HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) References Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by BURDICK, L. J. Articles by HELMBERGER, D. V. Search for Related Content GeoRef GeoRef Citation

Time functions appropriate for nuclear explosions

SEISMOLOGICAL LABORATORY DIVISION OF GEOLOGICAL AND PLANETARY SCIENCES CALIFORNIA INSTITUTE OF TECHNOLOGY, PASADENA, CALIFORNIA 91125

Abstract

The source-time function of megaton class nuclear explosions has been determined by modeling teleseismic short- and long-period body waves with synthetic seismograms. A simple analytic expression for the time function was used to closely match observations from both Novaya Zemlya and the U.S. test site at Amchitka. It was found that the time functions of all the events have a substantial overshoot. It was also found that, although the durations of the time functions did appear to depend on yield, the effect was very difficult to observe even in short-period records. All synthetics were computed by assuming a simple point source in a layered elastic half-space. It was not necessary to appeal to any nonlinear processes in the source region to explain the observations. Numerical calculations are presented to show that tectonic release triggered by earthquakes does not have a substantial effect on the P waves unless the long-period level of the tectonic event is as large or larger than the long-period level of the explosion. The pS wave, on the other hand, is shown to be very sensitive to even a moderate amount of tectonic release.

This article has been cited by other articles:

				H. J. PATTON Source models of the Harzer explosion from regional observations of fundamental-mode and higher mode surface waves Bulletin of the Seismological Society of America, June 1, 1988; 78(3): 1133 - 1157. [Abstract] [PDF]

				S. M. DAY, J. T. CHERRY, N. RIMER, and J. L. STEVENS Nonlinear model of tectonic release from underground explosions Bulletin of the Seismological Society of America, June 1, 1987; 77(3): 996 - 1016. [Abstract] [PDF]

				T. LAY, D. V. HELMBERGER, and D. G. HARKRIDER Source models and yield-scaling relations for underground nuclear explosions at Amchitka Island Bulletin of the Seismological Society of America, June 1, 1984; 74(3): 843 - 862. [Abstract] [PDF]

				A. DOUGLAS and J. A. HUDSON Comments on "time functions appropriate for nuclear explosions," by L. J. Burdick and D. V. Helmberger and "seismic source functions and attenuation from local and teleseismic observations of the NTS events Jorum and Handley," by D. V. Helmberger and D. M. Hadley Bulletin of the Seismological Society of America, August 1, 1983; 73(4): 1255 - 1264. [PDF]

				V. F. CORMIER The effect of attenuation on seismic body waves Bulletin of the Seismological Society of America, December 1, 1982; 72(6B): S169 - S200. [Abstract] [PDF]

				D. V. HELMBERGER and D. M. HADLEY Seismic source functions and attenuation from local and teleseismic observations of the NTS events jorum and handley Bulletin of the Seismological Society of America, February 1, 1981; 71(1): 51 - 67. [Abstract] [PDF]

				Z. A. DER and T. W. MCELFRESH Time-domain methods, the values of tp* and ts* in the short-period band and regional variations of the same across the United States Bulletin of the Seismological Society of America, June 1, 1980; 70(3): 921 - 924. [PDF]