Archived material is restricted to Rantburg regulars and members. If you need access email fred.pruitt=at=gmail.com with your nick to be added to the members list. There is no charge to join Rantburg as a member.
#1 I'd like to see a confirmation from the Russians. They've got the closest seismic monitoring station to that test.
Posted by Raider 2013-02-13 00:55||
#2 Once again - read, DPRK-NOT-BEING-SEEN-AS-TOO-SUCCESSFUL IN CHINA'S EYE.
A DPRK collapse for ANY reason only places the PLA that much closer to the disputed Senkakus + Okinawa = JAPAN, + of course China's real focii TAIWAN. IMO any PLA campaign in a Sino-Nippon or Sino-Nippon-US shooting war would be centered by China on its mil reconquest, or in alternate a "Munich" takeover = International "giveaway", of TAIWAN.
Posted by JosephMendiola 2013-02-13 00:56||
#3 The yield Y of a nuclear explosion is given by the equation
M = a + b log Y
where a and b are empirically determined constants for the test site and M is the magnitude.
USGS recorded an M of 4.9
One report says the Russians measured 5.3
for Novaya Zemlya test site, the eqn would be
4.9 = 4.45 + 0.75 log Y
this gives a yield Y of 4.0 kt (using the USGS value)
Using the Russian measurement
5.3 = 4.45 + 0.75 log Y
gives a yield of 13.6 kt
for Nevada Test Site, it would be
4.9 = 3.92 + 0.81 log Y
this gives a Y of 16.2 kt (USGS measurement)
5.3 = 3.92 + 0.81 Log Y
which gives Y of 50 kt
Nobody has calibrated the North Korean test site and so the empirical constants can only be guessed , based on presumed geology (or chosen to give the yield you wish to claim).
You have estimates of 4 to 16 (or 13 to 50) depending on the numbers you choose and measurement used.
Posted by john frum 2013-02-13 08:18||
#4 The USGS has now upped its estimate to 5.1 (from the earlier 4.9).
This is double the energy release.
Posted by john frum 2013-02-13 09:19||
#5 So, the Iranian nuke program is further ahead than we thought huh?
Of course, if you are hiding under your desk any time your pet Secretary of State, Lurch, mentions foreign policy and nuclear weapons in the same sentence, you would want to use the low number as in "See, I told you, its just a pack of firecrackers and some stale fertilizer."
On the other hand, if you are either Bibi Netanyahu or one of the adjoining sheiks in the ME, you will want to use the high number to slap around the local nutjob rogue Iman to get approval to DO SOMETHING.
And, if you are the French, or Ban Kai-Moon, it was not a nuke..."Its just Pudge falling out of his high chair after too much Creme Broule"
Posted by Bill Clinton 2013-02-13 10:18||
#6 john frum ... thanks for those estimates. very helpful. so the comments by the Russians may have been pretty good. maybe a blast in the range of 10-20 kT. But if people keeping upping the seismic figures, it could go over 20 kT. one way or another - it's some serious bang for the buck. that weapon worked.
bill clinton ... creme boule. good one ! HAHAHA!!
Posted by Raider 2013-02-13 11:09||
#7 One thing is definitely noticeable by the way. Since N. Korea started sharing scientific information with the Iranians - its programs have moved a lot faster. The first two N. Korean nukes were not a big success ... this latest explosion definitely was. Likewise, the N. Koreans seemed to be having problems with their rockets - but now they dont. And the Iranians' space program is also moving along at high gear. Apparently whatever technical info is being shared - it is accelerating progress in both countries.
Posted by Raider 2013-02-13 11:42||
#8 Constraints on burial depth and yield of the 25 May 2009 North Korean test from hydrodynamic simulations in a granite medium
Esteban Rougier, Howard J. Patton, Earl E. Knight, Christopher R. Bradley
Geophysical Research Letters
Volume 38, Issue 16, August 2011
Yield : depth of burial (DoB) tradeoff curves (TOCs) based on seismic magnitudes of the 25 May 2009 North Korean test depend strongly on the choice of empirical cavity radius (Rc) scaling model. Ambiguities over Rc scaling, particularly at large scaled DoB (SDoB), translate into unacceptably large systematic errors on yield estimates for this test. Hydrodynamic calculations involving realistic material response models offer a viable alternative to characterize Rc scaling for a range of SDoB where limited data from past nuclear tests exist. Results of such calculations are presented for a granite medium with a material response validated by modeling four phenomenological criteria for past nuclear tests in granite (free field velocity, energy partitioning into the seismic wavefield, velocity attenuation, and measured Rc). These results unambiguously favor the Rc scaling model of Denny and Johnson (DJ91) and the TOC based on that model. Lower bounds on yield and DoB of the North Korean test are constrained by predictions of an SDoB threshold for free surface damage from 2-D simulations since no such reported damage was observed for this test. Constrained by the hydrodynamic simulations, the DJ91 model indicates the minimum yield and DoB for the 25 May 2009 North Korean test is 5.7 kilotons and 375 m.
Posted by john frum 2013-02-13 11:53||
#9 Now, some revisionism has set in. Top American scientists have questioned the accuracy of the intelligence community┬'s assessments of the tests, and its portrayal of the North┬'s nuclear engineers as bumbling amateurs. The split indicates just how difficult it can be to understand what is happening deep underground in the famously reclusive state.
Siegfried S. Hecker, a Stanford professor who previously directed the Los Alamos National Laboratory in New Mexico, and Frank V. Pabian, a senior adviser on nuclear nonproliferation at Los Alamos, reanalyzed the global measurements of the distant rumbles in North Korea and concluded that Western observers had underestimated the power of the blasts.
Their findings, published recently in the Bulletin of the Atomic Scientists, said the first test could have yielded an explosion of up to one kiloton, and the second of up to seven kilotons. In an interview, Dr. Hecker said the higher figure suggested that the North Koreans were a lot closer to being able to produce a true weapon than first thought.
┬"If they can do four,┬" he said of the North Koreans, ┬"they can do 20,┬" roughly the size of the weapon that leveled Hiroshima, Japan.
As Dr. Hecker acknowledges, the measurements are still in dispute. Nuclear experts at the Lawrence Livermore National Laboratory in California, Los Alamos┬'s longtime rival, did their own reassessments and kept to the view that the first tests were small. The intelligence divisions of those two laboratories provide the government┬'s scientific estimates of foreign nuclear threats.
┬"We haven┬'t been able to resolve the issue,┬" Dr. Hecker said.
Posted by john frum 2013-02-13 13:24||
#10 ""If they can do four," he said of the North Koreans, "they can do 20," roughly the size of the weapon that leveled Hiroshima, Japan"
that appears to be exactly what has happened in Feb, 2013.
Posted by Raider 2013-02-13 16:11||
#11 At this time there appears to be nothing stopping the Iranians from doing their own N-test except ... just a little more time, some fine-tuning of centrifuges, and some wrench work on the assembly. Given general uncertainties in estimates ... Ahmadinejad is within "spitting distance" of his goal. So the only question is - how badly does Netanyahu really want to stop him?
Posted by Raider 2013-02-13 16:18||
#12 Wat a fok of a time to have this smirking, limp dick imposter in the White House.
Posted by Besoeker 2013-02-13 16:20||