Comment on "Advanced Seismic Analyses of the Source Characteristics of the 2006 and 2009 North Korean Nuclear Tests" by J. R. Murphy, J. L. Stevens, B. C. Kohl, and T. J. Bennett

Patton, Howard J.; Pabian, Frank

doi:10.1785/0120130262

Cited by 13 publications

(4 citation statements)

References 30 publications

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“…Several other nuclear explosion models have been proposed, including Haskell (), von Seggern and Blandford (), Helmberger and Hadley (), Denny and Johnson (), and Walter and Ford (). These have different spectral shape and different depth and yield‐scaling attributes, and some concerns have been raised about the Mueller‐Murphy model (e.g., Patton & Pabian, ; Walter & Ford, ). However, the Mueller‐Murphy model remains the most comprehensively parameterized model, and as shown in the modeling here, it is very effective at representing the seismic data for reasonable parameters.…”

Section: Discussionmentioning

confidence: 99%

“…Precise relative locations for the six explosions, with uncertainties on the order of a few hundred meters, have been determined by numerous seismic differential arrival time studies (e.g., Carluccio et al, ; Gibbons et al, , ; He et al, ; Myers et al, ; Murphy et al, ; Selby, ; Wang et al, ; Wen & Long, ; Yao et al, ; Zhang & Wen, ; Zhao et al, ; Zhao, Xie, He, et al, ). Absolute locations are much more difficult to resolve, and various strategies have been used to place the suite of precise relative locations in absolute position with respect to the source region topography, locations of tunnel portals, and/or deformation features on the surface inferred from InSAR or satellite photography (e.g., Murphy et al, ; Myers et al, ; Pabian & Coblentz, ; Pabian & Hecker, ; Patton & Pabian, ; Wei, ), with recent results having less than ~0.5‐km variations. The absence of collapse craters for all events complicates the absolute location process and indicates that burial depths for most events significantly exceed what is required for containment.…”

Section: Introductionmentioning

confidence: 99%

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Yield Estimates for the Six North Korean Nuclear Tests From TeleseismicPWave Modeling and Intercorrelation ofPandPnRecordings

et al. 2019

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The yields of the six declared underground nuclear tests at the North Korean test site are estimated using high-frequency teleseismic P wave amplitude modeling and waveform equalization of short-period teleseismic P waves and regional Pn signals. Average amplitudes of the first cycle of high-frequency (>4 Hz) filtered P wave displacements for each event, adjusted for station sampling relative to the 3 September 2017 event, are modeled using Mueller-Murphy explosion source models for granite and a constant-Q attenuation operator with t* = 0.78 ± 0.03 s. The yield estimates range from 2.6 to 230 kt. Intercorrelation, a waveform equalization procedure that accounts for source function and depth-phase variations between events, is applied to large sets of filtered (>0.8 Hz) teleseismic P and regional Pn seismograms. Searching over yield and burial depth for both events gives optimal parameters by simultaneous waveform equalization of multiple stations. Using specified burial depths spanning from 430 to 710 m for all events based on estimated locations in the source topography assuming tunneling with 4% grade, along with allowing for reduction in source region velocity due to weathering, rock layering, and damage zones, gives yield estimates ranging from 1.4 to 250 kt. Comparison of predicted and observed spectral ratios of Pn phases at station MDJ establishes that these source models are reasonable. Using the preferred yield estimates from intercorrelation, W IC , a yield-calibrated relation of m bNEIC = 0.9 log 10 W IC + 4.13 is determined for the North Korean test site.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Yield Estimates for the Six North Korean Nuclear Tests From TeleseismicPWave Modeling and Intercorrelation ofPandPnRecordings

et al. 2019

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“…Saikia (2017) recently presented an analytic formulation of the time-domain far-field reduced velocity potential (RVP) that is convenient for broadband waveform modeling. There are uncertainties in the scaling behavior for the MM model (e.g., Patton & Pabian, 2014), as is true for all source models. Our results are coupled to that particular model.…”

Section: Data and Modeling Proceduresmentioning

confidence: 99%

Yield Estimate (230 kt) for a Mueller‐Murphy Model of the 3 September 2017, North Korean Nuclear Test (m_bNEIC = 6.3) From Teleseismic Broadband P Waves Assuming Extensive Near‐Source Damage

Chaves

Lay

Voytan

2018

Geophysical Research Letters

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The 3 September 2017 underground nuclear test (m bNEIC = 6.3) is the largest of six announced North Korean explosions. The event generated many P wave seismograms at global broadband seismic stations with good signal-to-noise ratio for periods less than~5 s. Instrument deconvolution provides 435 stable broadband P wave ground displacement records in the period range 0.1 to 5.0 s. These are stacked in 26 azimuth/distance windows to average path and receiver effects. Waveform stacks and average amplitude of 4-Hz ground displacements are modeled assuming a Mueller-Murphy explosion source model for a granite source medium. Nonelastic pP delays consistent with burial depths in the mountainous source topography are considered, and explosion yield and an average constant-Q attenuation operator are estimated by fitting the waveforms. For a source depth of 750 m in heavily damaged environment, the estimated yield = 230 ± 50 kt and t* = 0.78 ± 0.03 s.Plain Language Summary Seismic P wave ground motions recorded around the world for the 3 September 2017 underground nuclear test at the North Korean test site are modeled to constrain the explosion yield and the average path attenuation parameter. Broadband ground motion waveforms are modeled along with the amplitude of 4-Hz ground motions, exploring a wide range of attenuation and yield parameters along with allowing for nonelastic behavior of the P wave reflection (pP) from the free surface above the explosion, which travels down through the damage zone surrounding the explosion-produced cavity. For a source depth of 750 m, which is reasonable for location of the explosion under the mountain peak, and allowing for an extensive damage zone, the waveform modeling provides an estimated yield of 230 ± 50 kt. Yield estimates of smaller events are made based on calibration of magnitude-yield relations using this result and range from 0.5 to 17.8 kt.

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“…7 This article examines what information from the surface topography can be used to understand variations in the geologic properties that influence coupling characteristics that could inform yield estimations for clandestine tests. The geology at the test site clearly has an influence on the release of radionuclides.…”

Section: Introductionmentioning

confidence: 99%

Revised Geologic Site Characterization of the North Korean Test Site at Punggye-ri

Coblentz

Pabian

2015

Science & Global Security

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Comment on "Advanced Seismic Analyses of the Source Characteristics of the 2006 and 2009 North Korean Nuclear Tests" by J. R. Murphy, J. L. Stevens, B. C. Kohl, and T. J. Bennett

Cited by 13 publications

References 30 publications

Yield Estimates for the Six North Korean Nuclear Tests From TeleseismicPWave Modeling and Intercorrelation ofPandPnRecordings

Yield Estimates for the Six North Korean Nuclear Tests From TeleseismicPWave Modeling and Intercorrelation ofPandPnRecordings

Yield Estimate (230 kt) for a Mueller‐Murphy Model of the 3 September 2017, North Korean Nuclear Test (m_bNEIC = 6.3) From Teleseismic Broadband P Waves Assuming Extensive Near‐Source Damage

Revised Geologic Site Characterization of the North Korean Test Site at Punggye-ri

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Comment on "Advanced Seismic Analyses of the Source Characteristics of the 2006 and 2009 North Korean Nuclear Tests" by J. R. Murphy, J. L. Stevens, B. C. Kohl, and T. J. Bennett

Cited by 13 publications

References 30 publications

Yield Estimates for the Six North Korean Nuclear Tests From TeleseismicPWave Modeling and Intercorrelation ofPandPnRecordings

Yield Estimates for the Six North Korean Nuclear Tests From TeleseismicPWave Modeling and Intercorrelation ofPandPnRecordings

Yield Estimate (230 kt) for a Mueller‐Murphy Model of the 3 September 2017, North Korean Nuclear Test (mbNEIC = 6.3) From Teleseismic Broadband P Waves Assuming Extensive Near‐Source Damage

Revised Geologic Site Characterization of the North Korean Test Site at Punggye-ri

Contact Info

Product

Resources

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Yield Estimate (230 kt) for a Mueller‐Murphy Model of the 3 September 2017, North Korean Nuclear Test (m_bNEIC = 6.3) From Teleseismic Broadband P Waves Assuming Extensive Near‐Source Damage