Quadratic negative evidence discrimination

Technical Report · Thu May 01 04:00:00 EDT 1997

DOI:https://doi.org/10.2172/549314· OSTI ID:549314

Anderson, D N; Redgate, T; Anderson, K K; Rohay, A C; Ryan, F M

This paper develops regional discrimination methods which use information inherent in phase magnitudes that are unmeasurable due to small amplitudes and/or high noise levels. The methods are enhancements to teleseismic techniques proposed by, and are extended to regional discrimination. Events observed at teleseismic distances are effectively identified with the M{sub s} vs m{sub b} discriminant because relative to the pressure wave energy (m{sub b}) of an event, an earthquake generates more shear wave energy (M{sub s}) than does an explosion. For some teleseismic events, the M{sub s} magnitude is difficult to measure and is known only to be below a threshold . With M{sub s} unmeasurable, the M{sub s} vs m{sub b} discriminant cannot be formed. However, if the M{sub s} is sufficiently small relative to a measured m{sub b}, then the event is still likely to be an explosion. The methods presented in this report are developed for a single seismic station, and make use of empirical evidence in the regional L{sub g} vs p{sub g} discriminant. The L{sub g} vs p{sub g} discriminant is analogous to the teleseismic M{sub s} vs m{sub b} discriminant.

• Research Organization: Pacific Northwest National Lab., Richland, WA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 549314
• Report Number(s): PNNL--11579; ON: DE97053521; BR: GC0402000
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
EARTHQUAKES
EXPLOSIONS
MEASURING METHODS
SEISMIC EVENTS
SEISMIC NOISE
SEISMIC WAVES
STATISTICS