Seismic Discrimination of the May 11, 1998 Indian Nuclear Test with Short-period Regional Data from Station NIL (Nilore, Pakistan)

Rodgers, A. J.; Walter, William R.

doi:10.1007/978-3-0348-8169-2_5

Cited by 3 publications

(5 citation statements)

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“…The station NIL was one of the few regional distance stations to record the May 11, 1998 Indian nuclear test. Previously Rodgers and Walter [2002] have demonstrated that P/S ratios discriminate this test from nearby earthquakes down to lower frequencies than usual, including the 1–2 Hz band where the new regional phase attenuation maps are available. Rodgers and Walter [2002] also showed that earthquakes to the north of NIL did not discriminate well using 1–2 Hz P/S ratio and simple one‐dimensional path corrections.…”

Section: Introductionmentioning

confidence: 89%

“…Previously Rodgers and Walter [2002] have demonstrated that P/S ratios discriminate this test from nearby earthquakes down to lower frequencies than usual, including the 1–2 Hz band where the new regional phase attenuation maps are available. Rodgers and Walter [2002] also showed that earthquakes to the north of NIL did not discriminate well using 1–2 Hz P/S ratio and simple one‐dimensional path corrections. They achieved better results using a spatial correction technique based on Bayesian kriging [e.g., Schultz et al , 1998], but this still requires reference earthquakes in the vicinity of the explosion for proper identification.…”

Section: Introductionmentioning

confidence: 89%

“…Earthquakes and explosions with closely located epicenters when recorded at the same station show clear differences in their relative P‐wave and S‐wave amplitudes at high frequencies (usually >3 Hz). These differences became apparent with the advent of widespread digital seismometry in the late 1980's and early 1990's, and have been documented by a large number of researchers at different test sites [e.g., Dysart and Pulli , 1987; Baumgardt and Young , 1990; Kim et al , 1993; Walter et al , 1995; Taylor , 1996; Hartse et al , 1997; Bottone et al , 2002; Rodgers and Walter , 2002; Kim and Richards , 2007].…”

Section: Introductionmentioning

confidence: 99%

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Improvements to regional explosion identification using attenuation models of the lithosphere

Pasyanos

Walter

2009

Geophysical Research Letters

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[1] Regional P/S amplitudes have been recognized as an effective discriminant between earthquakes and explosions. While closely spaced events generally discriminate easily, the application of this technique to broad regions has been hampered by large variations in the amplitude of phases due to the attenuation of the crust and upper mantle. Making use of a recent P-wave and S-wave attenuation model of the lithosphere, we have found that correcting the events using our amplitude methodology significantly reduces the scattering in the earthquake population. We demonstrate an application of this technique to station NIL using broadarea earthquakes and the 1998 Indian nuclear explosion using the Pn/Lg discriminant in the 1 -2 Hz passband. We find that the explosion, which is lost in the scatter of the earthquakes in the uncorrected discriminant, clearly separates by correcting for attenuation structure. We see a similar reduction in scatter and separation for the Pn/Sn and Pg/Lg discriminants. Citation: Pasyanos, M. E., and W. R.Walter (2009), Improvements to regional explosion identification using attenuation models of the lithosphere, Geophys. Res. Lett., 36, L14304,

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Section: Introductionmentioning

confidence: 89%

Section: Introductionmentioning

confidence: 89%

Section: Introductionmentioning

confidence: 99%

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Improvements to regional explosion identification using attenuation models of the lithosphere

Pasyanos

Walter

2009

Geophysical Research Letters

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“…High frequency P/S ratios (>2 Hz) for IND 980511 indicate that the disturbance is an outlier to the earthquake population defined by common regional phase-ratio discriminants, such as P n /L g and P n /S n . Interestingly, these discriminants also seem effective at frequencies as low as 0.5-2.0 Hz (Rodgers & Walter 2002).…”

Section: Indian Underground Test Of May 11 1998mentioning

confidence: 97%

“…Alternatively, various P/S ratios can be formed from the regional P phases P n , P g , and S phases S n , L g , either in common or different (cross-spectral) passbands for P and S. It may be that for a particular region a certain combination offers the most promising discriminant (Walter et al 1995, Fan et al 2002, Rodgers & Walter 2002, or a number of combinations are to be considered as part of an outlier detection strategy (Fisk et al 1996).…”

Section: Regional P/s Amplitude Ratiosmentioning

confidence: 99%

Forensic Seismology and the Comprehensive Nuclear-Test-Ban Treaty

Bowers

Selby

2009

Annu. Rev. Earth Planet. Sci.

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One application of forensic seismology is to help verify compliance with the Comprehensive Nuclear-Test-Ban Treaty. One of the challenges facing the forensic seismologist is to discriminate between the many thousands of earthquakes of potential interest each year and potential Treaty violations (underground explosions). There are four main methods: (a) ratio of bodyto surface-wave magnitudes, (b) ratio of high-frequency P to S energy, (c) model-based methods, and (d) source depth. Methods (a) and (b) have an empirical basis. The weakness of methods (a)-(c) is the lack of an equivalent elastic source for an underground explosion fired in the range of geological media found around the world. Reliable routine source-depth determination has proved difficult. However, experience gained in the past decade at identifying suspicious seismic sources suggests that although no single method works all of the time, intelligent and original application of complementary methods is usually sufficient to satisfactorily identify the source in question.

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Evaluation of the Detection Ability of New Infrasound Networks Installed by Korea Meteorological Administration

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2021

J. Korean Soc. Hazard Mitig

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The Korea Meteorological Administration (KMA) installed infrasound networks in Cheorwon and Yanggu. These networks have been operated for detecting infrasound generated from artificial explosions, such as those due to North Korea's nuclear tests, and from natural phenomena such as the volcanic eruption of Mt. Baekdu. Currently, the KMA is simultaneously performing infrasound analysis and seismic wave analysis to discriminate between natural and artificial earthquakes. To efficiently perform the discrimination and analysis of artificial earthquakes, three infrasound networks were expanded in the West Sea and northern Gyeonggi-do Gyodong-do, Paju, and Yeoncheon. In this study, 22 cases of artificial earthquake events that occurred in North Korea in January 2020 were analyzed to test the analysis capabilities of the three newly installed infrasound networks. The results of the analysis confirmed that the newly installed infrasound networks exhibited a higher infrasound detection rate than the existing Cheorwon and Yanggu infrasound networks. The Cheorwon and Yanggu observation networks are being planned for relocation and installation due to aging and poor site conditions. The use of the new infrasound network is expected to improve the detection rate and analysis accuracy with respect to artificial earthquakes. Furthermore, it is expected to enhance the detection capability of infrasound generated from various physical phenomena such as nuclear tests performed by North Korea and volcanic eruption of Mt. Baekdu.

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Seismic Discrimination of the May 11, 1998 Indian Nuclear Test with Short-period Regional Data from Station NIL (Nilore, Pakistan)

Cited by 3 publications

References 20 publications

Improvements to regional explosion identification using attenuation models of the lithosphere

Improvements to regional explosion identification using attenuation models of the lithosphere

Forensic Seismology and the Comprehensive Nuclear-Test-Ban Treaty

Evaluation of the Detection Ability of New Infrasound Networks Installed by Korea Meteorological Administration

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