| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
SYSTEMS, SCIENCE AND SOFTWARE, P.O. BOX 1620, LA JOLLA, CALIFORNIA 92038
Abstract
Anomalous surface wave observations from underground explosions have been widely attributed to the phenomenon of spall, i.e., the detachment and subsequent slapdown of near-surface layers in response to explosion-induced tensile stresses. We argue, on the basis of a simple equivalent-force model, that, while spall can enhance explosion surface waves at very short periods, it cannot contribute significantly to the teleseismic surface waves radiated by underground explosions at periods exceeding about 10 sec. Previous theoretical results to the contrary are in error, having been based on source models which do not conserve momentum.
A nonlinear, two-dimensional (axisymmetric) finite difference simulation of a buried explosion in granite further supports the conclusion that spall cannot contribute to long-period surface waves. The simulation exhibits extensive spall; nonetheless, predicted fundamental mode Rayleigh wave spectra are nearly identical to those obtained from a spherically symmetric simulation (which does not include spall), at periods exceeding about 10 sec. At shorter periods, the two-dimensional simulation predicts some Rayleigh wave enhancement, compared to the one-dimensional simulation. The maximum enhancement, about a factor of 2, occurs at a period of approximately 2.5 sec. Synthetic long-period Rayleigh wave seismograms, at 3000 km range, show no perceptible phase or amplitude anomalies due to spall. These results are in excellent agreement with the predictions of our equivalent-force model.
This article has been cited by other articles:
|
|
 |
|
  M. Yamada, J. Mori, and T. Heaton The Slapdown Phase in High-acceleration Records of Large Earthquakes Seismological Research Letters, July 1, 2009; 80(4): 559 - 564. [Full Text] [PDF]
|
|
|
|
 |
|
 R.-M. Zhou and B. W. Stump Frequency-Domain Scaling of Single-Fired Mining Explosions with Different Confinements and Explosive Weights Detonated in Porphyry Granite Bulletin of the Seismological Society of America, December 1, 2007; 97(6): 1862 - 1879. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X. Yang, B. W. Stump, and W. Scott Phillips Source mechanism of an explosively induced mine collapse Bulletin of the Seismological Society of America, June 1, 1998; 88(3): 843 - 854. [Abstract] [PDF]
|
|
|
|
|
|
J. Zhang Source characterization using simplified waveforms: Tests on earthquakes and nuclear explosions in Xinjiang, China Bulletin of the Seismological Society of America, August 1, 1997; 87(4): 832 - 846. [Abstract] [PDF]
|
|
|
|
|
|
B. B. Woods and D. V. Helmberger Regional seismic discriminants using wave-train energy ratios Bulletin of the Seismological Society of America, June 1, 1997; 87(3): 589 - 605. [Abstract] [PDF]
|
|
|
|
|
|
C. A. Langston Anatomy of regional phases and source characterization of the Soviet Joint Verification Experiment, underground nuclear explosion Bulletin of the Seismological Society of America, October 1, 1995; 85(5): 1416 - 1431. [Abstract] [PDF]
|
|
|
|
|
|
H. J. Patton and S. R. Taylor Analysis of Lg spectral ratios from NTS explosions: Implications for the source mechanisms of spall and the generation of Lg waves Bulletin of the Seismological Society of America, February 1, 1995; 85(1): 220 - 236. [Abstract] [PDF]
|
|
|
|
|
|
X.-B. Xie and T. Lay The excitation of Lg waves by explosions: A finite-difference investigation Bulletin of the Seismological Society of America, April 1, 1994; 84(2): 324 - 342. [Abstract] [PDF]
|
|
|
|
|
|
S. R. Taylor False alarms and mine seismicity: An example from the Gentry Mountain Mining Region, Utah Bulletin of the Seismological Society of America, April 1, 1994; 84(2): 350 - 358. [Abstract] [PDF]
|
|
|
|
|
|
S. R. TAYLOR, J. T. RAMBO, and R. P. SWIFT Near-source effects on regional seismograms: An analysis of the NTS explosions PERA and QUESO Bulletin of the Seismological Society of America, December 1, 1991; 81(6): 2371 - 2394. [Abstract] [PDF]
|
|
|
|
|
|
S. M. DAY and K. L. MCLAUGHLIN Seismic source representations for spall Bulletin of the Seismological Society of America, February 1, 1991; 81(1): 191 - 201. [Abstract] [PDF]
|
|
|
|
|
|
H. J. PATTON Characterization of spall from observed strong ground motions on Pahute Mesa Bulletin of the Seismological Society of America, October 1, 1990; 80(5): 1326 - 1345. [Abstract] [PDF]
|
|
|
|
|
|
S. R. TAYLOR, N. W. SHERMAN, and M. D. DENNY Spectral discrimination between NTS explosions and Western United States earthquakes at regional distances Bulletin of the Seismological Society of America, August 1, 1988; 78(4): 1563 - 1579. [Abstract] [PDF]
|
|
|
|
|
|
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]
|
|
|
|
|
|
B. W. STUMP Mathematical representation and physical interpretation of a contained chemical explosion in alluvium Bulletin of the Seismological Society of America, August 1, 1987; 77(4): 1312 - 1325. [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]
|
|
|
|
|
|
B. W. STUMP Constraints on explosive sources with spall from near-source waveforms Bulletin of the Seismological Society of America, April 1, 1985; 75(2): 361 - 377. [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]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
