Full Moment Tensor Analysis of Nuclear Explosions in North Korea

Research Article| September 19, 2018 Full Moment Tensor Analysis of Nuclear Explosions in North Korea Celso Alvizuri; Celso Alvizuri aInstitute of Earth Sciences, University of Lausanne, 1015 Lausanne, Switzerland, celso.alvizuri@gmail.com Search for other works by this author on: GSW Google Scholar Carl Tape Carl Tape bGeophysical Institute, University of Alaska Fairbanks, 903 Koyukuk Dr., Fairbanks, Alaska 99775 U.S.A. Search for other works by this author on: GSW Google Scholar Author and Article Information Celso Alvizuri aInstitute of Earth Sciences, University of Lausanne, 1015 Lausanne, Switzerland, celso.alvizuri@gmail.com Carl Tape bGeophysical Institute, University of Alaska Fairbanks, 903 Koyukuk Dr., Fairbanks, Alaska 99775 U.S.A. Publisher: Seismological Society of America First Online: 19 Sep 2018 Online Issn: 1938-2057 Print Issn: 0895-0695 © Seismological Society of America Seismological Research Letters (2018) 89 (6): 2139–2151. https://doi.org/10.1785/0220180158 Article history First Online: 19 Sep 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Celso Alvizuri, Carl Tape; Full Moment Tensor Analysis of Nuclear Explosions in North Korea. Seismological Research Letters 2018;; 89 (6): 2139–2151. doi: https://doi.org/10.1785/0220180158 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietySeismological Research Letters Search Advanced Search ABSTRACT A seismic moment tensor is a 3×3 symmetric matrix that characterizes the far‐field radiation from a seismic source such as an earthquake or an explosion. We estimate full (unconstrained) moment tensors and their uncertainties for seven events at the North Korea nuclear test site. Six of the events were declared nuclear tests, and the remaining one, which we interpret as a cavity collapse, was an event that occurred eight minutes after the 2017 declared test. We also analyze two earthquake events that occurred to the south of the site. For each of the nine events, we perform a grid search over the 6D space of moment tensors, generating synthetic waveforms at each moment tensor grid point and then minimizing a misfit function between the observed and synthetic waveforms. We characterize the uncertainty of each inferred moment tensor in three ways: We use the variation in waveform misfit on the eigenvalue lune, we use a probability density function for moment tensor source types, and we use a confidence curve. We find that the source types (eigenvalue triples) for the nine events separate into three distinct groups, with one group for the nuclear tests, one group for the two earthquakes, and one group just for the collapse. We find that each of the six moment tensors for the declared tests is the sum of a double couple and a crack tensor, with the crack plane being nearly horizontal. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.