Seismology for Dummies: Guesstimating nuke test yields

A_Gupta · Post by **A_Gupta** » 04 Jul 2002 00:11

1. Two nuclear explosions no more produce wave interference in measurement of energy than do two light bulbs.

For instance, http://www.bharat-rakshak.com/MONITOR/ISSUE3-6/pok.pdf works only if the two sources in the dipole are coherent.

2. Assuming Pokharan I and Pokharan II were in similar conditions, then there should be little uncertainty in the ratio of Pokharan II to Pokharan I at any particular seismograph.

The paper refered to :

http://www.llnl.gov/str/Walter.html

indicates that the amplitude at a particular Canadian station was, in 1998, twice that in 1974. Then the yield in 1998 is four times 1974.
If 1974 yield is 4-12 kt (as in the paper), then energy in 1998 = 16-48 kt.

Sunil · Post by **Sunil** » 04 Jul 2002 02:19

> Two nuclear explosions no more produce wave interference in measurement of energy than do two light bulbs.

No, not quite. Spontaneous emission (the underlying process of a light bulb) is an intrinsically incoherent process.

Nuclear explosions going off under the earth are more like hammers hitting a elastic surface or like church bells. So long as the explosions are set off at the same time and in the same geological medium, the dyamics of the waves is identical. For the analysis of this it is sufficient to treat them as coherent sources.

> 2. Assuming Pokharan I and Pokharan II were in similar conditions, then there should be little uncertainty in the ratio of Pokharan II to Pokharan I at any particular seismograph

yes all else at the siesmograph being equal. it is here that Nabendu's discussion on the error model assumes significance. The link you have provided appears to side step this part. The yeild is described as 4-12 and then the value for 1998 is obtained by simply multiplying the upper and lower bounds by 4.

I am not sure what error model that is. I have not even heard of such an error model that permits you to multiply the bounds.

Calvin · Post by **Calvin** » 04 Jul 2002 05:22

NK: If we feel compelled to rehash, in EVERY THREAD, the fact that there are some people in western universities that give us no respect, and respect every exposition of tripe put out by one of their own - then we will be compelled to boredom.

Having said that, there is no doubt a need to disseminate this information to the public at large. These sort of threads throw up a lot of technical information that is essential in creating the necessary credibility when we make a case - let us not let that technical information go to waste.

Re: the formation of a cavern, Sublette had a fairly interesting article in the FAS on the indian tests in particular discussing the shape of the surface features in a lot of detail.

shiv · Post by **shiv** » 04 Jul 2002 06:52

Originally posted by A_Gupta:
1. Two nuclear explosions no more produce wave interference in measurement of energy than do two light bulbs.

Indeed. France's last nuclear test in that formerly Pacific atoll and the last Chinese nuke test in Ling Ding (or was it Lop Nor) were not two coherent sources.

But we are speaking of two nuclear tests set off SIMULTANEOUSLY (as in exactly the same time, perhaps sparated by a few nanoseconds)? These are not "coherent sources" that continue to radiate energy like a light bulb. These are single shot, one-off events that send out one pulse of energy. That one burst of energy has been released simultaneously in the same medium.

Questions:

1) Has anybody bothered to ask What experience do the seismological community in the world have of analysing seismic signals from nuke tests conducted EXACTLY at the same time and separated from each other at a distance at which interference can occur?

Ans:The seismologists of the world have nearly zero experience of looking a yields from two simultaneous shots "Nearly zero" because that has been done once before by someone (can't recall now)and no attempt has been made to do anything other than apply the magic equation and sit in cosy cuckoo land.

2) Has any seismologist of note in the world bothered even to think about the fact that two shot simultaneously will interfere with each other?

Ans: No, seismologists "of note" have not been bothered because throughout the history of nuke tests - the tests have been done as single shots. The grovelling Indians who did the tests HAD to be bothered because the tests had to be simultaneous. If a big one was set off so close to the smaller test shafts - the latter would be crushed to juice in the first blast.

3)Has anyone in the seismological community acknowledged (as one would accept any scientists to do) that they do not have experience in looking at signals from two or more simultaneous shots?

Ans: NO. After Pokhran, one station (Yellowknife, Canada) had a seismic signal that indicated the blast at Pokhran to be over 100 Kilotons On the basis of that anyone could claim that Pokhran 1998 tests were 100 kilotons. Why 8, or 20 or 53?

But all this nitpicking only shows up the seismological community for what it is, and may be a waste of time for anything other than identifying the jokers because the point is:

FACT: teleseismology is an unreliable method of estimating yields. It's like a person trying to figure out blood sugar levels by reading knobs on the head.

Kuttan · Post by **Kuttan** » 04 Jul 2002 07:28

teleseismology

Someone here mentioned:

crystallography

as one of the specialities here.

Could it be that Political Teleseismology can be given the alias of

crystallosphereology

?????????????..

BTW, Calvin, thanks for your answer about the caverns - it fits my model of "experts" to a "T".

shiv · Post by **shiv** » 04 Jul 2002 09:04

Originally posted by narayanan:

Could it be that Political Teleseismology can be given the alias of
crystallosphereology
?

crystallosphereology

Rearrange the bold letters for the answer.

Roop · Post by **Roop** » 04 Jul 2002 10:23

Originally posted by Naraynan:
The point here is that some of what is passed off for "physics" in the "prestigious journals" is actually biased, dishonest, "lifafa" science. ... political and ego-based arguments based on calculations which are uncertain by orders of magnitude.

Yes, absolutely! As I have said on this topic in the past, these people, even if they hold advanced degrees and work for "prestigious institutions", are not really acting as scientists in this debate. They are political activists in lab coats.

There are, unfortunately, lots of gullible/grovelling Indians who will automatically assume that Western scientists are invariably truthful, accurate and unbiased, and that Indian scientists, to the extent that they disagree with above, are either lying or incompetent. We have recently had an example of precisely this sort of mental aberration right here on BR.

shiv · Post by **shiv** » 04 Jul 2002 10:27

What is science, and where does it fit in with morality and the search for what is true and correct?

A patient comes to a doctor's office saying that his son has suffered from "a fit" twice over the last 24 hours. The father describes the fits or seizures as fainting followed by uncontrollable jerking of the face, arms and legs with frothing at the mouth for several minutes.

What does the doctor do?

The doctor could tell the father:

a)"You're talking rubbish. This can't happen. Go away and don't bother me."

or the doctor could say:

b)"OK, let's see what we can find."

If he does the latter, the doctor would first check the child out for the usual causes of fits, including fever, infections, injuries, drugs, biochemical abnormalities and if all these came up negative, he would start checking out the child's brain for causes in the brain.

The doctor may order scans and electrical monitoring of the brain and might even keep the child under observation to do observe a fit. (Note that slicing up the child's brain to look for causes is not allowed)

If nothing shows up (as is often the case) what does the doctor do?

At this stage the doctor could say:

a)"This is all rubbish. All the tests are normal. You are lying. The child has no fits."

or the doctor could say:

b)"We have a problem. The child has had fits, but we have not found a cause."

I wrote this story to illustrate what is happening in the field of seismology in relation to nuclear tests. Some "prominent" seismologists have a tendency to rubbish what anyone says because they do not find evidence from their indirect methods. They do not say "There is a problem. XYZ says that this occured. It may have occured and only XYZ can have direct proof for his claim, but our indirect methods show only this."

What we hear is the unmistakable insinuation "Hey that did not occur. XYZ might have a reason for misleading everyone."

In any such situation, for a scientist, there is always the doubt, "I may be right. I may be wrong". The chap who asserts "I am right, and only my methods are infallible" is frequently one who has an agenda beyond mere knowledge.

That is my take on what is going on.

Calvin · Post by **Calvin** » 04 Jul 2002 17:53

Narayanan: Re: Comments about experts and T's, note that Sublette (member of the Federation of American SCIENTISTS) only has a BA in History. No science, or physics as far as formal training.

Umrao · Post by **Umrao** » 04 Jul 2002 18:01

Faraday was not a certified MS
Bell was not a BE/B.Tech/BS in ECE
Ramar Pillai (of Herbal Gas) was not a BS, as he has given seminars in DRDO/IITs.

Calvin · Post by **Calvin** » 04 Jul 2002 19:43

Spinster - no one is suggesting that one needs a PhD in poultry to tell a good egg from a bad one. Its entertaining to watch a History-major critique some of the foremost physicists of our times.

A_Gupta · Post by **A_Gupta** » 04 Jul 2002 20:15

First, what we agree on :

Seismography, without extensive calibration, is next to useless in measuring the yield of underground nuclear explosions.

-----------------------------

Next, some discussion :

From the papers cited, the attenuation constant (a in the equation mb = a + 0.75 log Y), is a property determined by the geology of the test site, varies significantly from site to site, but is the same for a given site for nuclear explosions over a wide range of magnitudes. Presumably this has been validated during extensive nuclear testing of the superpowers etc.

While Indian scientists have presumably calibrated Pokharan by on-site measurements, the value of "a" for Pokharan is a secret. Informing the world of an exact yield of the 1974 test would give away "a" once and for all. Indeed, http://www.llnl.gov/str/Walter.html reports that for 1974 :

However, Indian scientists and officials stated a large range in the yield estimate-4 to 12 kilotons.

The reason for not being precise can rationally only be to keep the value of "a" for Pokharan an unknown.

----------
Now for the stuff we disagree on :

1. In dealing with "a", we are not dealing with a quantity that has random variation. It is more akin to the situation, that an ancient text tells us that from city A, town B was 8 yojanas and town C was 16 yojanas. Then we know that town C was twice as distant as town A. The yojana is known to be 8000 lambas, say, and the lamba was derived from an artifact kept at temple XYZ, that has since been lost to history. All we know now is that the lamba is the length of a human stride, say 1 meter to 1.25 meter. All we can say is that a yojana is 8 km to 10 km, then town B is 64 to 80 km from city A, and town C is 128 to 160 km. There is no compounding of errors in the ratio of the distances, only in the absolute measure.

That is, "a" has some definite value, the uncertainty is not statistical, it is because of secrecy .

2. Taking the interference theory seriously, 45 kiloton and 10 kiloton explosions will not produce the interference pattern advertised because of the difference in magnitudes (think of a bright source and a dim source.)

3. In any case, I do not take the interference theory seriously. Two simultaneous explosions are not akin to striking two tuning forks simultaneously ; it is similar to striking two bells simultaneously. A wide spectrum is excited and neighboring spectral components differ in phase relationships, so that summing over all components destroys interference.

4. Given that you know how to go "bang" , mastery of the technology is not demonstrated by making a bigger bang - it is demonstrated by being able to meet design objectives. India cannot annouce correctly the designed for yield and actual yield without giving away once and for all, the value of "a" for Pokharan; and if the policy is to keep "a" secret, then one has to keep in mind that the announcements made by India are deliberately obfuscating.

That is, consider the possibility that the entire confusion is a deliberate policy decision.

Sunil · Post by **Sunil** » 04 Jul 2002 22:40

> the uncertainity in the value of `a' is because of secrecy.

Not exactly, there will be a statistical aspect to the measurements used to determine `a' on site. We assume that this statistical aspect will be very small as compared to the difference between the BARC values and walter and co's `guesstimates'.

> 2. Taking the interference theory seriously, 45 kiloton and 10 kiloton explosions will not produce the interference pattern advertised because of the difference in magnitudes (think of a bright source and a dim source.)

No, this is incorrect. You can have interference between sources of differing intensities. It happens in a piano all the time. Strings struck produce notes of different intensity but harmony does not disappear.

The `explosion' regardless of size first melts a small region of earth immediately outside it. The particles outside the melting shell feel the force from the explosion.

If you set off two explosions, the particle will see the force from two explosions and will respond in an identical fashion to each.

Now the melting and vaporising occurs on a much smaller timescale than the period of the seismic wave, the particles outside the melting-vaporising shell see the forces from the two explosions simultaneously. So the motion of the particles is a sum of the wave amplitudes from each explosion.

> 3. In any case, I do not take the interference theory seriously.

This I can't really do anything about. Your lack of seriousness on this matter is not something I can reasonably be expected to change.

> Two simultaneous explosions are not akin to striking two tuning forks simultaneously ; it is similar to striking two bells simultaneously. A wide spectrum is excited and neighboring spectral components differ in phase relationships, so that summing over all components destroys interference.

Yes there will be a wide spectrum of noises. But, how precisely do you make the statement that

"A wide spectrum is excited and neighboring spectral components differ in phase relationships, so that summing over all components destroys interference."

This is not at all trivial, please give me a detailed argument as to how this dephasing occurs in the seismic frequency range. What are the mechanisms that cause such a dephasing?

> Given that you know how to go "bang" , mastery of the technology is not demonstrated by making a bigger bang - it is demonstrated by being able to meet design objectives. India cannot annouce correctly the designed for yield and actual yield without giving away once and for all, the value of "a" for Pokharan;

What makes you feel that the scaling from low yeild to high yeild is so simple? Even a glance at FBF devices tells you that the way the `bang' occurs is completely different as compared to a purely fission device.

The stated design objectives by BARC have been to demonstrate a working FBF design and to test a range of other device designs of various yeilds.

> and if the policy is to keep "a" secret, then one has to keep in mind that the announcements made by India are deliberately obfuscating.

The west can figure out a value for `a' from our data. They know our mb Values, they know our estimates of the yeild. They can find out what we think is `a'. So i still don't see what you feel is so secret about it.

If you expect the MEA-PRO to make a statement to world about it saying: " Hey world! didya know the `a' at Pokharan is ....!!!!" then forget it. No one does that. But the information that we have given out should be able to give people an inference of what we think the `a' is, if and only if they use the correct model to analyse their measurements. If they persist in using incorrect models to analyse the data, and offering counter claims of `a' and yeild, there is no room for progress.

> That is, consider the possibility that the entire confusion is a deliberate policy decision.

Credible deterrence and confusion do not go together. Creating the illusion that India's nuclear deterrent does not work, does not promote regional stability. The western approach of projecting lower yeilds is a way of getting India to release more information about its tests and to reassure Pakistan that they are not abominably far behind. That is all.

We have been crystal clear about where we stand scientifically on this issue. The same cannot be said of the Walter, Douglas et al.

Generally speaking we have been much more open about this, everyone knows that Pokharan is a testing site, no one goes around claiming that alien spaceships land there.

Sunil · Post by **Sunil** » 04 Jul 2002 23:08

Ramar Pillai has given one lecture at IIT-Chennai and other places before he was exposed.

I can think of a far higher number of western `scholars'

who have given multiple lectures at Indian institutions.

In part its what nitin talked about sometime earlier about the attitude of some Indians, "Saar-Saar you are beeg faaamus internashional paaarson saaar... can you geeve me a job saaar... i weeel ssoo totallly suck your c*ck saaar..suckeee suckeee saar mmmmmm western **** soooo goood... "...

and in part its the `friendlys' culture i talked about to Jumrao earlier on the cabinet reshuffle thread.

Some people in India seem to love believing the worst about their own government while believing everything that any random idiot in the west has to say. What can one be expected to do about such a people....

There is really no answer to the "India-bad-poor-evil, Indian-politishaian-uneducated-foolish-corrupt and Wesht-great-smart-coooooool-gooooooooood-reeech, India should be more like Weshtern country--- India is not doing what it takes to become wesshtern country... so Bad India Bad India.. ' philosophy.

Kuttan · Post by **Kuttan** » 04 Jul 2002 23:35

Hey guys:

Although "a" may be unknown, the RELATIVE yields of the several explosions must be independent of the choice of "a". If you find "a" by matching a seismic measurement with ONE of the officially-announced yields, what do you get for the others? This test would at least tell you whether the formula describes the yield IF the correct value of a is known.

A_Gupta · Post by **A_Gupta** » 05 Jul 2002 02:05

I haven't seen any discussion on why India would test three devices at the same time. What does one learn from the point of science or engineering by simultaneous nuclear tests ?

I can think of only one engineering reason. If one has a limited area in which one can do tests, and one wants to do multiple tests rapidly, then the first test might damage the set-up for the second test, and so one would do the tests simultaneously. Against this one must weigh the disadvantages of having to disentangle the effects of two tests on one's instruments; and if the first test could damage the set-up for the second, then if the second does not succeed, its set-up may be lost - why would one take the risk ?

So, discounting this scenario, the only reason for doing tests simultaneously would be concealment and deception. One might try to hide the signature of a smaller, more significant event in that of a larger one (though what this might be, I do not know.) Or one may want to hide one's capabilities.

Of course, it is possible that the (rather expensive ? ) tests were not done optimized for gathering engineering data, but rather for political effect; but it beats me how three bombs of yields over a range of magnitude is more effective than one.

-Arun Gupta

Calvin · Post by **Calvin** » 05 Jul 2002 02:09

A_Gupta: It might be wise to learn a little bit about the physics before spouting off. The BRM article is fairly clear about the physics of interference of stationary waves.

Secondly, regardless of the reasoning behind simultaneous detonations (cf: Chengappa - "WOP" p.425), the fact remains that it has an impact on the analysis of the readings.

Calvin · Post by **Calvin** » 05 Jul 2002 02:17

Here is Carey Sublette's article.

http://nuketesting.enviroweb.org/hew/India/IndiaRealYields.html

Impact on surface features of depth and magnitude of detonation

http://nuketesting.enviroweb.org/hew/Library/Effects/CraterDiag2_640.gif

http://nuketesting.enviroweb.org/hew/Library/Effects/Craters1024c30.jpg

A_Gupta · Post by **A_Gupta** » 05 Jul 2002 02:25

Calvin, alas, my years of a physics Ph.D. at Caltech have gone to waste - I'm doing telecom software now ! - but I don't think I'm utterly clueless.

Yes, there could be directional effects from two nuclear blasts, but my guess would be that this would be from interaction of the shock waves from the two explosions at the test site. Wave interference as postulated in the BRM paper is a linear effect, my guess would be a non-linear interaction of shock waves near the explosion.

Please note, I'm not contradicting the main thrust of this thread - that there is simply not enough information available to reliably estimate the yield of Pokharan I & II from seismology.

Sunil · Post by **Sunil** » 05 Jul 2002 02:49

A_Gupta,

> why multiple explosions

The reasons given were those of time and space, both were heavily constrained.

> Please note, I'm not contradicting the main thrust of this thread - that there is simply not enough information available to reliably estimate the yield of Pokharan I & II from seismology.

I don't think that is the main thrust of this thread.

The seismic measurements of Pok I and Pok II are capable of predicting yeilds within certain error bounds. The current discussion deals with the different physics models used by Indian and western scientists to analyse the data.

It is the assertion of this thread that Walter etc.. have not properly accounted for interference effects in their analysis.

So far I do not understand how you make the following assertion:

"Neighboring spectral components differ in phase relationships, so that summing over all components destroys interference."

After that in your last post you have asserted:

" Wave interference as postulated in the BRM paper is a linear effect, my guess would be a non-linear interaction of shock waves near the explosion."

I do not follow why you feel that the "wave interaction" from the two blasts would not be a linear superposition of the two waves. My point about the force from two explosions was a dynamical argument not a directional one.

Over a very short timescale in the region immediately surrounding the explosive charge there are likely to be non-linear effects. However after that time period is over, the rest of the media beyond the melting rock would only see a regular pressure wave in the seismic frequency range. The amplitudes of these waves at a distant seismic station should add linearly.

This is very much the basic premise of the thread and the article, i would really like to know why you disagree with this.

A_Gupta · Post by **A_Gupta** » 05 Jul 2002 03:25

Here is an interesting paper :

http://gawain.membrane.com/hew/India/IndiaRealYields.html

which presumably some of you have seen before.

and

http://www.iisc.ernet.in/currsci/nov102000/1359.pdf

Postscript :

Also see

http://www.fas.org/nuke/guide/india/nuke/981100-barc.htm

where Sikka et. al. use the scaling argument

(POKII is 4.45 times POKI and POKI is 13 kt):

It is well known that although there is lot of uncertainity in the determination of absolute yield from seismic data alone, the relative yield between two tests can be evaluated with a much higher confidence by use of the difference in body wave magnitudes,

D mb @ C2 log (Y1/Y2) (1)

where Y1 and Y2 are the yields of the two explosions and C2 = 0.75 to 0.8. Fig.4 gives a comparison of the seismic wave forms for the 1974 and 1998 Indian explosions as recorded at GBA. The ratio of the amplitudes of the P waves is 4.5. A similar difference is indicated by the common seismic stations for these explosions as shown in Table 1. After making necessary corrections for the source geometry of 1998 Indian explosions, an average D mb » 0.5 is obtained. This, using equation (1), leads to a yield ratio of 4.45 between 1974 and 1998 explosions is obtained, almost the same as reported by Sikka and Kakodkar (1). Taking the yield as 12 to 13 kt for the 1974 explosion, the yield of May 11 explosions is obtained as 53-58 kt.

Jash · Post by **Jash** » 05 Jul 2002 03:54

Folks there is no need to waste time and energy in this argument, I will believe our scientist and gov. than foreign spinmasters, off course most practical way to know will be when it will explode in Islamabad, Karachi and Lahor.

A_Gupta · Post by **A_Gupta** » 05 Jul 2002 04:16

After reading Sikka, et. al., and assuming that the data is not mis-stated, there is a big discrepancy between the yields as estimated from local and regional data and those estimated from long-distance seismic data; with the local data providing more accurate results (IN MY OPINION).

Now, people on various sides of the CTBT issue would be dismayed or gleeful at the seeming unreliability of monitoring via remote seismic stations. The need to show that Indian tests were correctly revealed or not by the remote seismic measurements might depend on the investigator's political position on the CTBT. Might it be possible to find out where the various authors stand on this ? (i.e., "My network of seismic stations functioned correctly, it is the Indians who are lying...")

shiv · Post by **shiv** » 05 Jul 2002 06:00

Originally posted by A_Gupta:
"My network of seismic stations functioned correctly, it is the Indians who are lying...")

Gupta, whatever technical quibbles anyone may have with you, you have come very close to one of the points that I have been trying to make.

There is an agenda beyond mere yield estimation that may make some parties bias their estimate in particular directions. But if those "parties" fill up available literature with biased data based on their clout or influence, and the same "data" has a bearing on issues other than what is important to the party that is generating and propagating biased data, then we are seeing a propagation of misinformation - even lies.

One simple lie that is being insidiously propagated to the public, dork media and even unrelated technical circles that seismology is infallibly accurate in detecting and estimating nuclear yields. There may come a time when this statement becomes true. That time is not yet here. But there are very strong forces trying to ensure that this fact is covered up.

I have other, less technical hang ups, which I will gradually "reveal" because I feel like doing so.

shiv · Post by **shiv** » 05 Jul 2002 06:02

Originally posted by A_Gupta:
Here is an interesting paper :

These are all linked from my first post.

But here are some observations about Pokhran 1974

Wallace is quoted in the Douglas paper as saying POK 1974 was 10-15 kt in ref (Wallace, T. C., Seismol. Res. Letts., 1998, 69, 386-393.)

In 1998 he changes that to 4-6 kt based on back calculation from what he calculates as the 1998 yields. He also says 1974 mb was 4.9
http://www.geo.arizona.edu/geophysics/faculty/wallace/ind.pak/

The 1974 yields have been reported variously from 2 to 20 kt.

Checking the sublette paper: http://nuketesting.enviroweb.org/hew/India/IndiaRealYields.html
1)Perkovich is quoted as saying 12-15kt for 1974
2)Quotes Ramanna and Chidambaram from 1975 as saying 12 kt
3)Iyengar as saying 8-10 kt

The FAS paper has a table listing Gupta and Pabian estimating mb in 1974 as 5 and Yield as 12 kt, and another table listing 1974 as 4-6 kt
http://www.fas.org/nuke/guide/india/nuke/

This teleseismological infighting is ridiculous - and what's worse - I'm trying to join in.

Having said that I have knowledge (but not understanding) of a mathematical way (complexity beyond my understanding) to show that what Sikka et al say are consistent with what Douglas and Wallace have said AND with the yield of 1998 May 11 coming to about 58 kt.

Kuttan · Post by **Kuttan** » 05 Jul 2002 07:07

This thread reminds me of my contemporary (nickname "Tool") who decided to apply the deep knowledge which we were taught in the PLT (that's "Physics Lecture Thread", not Pakistan Lashkar-e-Toiba) by the Mullah Dr. Sw********an. He (I mean Tool) bought a double-holder and put a 60-watt bulb and a 40-watt bulb together in order to get a 20-watt bulb. As I recall the fuse blew on the whole floor - so that must have been the seismic wave interference reaching the fuse box.

vkrishna · Post by **vkrishna** » 05 Jul 2002 07:12

A_Gupta,
I dont quite understand the reason why you believe that there is no interference in this situation. Your statement about "spectral components with different phase relationships which cancel out" is essentially a restatement of your earlier statement that the sources are incoherent (incoherent sources are those whose "spectral components" essentially have a random phase relationship which disappears on averaging). It seems to me that there would be interference if two explosions were simultaneously set off. As far as non linear effects are concerned, I dont know much about them, but I would expect that at long distances, the wave equations would be essentially linear-and memory of the initial conditions to a great extent would be lost. (At least this is what I would conclude at first sight).

JE Menon · Post by **JE Menon** » 05 Jul 2002 10:16

Here is the 1st para of Sublette's paper:

>>There is a curious anomaly that has dogged all of the nuclear tests in South Asia (including Pakistan) since the first Indian test in 1974. The reported yields of these tests have consistently exceeded the yields as estimated by the data available to outside observers.

Can somebody explain to me where the anomaly is here? It is no one's claim that all the data available to nuclear testers in South Asia (including Pakistan

, just in case someone thought otherwise) is available to outside observers. It follows, therefore, that the one with more data on an event is likely to generate results different from the one with less. Therefore, where is the "curious anomaly"?

shiv · Post by **shiv** » 05 Jul 2002 10:39

Originally posted by JE Menon:
Here is the 1st para of Sublette's paper:

Can somebody explain to me where the anomaly is here? It is no one's claim that all the data available to nuclear testers in South Asia (including Pakistan , just in case someone thought otherwise) is available to outside observers. It follows, therefore, that the one with more data on an event is likely to generate results different from the one with less. Therefore, where is the "curious anomaly"?

Doctor: "Looks like your blood pressure is more than a little high"

Patient: "No it isn't"

D: "Well, my readings say that your pressure has averaged 210 over 120 when normal presssures should not really exceed 140 over 90 for a person your age.

P:"That is not what the data available to me says"

D:"But damage is being done. Your eyes show serious changes that could lead to blindness and the blood tests show that there is some kidney damage as well"

P: "Mister, There is a curious anomaly here. I can see perfectly well, and there is nothing wrong with my kidneys."

... etc

whatmeworry

kgoan · Post by **kgoan** » 05 Jul 2002 11:21

Why did the US Senate refuse to ratify the CTBT?

Is it:

A. Because they're all a crazy bunch of war-mongering nuke-lovers.
B. Because long distance seismic monitoring is like trying to smell farts in a strong breeze.
C. Because of the military-industrial complex which is part of a conspiracy to destroy the world with nukes.
D. Because some senators just slept in that day.
E. How the duck would we know?

My guess is "B". But you may differ.

Kaushal · Post by **Kaushal** » 05 Jul 2002 11:32

Why the US refuses to sign the CTBT ( aka shitty bitty in Bengali)

The US(esp. the right wing as exemplified by Senator Helms ) is loathe to part with any semblance of its sovereignty - in this case the freedom and option to test. This has nothing to do with detection of tests by seismological means which is an effective technique today as opposed to detecting the exact yield.

Kaushal

shiv · Post by **shiv** » 05 Jul 2002 11:47

It is curious how the language used in an ostensibly academic paper can show conscious or subconscious bias.

Let me start be asking you to have a look at this paper:

SOURCE SPECTRA, MOMENT, AND ENERGY FOR RECENT EASTERN MEDITERRANEAN EARTHQUAKES: CALIBRATION OF INTERNATIONAL MONITORING SYSTEM STATIONS
Kevin M. Mayeda, Abraham Hofstetter,* Arthur J. Rodgers, and William R. Walter
Lawrence Livermore National Laboratory and *Geophysical Institute of Israel
Sponsored by U.S. Department of Energy, Office of Nonproliferation and National Security
Office of Defense Nuclear Nonproliferation, National Nuclear Security Administration
Contract No. W-7405-ENG-48
http://www.nemre.nn.doe.gov/review2000/3-Seismic%20Source%20Characterization/03-08.pdf

What an astounding paper. Astoundingly boring that is. Purely technical. No agenda. These guys (Mayeda, Hofstetter etc) are seismologists too, presumably. This is the sort of paper one gets used to, as a scientific or technical paper.

Now let me pull out some interesting statements form "technical papers" written on the subject of nuclear yields.

The following is a quote of the first few lines of the Sublette paper:
http://nuketesting.enviroweb.org/hew/India/IndiaRealYields.html

The first Indian test - Pokhran I or "Smiling Buddha" - was originally reported by the Indian AEC (Atomic Energy Commission) Chairman Homi Sethna on the day of the test to have had a yield of between 10 and 15 kilotons. Subsequently nearly all reports described the yield as 12 kilotons, or 12 to 15 kilotons [Perkovich 1999, p. 181] (and occasionally as high as 15 to 20 kilotons, [Perkovich 1999, p. 522]). In a paper presented to the IAEA in January 1975 Ramanna and Chidambaram placed the yield at 12 kilotons. Official reports following the 1998 Shakti test series have repeated this figure, or nudged it up to 13 kilotons.

On the other hand, other reports over the years have placed the yield much lower. U.S. analysts have estimated the yield as 4 to 6 kilotons [Wallace 1998, p. 3] (or go to his on-line reprint), and Indian journalists have published reports of yields as low as 2 kilotons.

Two former chairmen of the AEC have conceded in interviews that the test yield was lower than the official 12 kt figure

I find this use of language very interesting. Note the highlighted words. In the sentences the yields are:

"originally reported" - between 10 and 15 kt
"described" - 12 kilotons, or 12 to 15
"placed" - 12 kilotons
"nudged it up" - 13 kilotons
"estimated" - 4 to 6 kt
"published" - 2 kilotons
"conceded" - lower than 12

What is interesting about this? Note that when estimates are rising, the act is a surreptitious, stealthy one of "nudging" - a word describing an act that is often used in the context of stealth or deception. OK I may be paranoid.

But "conceded"? My online dictionary reveals that the word "conceded" means "to make a clean breast of", or "acknowledge defeat".

Amazing isn't it? In the mind of the author, the act of estimating yield that is higher then the author likes is a stealthy, deceptive act, and decreasing the value is a "concession" - an acceptance of defeat - as one may expect a criminal or con man to to when cornered.

This is in a technical paper.

Now let us look at the Douglas paper:
http://www.iisc.ernet.in/~currsci/jul102001/72.pdf

Sikka et al.2 argue that many of the assumptions made
by others in estimating the yield of 980511 are incorrect
and that without the availability of ?close-in ground
motion measurements, radiochemical methods, calibration
events and hydrodynamic shock measurements? together
with ?knowledge of the surroundings of the device? any
estimates other than those by scientists involved in the test
?will be not just highly subjective but erroneous?. If Sikka
et al.1,2 have so little confidence in such methods and
we agree that yields estimated by seismological methods
are subject to large uncertainties it is not clear why they
have gone to such lengths to obtain so precise a seismo-logical
estimate of yield.

This could mean what it actually says, or it could mean "Sikka must be worried about his yields, so he goes to great lengths to refute our claims". Another "technical paper" taking potshots at people who disagree with you.

Well, let me take potshots at Wallace in return, and quote from the Sublette paper (linked above)

Wallace estimates the yield of Pokhran-I both directly from the seismic signal generated by the test (a body wave magnitude of Mb4.9), and by comparing the crater features to U.S. descriptions of crater morphology for various underground test conditions.

Well if Wallace is so cock sure of his seismic assessment of Pokhran 1974, why does he change his yield estimate by half and then try to support his seismic estimate by a "crater shape" argument that has been promptly trashed by Sublette?

Hey there is no end to this business, but is it science?

svinayak · Post by **svinayak** » 05 Jul 2002 12:04

Can somebody explain to me where the anomaly is here? It is no one's claim that all the data available to nuclear testers in South Asia (including Pakistan , just in case someone thought otherwise) is available to outside observers. It follows, therefore, that the one with more data on an event is likely to generate results different from the one with less. Therefore, where is the "curious anomaly"?

It is called a manufactured anamoly carried out for the last 30 years against India. Controversy is used to create doubt and then call all the indigenous devices crude and not at all upto the western std.

JE Menon · Post by **JE Menon** » 05 Jul 2002 12:49

My question about the "curious anomaly" was a rhetorical one, essentially to point out the fact that there is nothing anomalous - let alone curious - about the fact that different data produces different results.

Now, one could argue (I won't in this case) that there's an anomaly in the fact that the yields of one set of data "consistently exceed" that of the other. But this is not true either, at least in the case of POK II - because some external sources have confirmed or exceeded the yield estimates of Indian sources.

This suggests two possibilities: either Sublette is ignorant of these external sources in making his statement, or that he's massaging the truth to enhance a particular point of view (in other words lying). Take your pick.

JCage · Post by **JCage** » 05 Jul 2002 13:30

originally posted by Acharya:
It is called a manufactured anamoly carried out for the last 30 years against India. Controversy is used to create doubt and then call all the indigenous devices crude and not at all upto the western std.

Whats worse is the number of Indians involved in perpetuating this fraud.One of the greatest being dork in chief M.V.Ramana who rushes forward to "testify" about "scientific incompetence".Really pathetic.

Regards,
Nitin

A_Gupta · Post by **A_Gupta** » 05 Jul 2002 20:52

This paper I found on the web :
http://www.princeton.edu/~globsec/publications/pdf/3_3-4Adushkin.pdf,

"Teleseismic monitoring of underground nuclear explosions at the Nevada test site from Borovoye, Kazakhstan." by Vitaly V. Adushkina and Vadim A. Ana, Science & Global Security, 1993, Volume 3, pp.289-309

The point of the paper is that the Borovoye seismic monitoring station is an excellent seismic monitoring site with little seismic noise. With data recorded at the site and info on the many US underground nuclear tests in Nevada, and calibration is possible, and with calibration, the yield estimates are accurate to within 20%.

The point of my post here is that the equation that Shiv has made us all familiar with, looks like the following, after calibration, for Borovoye seismographs, as per the paper :

mb = 4.78 + 0.52 log Y for Y < 20 kilotons
mb = 4.13 + 1.07 log Y for 20 < Y < 150 kilotons
mb = 5.48 + 0.53 log Y for Y > 150 kilotons

If similar relationships hold between the Pokhran test site and any particular seismic station as do between the Nevada test site and Borovoye then all the estimates from teleseismography cited so far are useless. 1974 provides no basis for estimate of 1998 (not because of statistical uncertainity, but because of a piecewise parametrized calibration curve).

----

I will bet that kgoan is right, that CTBT failed ratification in the US Senate because of the inefficacy of teleseismography; and in particular because of India's May 13, 1998 tests that were not detected by most stations.

One more thing - if the Pakistanis were using well-proven Chinese designs or even Chinese-provided devices, they would have no reason to lie (or ability to manufacture a convincing lie ?) in this matter. Yet teleseismography reports them to be overstating as well.

-------

There is another very interesting fact - well, should be interesting to geophysicists - in the above cited paper.

It is noteworthy that many years of observations for the NTS-Borovoyepath detected cyclical changes in the travel time and amplitude of a P wave,with primary cycles of 10-11 and 6-7 years.15.16 We assume that thesechanges result from periodic variations in the elastic properties of the environ-ment along the trajectory of a seismic wave. In our data for 1967-1989, themaximum variation in the travel time was 0.2 seconds (approximately 0.02percent), but the maximum amplitude variation reached 100 percent. It is possible that this phenomenon isresponsible for some of the uncertainty inthe relationship between magnitude and yield

Kaushal · Post by **Kaushal** » 05 Jul 2002 21:26

The simple fact of the matter is that teleseismological methods of estimating yield are just not accurate enough within an order of magnitude, not least because these are empirical formulae based on a dash of physics and a dollop of statistics. This is not surprising since the tramsmission and attenuation of waves through various media is highly dependent on the properties of the media itself. The yields are exponentially dependent on a 'guestimated constant' - which says it all. Only BARC knows for sure based on radionuclides. The rest of the world can raise all the FUD they want it machts nichts.

My only question is if they are so sure the Indians are overestimating, why are they so worried about these bombs even if they are used. surely they pose no threat at such low yield levels except for the immediate vicinity of at most 1 mile (e.g. Hiroshima - incidentally i visited Hiroshima in 1963, even then it was completely rebuilt with no sign of any damage except for 1 structure which serves as the museum). If their argument is that even a low yield bomb can be pretty lethal, then all this brouhaha about yields is worth next to nothing, whether you are incinerated by a 5kT or a 50 kT device may only be of interest to the 72 virgins.

There is cognitive dissonance at work here (IOW - the left hand does not know what the right hand is doing apart from logical non-sequitors). Clearly these nay sayers are funded by official sources to keep up their drumbeat of sowing FUD. Eventually they hope to draw out some details from BARC in order to glean more details of the physics of the bomb. I bet they will be sorely disappointed, BARC is notorious for keeping its secrets - esp. those which need to be kept.

Unfortunately there are quislings like MV Ramana who have sold their soul for paltry lucre. Oh well, in a land of 1 billion there always bound to be some.

Kaushal

A_Gupta · Post by **A_Gupta** » 05 Jul 2002 21:41

My take :

I think that a well-intentioned lot of scientists were pushing for CTBT, and their passion for CTBT overcame their objectivity.

E.g., look at the title :

Multi-Use Seismic Stations Offer Strong Deterrent to Clandestine Nuclear Weapons Testing

and look at the statement within (NTS is the Nevada Test Site)

Prior to the DoE's disclosure, U.S. regional networks independently detected 73% (148) of all previously unannounced nuclear tests (Figure 2). These tests were listed at the time of their occurrence in the open bulletins of the networks. Since 1983, when unannounced nuclear testing resumed after a 3-year period during which all tests were announced, regional networks independently detected 89% (16 of 18) of all unannounced tests.

and

Soviet stations have detected 61% of all undeclared tests conducted at NTS since 1983.

So, these guys are fooling themselves. The Indian tests destroyed CTBT in many ways, and a lot of the papers cited in this thread are influenced by the authors' pique, IMO; and as has been pointed out by Shiv, the language used itself shows the bias.

This is very interesting to me, I had not known physical scientists to be so prey to their own biases.

--
I am not ignoring the question re: interference, but have not figured out a simple way of presenting what I think.

Sunil · Post by **Sunil** » 05 Jul 2002 21:51

Mr. Arun Gupta,

Can you please explain the following assertions you made?

" neighboring spectral components differ in phase relationships, so that summing over all components destroys interference."

and

" Wave interference as postulated in the BRM paper is a linear effect, my guess would be a non-linear interaction of shock waves near the explosion."

I am not convinced about the validity of these.

I stress these allegations hit at the core of this article, whatever the errors/problems in seismic measurements etc... those apply to both Indian and western seismologists. The difference is in the physics they have applied to their analysis. It is the focus of this thread that walter and co, have not considered interference effects and this leads them to under-estimate the yeild.

You seem to feel that Walters and Co have followed a correct approach and to that end you have advanced the aforementioned arguments.

It is a character flaw but whenever someone with a background in physics claims to have a different intuition about a physical system I devote a little more attention then I do to the usual slack jawed yokel who says "Gee Mr. Sainis, You haint gonna believe me.. but I tellya I saw a U.F.O."..

You have got my attention Sir, and I would really like something more concrete on your assertions.

saint · Post by **saint** » 05 Jul 2002 21:51

Q: Why did we do two or more devices at the same time? What was the objective / test-spec behind such testing?

[technical pl.]