EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Understanding explosion-related aftershocks using field experiments and physics-based simulation

Kayla Kroll, Gene Ichinose, Sean Ford, Arben Pitarka, William Walter, and Douglas Dodge
Kayla Kroll et al.
  • Lawrence Livermore National Laboratory, Atmospheric, Earth, and Energy Division, United States of America (

Previous studies have shown that explosion sources produce fewer aftershocks and that they are generally smaller in magnitude compared to aftershocks of similarly sized earthquake sources (Jarpe et al., 1994, Ford and Walter, 2010). It has also been suggested that the explosion-induced aftershocks have smaller Gutenberg-Richter b-values (Ryall and Savage, 1969, Ford and Labak, 2016) and that their rates decay faster than a typical Omori-like sequence (Gross, 1996). Recent chemical explosion experiments at the Nevada National Security Site (NNSS) were observed to generate vigorous aftershock activity and allow for further comparison between earthquake- and explosion-triggered aftershocks. Of the four recent chemical explosion experiments conducted between July 2018 and June 2019, the two largest explosions (i.e. 10-ton and 50-ton) generated hundreds to thousands of aftershocks. Preliminary analysis indicates that these aftershock sequences have similar statistical characteristics to traditional tectonically driven aftershocks in the region.


The physical mechanisms that contribute to differences in aftershock behavior following earthquake and explosion sources are poorly understood. Possible mechanisms may be related to weak material properties in the shallow subsurface that do not give rise to stress concentrations large enough to support brittle failure. Additionally, minimal changes in the shear component of the stress tensor for explosion sources may also contribute to differences in aftershock distributions. Here, we compare aftershock statistics and productivity of the explosion-related aftershocks at the NNSS site to synthetic catalogs of aftershocks triggered by explosion sources. These synthetic catalogs are built by coupling strains that result from modeling the explosion source process with the SW4 wave propagation code with the 3D physics-based earthquake simulation code, RSQSim. We compare statistical properties of the aftershock sequence (e.g. productivity, maximum aftershock magnitude, Omori decay rate) and the spatiotemporal relationship between stress changes and event locations of the synthetic and observed aftershocks to understand the primary mechanisms that control them.

Prepared by LLNL under Contract DE-AC52-07NA27344.

How to cite: Kroll, K., Ichinose, G., Ford, S., Pitarka, A., Walter, W., and Dodge, D.: Understanding explosion-related aftershocks using field experiments and physics-based simulation, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-6035,, 2020

This abstract will not be presented.