Modeling regional seismic waves. Final report, 26 September 1991-25 September 1992
This research can be divided into two main topics: using the moment of regional Rayleigh waves and a regional magnitude based on the maximum amplitude of the shear wave train as a seismic discriminant and source retrieval from broadband regional seismograms. In section 1, we propose using the ratio of M sub L (local magnitude) to M sub O (Scalar Seismic Moment) as a regional discriminant analagous to the teleseismic discriminant using the m sub b; M sub s ratio. We applied this criterion to a data set of 299 earthquakes and 178 explosions and found that this ratio appears to be diagnostic of source type. This method does require the determination of regional crustal models and path calibrations from master events or by other means. In section 2, we develop and test a method of relocation and source characterization of small earthquakes using one modern regional station. First we model teleseismic body-waves of two events, which are used as masters. Short period depth phases, pP and sP, are used to establish the epicentral depth, and the events are relocated using calibrated stations and a mantle model derived for this region, TIP. The events moved upward by 12 and 31 kms, respectively. Secondly, these events can be used as masters in the calibration of other systems, case-based event characterizations, etc.
- Research Organization:
- California Inst. of Tech., Pasadena, CA (United States). Seismological Lab.
- OSTI ID:
- 5945543
- Report Number(s):
- AD-A-267295/4/XAB; CNN: F19628-90-K-0049
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
NUCLEAR EXPLOSION DETECTION
MATHEMATICAL MODELS
AFGHANISTAN
CALIBRATION
DEPTH
DIAGNOSTIC TECHNIQUES
EARTH CRUST
EARTH MANTLE
EARTHQUAKES
EPICENTERS
RAYLEIGH WAVES
REGIONAL ANALYSIS
SEISMIC DETECTION
SEISMIC WAVES
SEISMOGRAPHS
SEISMOLOGY
SEQUENTIAL SCANNING
SHEAR
ASIA
COUNTING TECHNIQUES
DETECTION
DEVELOPING COUNTRIES
DIMENSIONS
MEASURING INSTRUMENTS
SEISMIC ARRAYS
SEISMIC DETECTORS
SEISMIC EVENTS
SEISMIC SURFACE WAVES
450300* - Military Technology
Weaponry
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