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Source analysis of the Memorial Day explosion, Kimchaek, North Korea
Author(s) -
Ford Sean R.,
Dreger Douglas S.,
Walter William R.
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl040003
Subject(s) - explosive material , seismology , geology , seismic moment , moment (physics) , waveform , moment tensor , magnitude (astronomy) , scalar (mathematics) , isotropy , moment magnitude scale , seismic wave , displacement (psychology) , geodesy , physics , mathematics , geometry , optics , fault (geology) , psychology , chemistry , deformation (meteorology) , oceanography , organic chemistry , classical mechanics , quantum mechanics , voltage , astronomy , scaling , psychotherapist
A series of source inversions are performed for the 25 May 2009 (Memorial Day) North Korean seismic event using intermediate period (10–50 s) complete waveform modeling. An earthquake source is inconsistent with the data and the best‐fit full seismic moment tensor is dominantly explosive (∼60%) with a moment magnitude (M W ) of 4.5. A pure explosion solution yields a scalar seismic moment of 1.8 × 10 22 dyne‐cm (M W 4.1) and fits the data almost as well as the full solution. The difference between the full and explosion solutions is the predicted fit to observed tangential displacement, which requires some type of non‐isotropic (non‐explosive) radiation. Possible causes of the tangential displacement are additional tectonic sources, tensile failure at depth, and anisotropic wave propagation. Similar displacements may be hidden in the noise of the 2006 event. Future analyses of this type could be used to identify and characterize non‐earthquake events such as explosions and mine collapses.