Determining the source characteristics of explosions near the Earth's surface

Abstract

We present a method to determine source characteristics of explosions near the Earth's surface. The technique accounts for the reduction in amplitudes as the explosion depth approaches the free surface and less energy is coupled into the ground. We apply the method to the Humming Roadrunner series of shallow explosions in New Mexico where the yields and depths are known. Knowledge of the material properties is needed for both source coupling/excitation and the free surface effect. Although there is the expected trade‐off between depth and yield, the estimated yields are close to the known values when the depth is constrained to the free surface. We then apply the method to a regionally recorded explosion in Syria. We estimate an explosive yield less than the 60 t claimed by sources in the open press. The modifications to the method allow us to apply the technique to new classes of events.

High‐Precision Relocation With the Burial Depths of the North Korean Underground Nuclear Explosions by Combining Pn and Pg Differential Traveltimes

“…Various methods, such as the spectral ratio analysis method (Murphy et al, 2010(Murphy et al, , 2013, hydrodynamic calculation method (Rougier et al, 2011) and regional waveform envelope method (Pasyanos & Ford, 2015;Pasyanos & Myers, 2018;Pasyanos et al, 2012), have been explored by different authors to determine the burial depth of an underground nuclear test. Interferometric synthetic aperture radar (InSAR) surface displacement data obtained at the NKTS could also constrain the burial depths, epicenters and yields of these six events (Wei, 2017;Myers et al, 2018;Sreejith et al, 2020;Wang et al, 2018).…”

Joint Bayesian Inference for Near‐Surface Explosion Yield and Height‐of‐Burst

“…The framework discussed here is straightforwardly extensible. Other acoustic features related to the negative phase (Schnurr et al, 2020) could be included, and other seismic features such as the coda (Pasyanos & Ford, 2015;Yoo, 2017) and surface waves (Bonner et al, 2013a;Napoli & Russell, 2018) could be incorporated to infer explosive yield at regional distance. The framework could be improved by testing the chemical-nuclear equivalence assumptions for near-surface events.…”

Yield Estimation of the August 2020 Beirut Explosion by Using Physics‐Based Propagation Simulations of Regional Infrasound

“…Our approach using a physics‐based propagation model can be extended to seismoacoustic yield estimation. Pasyanos and Ford (2015) demonstrated that joint seismic and acoustic likelihoods can substantially improve the determination of yield and depth‐of‐burial (DOB). Although our inversion was performed for a surface explosion based on K21, we can explore how different yields and depths can produce similar acoustic amplitudes based on the seismoacoustic energy partitioning (Ford et al., 2014; Pasyanos & Kim, 2019) (Text S2 in Supporting Information ).…”