Rediscovering signal complexity as a teleseismic discriminant

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Pure and Applied Geophysics

OSTI ID:960952

Anderson, Dale N ^[1]; Taylor, Steven R ^[1]

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1. Los Alamos National Laboratory

We re-examine the utility of teleseismic seismic complexity discriminants in a multivariate setting using United Kingdom array data. We measure a complexity discriminant taken on array beams by simply taking the logarithm of the ratio of the P-wave coda signal to that of the first arriving direct P wave ({beta}{sub CF}). The single station complexity discriminant shows marginal performance with shallow earthquakes having more complex signatures than those from explosions or deep earthquakes. Inclusion of secondary phases in the coda window can also degrade performance. However, performance improves markedly when two-station complexity discriminants are formed showing false alarm rates similar to those observed for network m{sub b} - M{sub s}. This suggests that multistation complexity discriminants may ameliorate some of the problems associated with m{sub b} - M{sub s} discrimination at lower magnitudes. Additionally, when complexity discriminants are combined with m{sub b} - M{sub s} there is a tendency for explosions, shallow earthquakes and deep earthquakes to form three distinct populations. Thus, complexity discriminants may follow a logic that is similar to m{sub b} - M{sub s} in terms of the separation of shallow earthquakes from nuclear explosions, although the underlying physics of the two discriminants is significantly different.

• Research Organization: Los Alamos National Laboratory (LANL)
• Sponsoring Organization: DOE
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 960952
• Report Number(s): LA-UR-08-06754; LA-UR-08-6754
• Journal Information: Pure and Applied Geophysics, Journal Name: Pure and Applied Geophysics Journal Issue: 3 Vol. 166; ISSN PAGYAV; ISSN 0033-4553
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL PROTECTION
BEAMS
DATA
EARTHQUAKES
EXPLOSIONS
INCLUSIONS
NUCLEAR EXPLOSIONS
P WAVES
PERFORMANCE
PHYSICS
SIGNALS
UNITED KINGDOM