A Caltech Library Service

Regional Source Parameters, Seismic Energy, and Discrimination

Helmberger, Don V. and Woods, Brad (1996) Regional Source Parameters, Seismic Energy, and Discrimination. In: Monitoring a comprehensive test ban treaty. NATO ASI series. No.303. Kluwer Academic Publishers , Boston, pp. 365-383. ISBN 9780792338116.

Full text is not posted in this repository.

Use this Persistent URL to link to this item:


We have examined broadband waveforms from a large number of NTS explosions and earthquakes throughout the southwestern United States in order to characterize seismic sources. Explosions were found to be richer in coda energy than earthquakes. Most earthquakes show relatively little long-period (T>4 sec) coda energy and tend to be richer in long-period and shear-wave energy than explosions. We have developed several seismic discriminants based on these observations and our modeling experience. One promising discriminant is the ratio of short-period vertical component, P-wavetrain energy, to long-period surface wave energy, averaged over three components. Explosions tend to have a higher ratio than do earthquakes, essentially an extension of m_b:M_s. Magnitude threshold for this discriminant is about 3.5. Another useful discriminant is based on the total broadband energy to moment ratio where explosions are distinguished by their stronger energy levels relative to their long-period amplitudes. This approach requires Green's functions, a source estimator program, and processes all events as earthquakes. For this method to be effective requires the calibration of the region using relatively large earthquakes, M>5, but does not require calibrations of explosions.

Item Type:Book Section
Additional Information:© 1996 Kluwer Academic Publishers. We thank Evelina Cui for producing this camera-ready manuscript and Dave Harkrider for his review. This research was supported by the Department of Defense as monitored by the Air Force Office of Scientific Research under contract F49620-93-1-0221. Contribution no. 5472, Division of Geological & Planetary Sciences, Caltech, Pasadena, CA.
Funding AgencyGrant Number
Department of DefenseUNSPECIFIED
Air Force Office of Scientific Research (AFOSR)F49620-93-1-0221
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Caltech Division of Geological and Planetary Sciences5472
Series Name:NATO ASI series
Issue or Number:303
Record Number:CaltechAUTHORS:20121203-091244448
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:35757
Deposited By: Tony Diaz
Deposited On:18 Dec 2012 16:55
Last Modified:03 Oct 2019 04:31

Repository Staff Only: item control page