Regional seismic observations of the 9 October 2006 underground nuclear explosion in North Korea and the influence of crustal structure on regional phases

Tae-Kyung Hong, Chang Eob Baag, Hoseon Choi, Dong Hoon Sheen

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

The crustally guided shear wave, Lg, is typically the most prominent phase of a nuclear explosion at regional distance. This Lg phase is analyzed often to discriminate a nuclear explosion from a natural earthquake. In addition, the Lg phase allows us to determine the size of the detonation. A nuclear explosion test in North Korea was conducted on 9 October 2006. The epicenter was located close to the eastern shore of the Korean Peninsula, resulting in raypaths that vary significantly according to the azimuths. In particular, rays radiated in the southern direction experience lateral variation of crustal structures at the continental margin. We examine the influence of raypaths on regional seismic phases by comparing the spectra and waveforms from different raypaths. Three natural earthquakes in North Korea are also examined to determine the raypath effect. We find that the Lg from the nuclear explosion dissipated significantly as result of energy leakage into the mantle resulting from variations in crustal thickness along the portion of the raypath traversing the western tip of the Sea of Japan (East Sea). Some of the leaked energy develops into mantle lid waves (Sn), causing a large energy increase to Sn. A similar feature is observed in the records of natural earthquakes. This feature is confirmed by seismic waveform modeling. The raypath effect also causes underestimation of magnitude. The Lg body wave magnitude, mb(Lg), is estimated to be 3.8-4.2 for records from pure continental paths and 2.6-3.4 for records from paths crossing continental margins. This result illustrates the need to consider raypath effects for the correct estimation of magnitudes of regional events, including a nuclear explosion.

Original languageEnglish
Article numberB03305
JournalJournal of Geophysical Research: Solid Earth
Volume113
Issue number3
DOIs
Publication statusPublished - 2008 Mar 4

Fingerprint

North Korea
Underground explosions
underground explosions
Nuclear explosions
nuclear explosions
nuclear explosion
crustal structure
Earthquakes
earthquakes
continental shelves
earthquake
continental margin
waveforms
Earth mantle
Lg-wave
Sea of Japan
mantle
energy
Guided electromagnetic wave propagation
Shear waves

All Science Journal Classification (ASJC) codes

  • Geochemistry and Petrology
  • Geophysics
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Atmospheric Science
  • Astronomy and Astrophysics
  • Oceanography

Cite this

@article{5e1e552607714335829a204c7fbc3635,
title = "Regional seismic observations of the 9 October 2006 underground nuclear explosion in North Korea and the influence of crustal structure on regional phases",
abstract = "The crustally guided shear wave, Lg, is typically the most prominent phase of a nuclear explosion at regional distance. This Lg phase is analyzed often to discriminate a nuclear explosion from a natural earthquake. In addition, the Lg phase allows us to determine the size of the detonation. A nuclear explosion test in North Korea was conducted on 9 October 2006. The epicenter was located close to the eastern shore of the Korean Peninsula, resulting in raypaths that vary significantly according to the azimuths. In particular, rays radiated in the southern direction experience lateral variation of crustal structures at the continental margin. We examine the influence of raypaths on regional seismic phases by comparing the spectra and waveforms from different raypaths. Three natural earthquakes in North Korea are also examined to determine the raypath effect. We find that the Lg from the nuclear explosion dissipated significantly as result of energy leakage into the mantle resulting from variations in crustal thickness along the portion of the raypath traversing the western tip of the Sea of Japan (East Sea). Some of the leaked energy develops into mantle lid waves (Sn), causing a large energy increase to Sn. A similar feature is observed in the records of natural earthquakes. This feature is confirmed by seismic waveform modeling. The raypath effect also causes underestimation of magnitude. The Lg body wave magnitude, mb(Lg), is estimated to be 3.8-4.2 for records from pure continental paths and 2.6-3.4 for records from paths crossing continental margins. This result illustrates the need to consider raypath effects for the correct estimation of magnitudes of regional events, including a nuclear explosion.",
author = "Tae-Kyung Hong and Baag, {Chang Eob} and Hoseon Choi and Sheen, {Dong Hoon}",
year = "2008",
month = "3",
day = "4",
doi = "10.1029/2007JB004950",
language = "English",
volume = "113",
journal = "Journal of Geophysical Research",
issn = "0148-0227",
publisher = "American Geophysical Union",
number = "3",

}

Regional seismic observations of the 9 October 2006 underground nuclear explosion in North Korea and the influence of crustal structure on regional phases. / Hong, Tae-Kyung; Baag, Chang Eob; Choi, Hoseon; Sheen, Dong Hoon.

In: Journal of Geophysical Research: Solid Earth, Vol. 113, No. 3, B03305, 04.03.2008.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Regional seismic observations of the 9 October 2006 underground nuclear explosion in North Korea and the influence of crustal structure on regional phases

AU - Hong, Tae-Kyung

AU - Baag, Chang Eob

AU - Choi, Hoseon

AU - Sheen, Dong Hoon

PY - 2008/3/4

Y1 - 2008/3/4

N2 - The crustally guided shear wave, Lg, is typically the most prominent phase of a nuclear explosion at regional distance. This Lg phase is analyzed often to discriminate a nuclear explosion from a natural earthquake. In addition, the Lg phase allows us to determine the size of the detonation. A nuclear explosion test in North Korea was conducted on 9 October 2006. The epicenter was located close to the eastern shore of the Korean Peninsula, resulting in raypaths that vary significantly according to the azimuths. In particular, rays radiated in the southern direction experience lateral variation of crustal structures at the continental margin. We examine the influence of raypaths on regional seismic phases by comparing the spectra and waveforms from different raypaths. Three natural earthquakes in North Korea are also examined to determine the raypath effect. We find that the Lg from the nuclear explosion dissipated significantly as result of energy leakage into the mantle resulting from variations in crustal thickness along the portion of the raypath traversing the western tip of the Sea of Japan (East Sea). Some of the leaked energy develops into mantle lid waves (Sn), causing a large energy increase to Sn. A similar feature is observed in the records of natural earthquakes. This feature is confirmed by seismic waveform modeling. The raypath effect also causes underestimation of magnitude. The Lg body wave magnitude, mb(Lg), is estimated to be 3.8-4.2 for records from pure continental paths and 2.6-3.4 for records from paths crossing continental margins. This result illustrates the need to consider raypath effects for the correct estimation of magnitudes of regional events, including a nuclear explosion.

AB - The crustally guided shear wave, Lg, is typically the most prominent phase of a nuclear explosion at regional distance. This Lg phase is analyzed often to discriminate a nuclear explosion from a natural earthquake. In addition, the Lg phase allows us to determine the size of the detonation. A nuclear explosion test in North Korea was conducted on 9 October 2006. The epicenter was located close to the eastern shore of the Korean Peninsula, resulting in raypaths that vary significantly according to the azimuths. In particular, rays radiated in the southern direction experience lateral variation of crustal structures at the continental margin. We examine the influence of raypaths on regional seismic phases by comparing the spectra and waveforms from different raypaths. Three natural earthquakes in North Korea are also examined to determine the raypath effect. We find that the Lg from the nuclear explosion dissipated significantly as result of energy leakage into the mantle resulting from variations in crustal thickness along the portion of the raypath traversing the western tip of the Sea of Japan (East Sea). Some of the leaked energy develops into mantle lid waves (Sn), causing a large energy increase to Sn. A similar feature is observed in the records of natural earthquakes. This feature is confirmed by seismic waveform modeling. The raypath effect also causes underestimation of magnitude. The Lg body wave magnitude, mb(Lg), is estimated to be 3.8-4.2 for records from pure continental paths and 2.6-3.4 for records from paths crossing continental margins. This result illustrates the need to consider raypath effects for the correct estimation of magnitudes of regional events, including a nuclear explosion.

UR - http://www.scopus.com/inward/record.url?scp=44449156346&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=44449156346&partnerID=8YFLogxK

U2 - 10.1029/2007JB004950

DO - 10.1029/2007JB004950

M3 - Article

AN - SCOPUS:44449156346

VL - 113

JO - Journal of Geophysical Research

JF - Journal of Geophysical Research

SN - 0148-0227

IS - 3

M1 - B03305

ER -