. Mainly the atomic bombs do harm to the innocent because there is no control. The brahmāstra is not like that. It marks out the target and proceeds accordingly without harming the innocent.
From the Vedic "Srimad-Bhagavatam"
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nick d
Trad climber
nm
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Nov 23, 2008 - 12:24am PT
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Werner, why did you not use that on Cheney?
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Doug Robinson
Trad climber
Santa Cruz
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Topic Author's Reply - Nov 23, 2008 - 02:02am PT
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Cool discussion. You're bringing my assumptions to light -- always a good thing.
Realizing I have a whole different mindset toward the rock in the Valley and Tuolumne than up along the crest further south. All that stone that was under the Tioga glaciation is far more monolithic. Sweep it with ice, it stays swept. We expect to see glacier polish, and I'm even surprised that a mere 18,000 years has spalled off so much of it. Other Westside rock like say Charlotte Dome and the Needles is essentially the same: massive and bulletproof. Tarbuster's "countenance of a proud and sturdy range" is pure Westside.
But the rock up along the crest is wholly different. Blocks and slivery blades, and they aren't all that big. Most of the ridges feel like stacked blocks and if you get off and look from the sides you can see that structure. You can almost feel the frost-wedging levering that stuff around, year by year. A few decades, even after an atomic brooming, seems like plenty to reset it toward loose. Greg, your lasers would go crazy up there.
When Greg mentions stuff that escaped the Tioga glaciation, I think immediately of Cathedral Peak. Or the upper pitches of Fairview. Not hard to find loose blockiness there, even with the pitter-patter of massive human traffic knocking it loose onto parties below. The truly High Sierra is worse.
I think you guys may be right, that earthquakes have a much more powerful cleaning action than the sweep of the atomic broom. Say the three quakes of 6+ in May 1980 are the most recent of any size (true?). By the mid-90s is about when I got nervous enough about increased looseness on the Moon Goddess (Temple Crag) to stay off, and start warning others that I felt it was "no longer a rock climb." A fairly radical thing to say, but there have been two deaths on the route since then. That's 15 years for a reset due to naturally loosening. Way short by Yosemite standards, but along the crest it feels completely reasonable. There are places on the Moon Goddess, viewed from the side, where it appears to be stacked blades from 6" to two feet thick.
The Moon Goddess is an extreme example. Fortunately, most of the highest Sierra is sturdier than that.
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Maysho
climber
Truckee, CA
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Nov 23, 2008 - 08:30am PT
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Interesting discussion, and Howdy Doug!
My family has some history with the test site in Nevada. The step-father of my birth mom, Melody, was an "atomic" veteran, being one of those poor soldier guinea pigs who got to stand close by and watch the blast, wearing goggles, so the army could learn of what effects it might have on nearby humans. He died in his early 30's with cancer all over.
Melody went to the test site for about 20 years straight to protest the testing. I took my son Braden when he was about 10 yrs old to watch grandma get arrested.
I also heard with interest that news report last week that spoke of the carbon 16 in all the trees and all the humans alive in the fifties. Doug I always thought you had a "certain glow" about you, now I know its true!
Peter
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OGBO
Trad climber
Palo Alto, CA
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Nov 23, 2008 - 11:03am PT
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One minor factor left out so far is that the surface effects depend on the depth of the quake as well as the magnitude. On the Richter-Gutenberg scale, the magnitude is computed from a combination of the body motion and the surface motion.
A large number of the apparently delicately balanced rocks in JT, Sierra, elsewhere have been shaken by many quakes over many thousands of years and are actually pretty well settled into more or less stable positions. OTOH, many are just waiting for a small "tipping" push in the right direction to depart in a major way.
Some comparative numbers - the Loma Prieta quake in 1989 is currently listed as 6.9 (down from what they told us right afterwards of 7.1 or 7.2), an energy release of 26.8 MT. The largest nuclear explosion was the Tsar Bomba in Siberia at 50 MT, equivalent to Richter 7.1. The 9.2 Anchorage quake in 1964 was equivalent of 90.7 GT
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Tarbuster
climber
right here, right now
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Nov 23, 2008 - 11:40am PT
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"A large number of the apparently delicately balanced rocks in JT, Sierra, elsewhere have been shaken by many quakes over many thousands of years and are actually pretty well settled into more or less stable positions."
That’s my perception.
A lot of those monolithic tombstones currently standing in Joshua Tree don't fall over during quakes for probably just this reason. Much like those blow up clowns with sand in the base which kids once punched; a lot of the mass is at the bottom. The tops there also are likely rounded smaller from submersive and wind erosion.
As Doug Robinson says however, the eastern escarpment of the Sierra Nevada is characterized differently; very much by a surface, often even a structure, which is "splintered".
(My statement above, "countenance of a proud and sturdy range", puffy, grandiose, intentionally aping the Victorian, was intended to serve a post entirely grounded in humor, although certainly that description is faithful to the impression one receives from afar...)
I was in Mammoth Lakes during those big quakes in 1980 and happened to be bouldering on a large boulder (likely a glacial erratic) which used to sit behind the high school. I couldn’t quite do one of the problems which I had done before; so I stepped back off of the rock to look at it once more and noticed that the sand around the base was undulating and moving.
I watched the big boulder rock back and forth; it wasn’t going to be toppling, but at my back and up on a high crest, coming out of a feature called the Rock Chute (and Finger Chutes maybe?) came spewing toward the ground very large amount of debris.
Also anecdotally, in furtherance of some of these observations up in the Eastern Sierra: I was in the Palisades in summer of 1976. (Some may remember this was a big drought year). We had just done a long loop from Lamark Col, down through the Evolution region, up into Dusy Basin, over Agassiz Col and having arrived late afternoon we were surveying the U Notch from the lateral/terminal moraine of the Palisade Glacier. Glacier Camp it might be called, or thereabouts.
There in the late afternoon we witnessed absolutely massive rock fall: I really thought it was a segmented chunk the size of a freight car, big enough that as we watched it fall it had that slow-moving look as in the movies: like the Guns of Navarone being liberated from their perches, these behemoths came charging down the U Notch and shook the glacier and surrounding ground beneath our feet.
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hossjulia
Trad climber
Eastside
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Nov 23, 2008 - 12:22pm PT
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This is fascinating stuff.
All of these past post talk about ground effects, what about air blasts? I'm no scientist by any means, but I have learned that certain explosives have more of a shattering effect in an air blast situation (as in Avalanche control) then they do if they are on, or in, the ground.
Just how much of an air shock wave would there be from a large detonation, especially if it was done x-number of feet above ground? Enough to topple rocks in the Palisades basin before dawn 100-150 miles away? Was that perhaps a one-of-a-kind test?
As far as concrete numbers of detonations at the Nevada test range, does anyone really think the public has access to ALL test data? I would think knott.
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Tarbuster
climber
right here, right now
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Nov 23, 2008 - 12:27pm PT
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I thought DR was in fact referring to a shockwave which primarily effected a gargantuan air blast.
(I'll have to read it again).
Certainly one of the posters up-thread described an eye-opening air blast scenario of a different nature...
Fun thread!
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Tarbuster
climber
right here, right now
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Nov 23, 2008 - 12:37pm PT
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"Mega-tonnage of blast power rolled out massive shockwaves through the atmosphere. Those pulses cleared the Inyo Mountains and the Funeral Range above Death Valley and slammed into the eastern escarpment of the High Sierra. It’s a direct hit on the highest walls up under the crest, where the shock wave scoured the East Face of Whitney and the magnificent ribs and buttresses of Mt. Russell"
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