Bayesian Differential Moment Tensor Inversion of Clustered Nuclear Tests
Abstract
Accurate seismic moment tensor measurement plays an important role in nuclear test monitoring and yield estimation. However, conventional source moment tensor inversions require accurate Greens functions between source and receivers, and rely mostly on regional data coverage which could be sparse or incomplete in azimuthal coverage. In this study, we propose a new method, differential moment tensor inversion (diffMT), which adopts relative measurements to remove the path effects shared by different events at the same station, thereby improving the accuracy of source parameter determination. We apply diffMT to the four nuclear tests conducted by North Korea from 2009 to 2016. We found that, compared with the traditional method of waveform-based moment tensor inversion, diffMT more tightly constrains the moment tensor components of these nuclear tests, measures the energy release of these events more accurately, and better distinguishes their isotropic and tectonic release components. Our results provide potential insights on the explosion mechanisms and physical processes of North Korea's nuclear tests.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 30, 2020
- Accession Number
- AD1124660
Entities
People
- Donald V. Helmberger
- Zhe Jia
- Zhongwen Zhan
Organizations
- California Institute of Technology