Deciphering the Whisper of Volcanoes: Monitoring Velocity Changes at Kamchatka's Klyuchevskoy Group With Fluctuating Noise Fields ...

• Main Authors: Makus, Peter, Sens‐Schönfelder, Christoph, Illien, Luc, Walter, Thomas R., Yates, Alexander, Tilmann, Frederik
• Format: Text
• Language: unknown
• Published: Freie Universität Berlin 2023
• Subjects: seismology; volcano monitoring; machine learning; ambient noise; seismic velocity change; time varying earth structure; 500 Naturwissenschaften und Mathematik550 Geowissenschaften, Geologie550 Geowissenschaften; Kamchatka
• Online Access: https://dx.doi.org/10.17169/refubium-38744; https://refubium.fu-berlin.de/handle/fub188/39028

Volcanic inflation and deflation often precede eruptions and can lead to seismic velocity changes (dv/v $dv/v$) in the subsurface. Recently, interferometry on the coda of ambient noise‐cross‐correlation functions yielded encouraging results in detecting these changes at active volcanoes. Here, we analyze seismic data recorded at the Klyuchevskoy Volcanic Group in Kamchatka, Russia, between summer of 2015 and summer of 2016 to study signals related to volcanic activity. However, ubiquitous volcanic tremors introduce distortions in the noise wavefield that cause artifacts in the dv/v $dv/v$ estimates masking the impact of physical mechanisms. To avoid such instabilities, we propose a new technique called time‐segmented passive image interferometry. In this technique, we employ a hierarchical clustering algorithm to find periods in which the wavefield can be considered stationary. For these periods, we perform separate noise interferometry studies. To further increase the temporal resolution of our results, we ...