PGS: North Korean nukes
The September meeting of the Potomac Geophysical Society will be held September 17th at the Fort Myer Officers' Club in Arlington, VA in the Campaign Room. This month's talk will be: North Korean Nuclear Test of May 25 2009: Similarities and Differences With Respect to the Initial October 9, 2006 Test, by Jack Murphy (SAIC, McLean, VA).
Abstract:
On May 25, 2009 North Korea announced that it had conducted its second nuclear weapons test. As with the first test, this second explosion was well-detected by the seismic stations of the International Monitoring System (IMS), as well as numerous other international stations operated by the USGS and other organizations. The best relative seismic location for this explosion places it within 2 km of the ground truth location of the initial 2006 test in a mountainous region of northeastern North Korea. Comparisons of the seismic data recorded at common stations from these two tests indicate that the second was approximately four times larger than the first, having an estimated yield in the range from about 2 to 5 kt. While there are many similarities in the observations from the two tests, there are several notable differences. Perhaps the most surprising of these is that there were no reported detections from any of the IMS radionuclide stations. The report of a noble gas (Xe133) detection in Canada tentatively associated with the October 2006 test had led to some optimism that the more complete network of stations operating in 2009 might provide powerful detection capability with respect to clandestine underground nuclear tests. While analyses are continuing, the absence of detections from the May 2009 test has tempered that optimism to some extent. Another unusual aspect of the May 2009 test was the observation of anomalously large long-period surface waves. While the surface waves from the October 2006 were also somewhat larger than expected, the surface wave Ms magnitude value for the May 2009 test places it in the earthquake population on the Ms:Mb discriminant plot, and there has been no convincing explanation offered for this to date. Thus, despite the many years of experience with nuclear test monitoring, there continue to be unanticipated surprises that require in-depth analyses and assessments.
Reception at 6:30. Dinner at 7:30. Talk at 8:30 PM. Allow 15 minutes for security entering Ft. Myer as all civilian vehicles are searched. To ensure access to and from Fort Myer use the Hatfield Gate, open 24 hours a day. If you wish to attend dinner ($25), please make reservations with Joydeep Bhattacharyya at 703-676-4373 or via e-mail. If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Visit the PGS web site at for new meeting announcements, etc.
Abstract:
On May 25, 2009 North Korea announced that it had conducted its second nuclear weapons test. As with the first test, this second explosion was well-detected by the seismic stations of the International Monitoring System (IMS), as well as numerous other international stations operated by the USGS and other organizations. The best relative seismic location for this explosion places it within 2 km of the ground truth location of the initial 2006 test in a mountainous region of northeastern North Korea. Comparisons of the seismic data recorded at common stations from these two tests indicate that the second was approximately four times larger than the first, having an estimated yield in the range from about 2 to 5 kt. While there are many similarities in the observations from the two tests, there are several notable differences. Perhaps the most surprising of these is that there were no reported detections from any of the IMS radionuclide stations. The report of a noble gas (Xe133) detection in Canada tentatively associated with the October 2006 test had led to some optimism that the more complete network of stations operating in 2009 might provide powerful detection capability with respect to clandestine underground nuclear tests. While analyses are continuing, the absence of detections from the May 2009 test has tempered that optimism to some extent. Another unusual aspect of the May 2009 test was the observation of anomalously large long-period surface waves. While the surface waves from the October 2006 were also somewhat larger than expected, the surface wave Ms magnitude value for the May 2009 test places it in the earthquake population on the Ms:Mb discriminant plot, and there has been no convincing explanation offered for this to date. Thus, despite the many years of experience with nuclear test monitoring, there continue to be unanticipated surprises that require in-depth analyses and assessments.
Reception at 6:30. Dinner at 7:30. Talk at 8:30 PM. Allow 15 minutes for security entering Ft. Myer as all civilian vehicles are searched. To ensure access to and from Fort Myer use the Hatfield Gate, open 24 hours a day. If you wish to attend dinner ($25), please make reservations with Joydeep Bhattacharyya at 703-676-4373 or via e-mail. If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Visit the PGS web site at for new meeting announcements, etc.
Labels: earthquakes, korea, meetings, pgs
