Prediction of ground motion and dynamic stress change in Baekdusan (Changbaishan) volcano caused by a North Korean nuclear explosion

Abstract

Strong ground motions induce large dynamic stress changes that may disturb the magma chamber of a volcano, thus accelerating the volcanic activity. An underground nuclear explosion test near an active volcano constitutes a direct treat to the volcano. This study examined the dynamic stress changes of the magma chamber of Baekdusan (Changbaishan) that can be induced by hypothetical North Korean nuclear explosions. Seismic waveforms for hypothetical underground nuclear explosions at North Korean test site were calculated by using an empirical Green’s function approach based on a source-spectral model of a nuclear explosion; such a technique is efficient for regions containing poorly constrained velocity structures. The peak ground motions around the volcano were estimated from empirical strong-motion attenuation curves. A hypothetical M7.0 North Korean underground nuclear explosion may produce peak ground accelerations of 0.1684 m/s2 in the horizontal direction and 0.0917 m/s2 in the vertical direction around the volcano, inducing peak dynamic stress change of 67 kPa on the volcano surface and ~120 kPa in the spherical magma chamber. North Korean underground nuclear explosions with magnitudes of 5.0–7.6 may induce overpressure in the magma chamber of several tens to hundreds of kilopascals.

Detecting remotely triggered microseismicity around Changbaishan Volcano following nuclear explosions in North Korea and large distant earthquakes around the world

“…It is worth noting that the magnitudes of UNEs (and the associated amplitudes at station CBS) increased systematically with time since 2006 (Figures and S3 and Table S2). Hence, if North Korea keeps increasing the magnitude of its future UNEs, they may have the capability of triggering volcanic activities [ Hong et al , ] and produce large enough long‐period surface waves to trigger microseismicity in this region as well.…”

“…Figure c clearly shows that dynamic stresses from long‐period surface waves (e.g., 10–60 s) for the five UNEs are at least 2–3 orders smaller than those for the large distant earthquakes that have triggered microseismicity in this region. This is consistent with the recent numerical simulation of dynamic stress changes by hypothetical M 7.0‐type UNEs detonated by North Korea [ Hong et al , ]. However, we note that the amplitudes and frequency responses of triggered earthquakes and volcanoes could be different [e.g., Manga and Brodsky , ].…”

“…Second, a magmatic unrest occurred in Changbaishan Volcano between 2002 and 2005, raising concerns for future seismic/volcanic risk in this area [ Xu et al , ]. Finally, since 2006 North Korea has detonated five Underground Nuclear Explosions (UNEs) with m b 4–5 only ~140 km away, which led to the question of whether the associated dynamic stresses are large enough to disturb magma chambers and trigger volcanic eruptions [ Hong et al , ].…”

Dynamic Triggering of Mud Volcano Eruptions During the 2016–2017 Central Italy Seismic Sequence

“…To estimate the dynamic stress generated by the passing seismic waves, we use peak ground velocity (PGV) field from the Amatrice, Norcia, and Montereale‐Capitignano‐Campotosto earthquakes, since peak ground velocity scales with the peak dynamic stress. We converted the earthquake peak ground velocities to stress using the following equation (Gomberg & Davis, ; Hill et al, ; Hong et al, ; Van Der Elst & Brodsky, ): where σ r is the radial peak dynamic stress, PGV is the peak ground velocities, β is the shear wave velocity, and μ is the shear modulus. Shear modulus μ can be derived from: where ρ is the rock density.…”

“…Passage of seismic waves generated by large earthquakes induces transient changes in stress at remote distances that can trigger local seismicity (Hill, 2008) and also enhance activity at volcanic systems (Avouris et al, To estimate the dynamic stress generated by the passing seismic waves, we use peak ground velocity (PGV) field from the Amatrice, Norcia, and Montereale-Capitignano-Campotosto earthquakes, since peak ground velocity scales with the peak dynamic stress. We converted the earthquake peak ground velocities to stress using the following equation (Gomberg & Davis, 1996;Hill et al, 1993;Hong et al, 2016;Van Der Elst & Brodsky, 2010):…”