CTBT: Science and Technology Conference 2025 - SnT2025

Yield and Depth of an Explosion Inverted from Regional Seismograms with Source Complexity – Illustration of the Effectiveness Using Synthetic Seismograms

P2.2-389

Not scheduled

20m

Zeremoniensaal

E-poster T2.2 Seismoacoustic Sources in Theory and Practice P2.2 Seismoacoustic Sources in Theory and Practice

Speaker

Mr Chandan Saikia (Air Force Technical Applications Center (AFTAC))

Description

A method to estimate yield and depth of explosions when accompanied by both DC and strong CLVD contributions will be presented. This paper will point out an amplitude deficiency in the CLVD green functions (GFs) constructed using no-torque three-orthogonal force dipoles (FDP). Vertically symmetric CLVD GFs are smaller by a factor of 2 than the DC source ZDD/RDD GFs, which is not accounted in the routine waveform inversion. Explicit radiation coefficients of the FDP vs. DC sources show this discrepancy (Saikia et al., 2008) which is also observed in the numerical SW4 vs. F-K seismograms. For source functions we used the time-domain source functions for explosions and delta function for the others. We set up the partials of the simulated explosion seismograms with respect to yield and depth, including the GF partials at each depth. We modified the TDSFs (Saikia, 2017, https://doi.org/10.1093/gji/ggx072) and the F-K code (FK_PROG, Saikia and Burdick, 1991, https://doi.org/10.1029/91JB00921) to code these analytic expressions for the GFs partials only at the source layer. We validated the new partials of explosion sources as independent of the elastic radius of the explosion sources using analytical and numerical results. In this study, we present the effectiveness of the method.