16:30 〜 16:45
[SSS06-11] Exploring the eruption sequence of the Klyuchevskoy volcano group and Shiveluch volcano (Kamchatka) in 2022-2023 with the seismic background level (SBL) technique
キーワード：Volcano monitoring, Volcano seismology, Kamchatka
During past decades our capabilities and knowledge in monitoring volcanoes and forecasting their eruptions have greatly improved thanks to various new tools and techniques. However, successful cases of forecast come along with the tragical examples of missed eruptions, even at well monitored volcanoes. Thus, development of more reliable monitoring techniques is still one of the essential goals of volcanology.
Most often, episodes of volcanic unrest and eruptions are accompanied by a variety of seismic signals, so that seismic observations has become one of the most effective methods to monitor volcanoes. Amongst these, Seismic Background Level (SBL) monitoring has proven to be a promising new technique, successfully applied to Kirishima volcanoes, where it retrospectively allowed to identify unrest more than several months before the eruption of Shinmoe-dake and Iwo-yama in 2017-2018.
In order to estimate the potential of the SBL technique, we now apply it to seismic data recorded at the Shiveluch volcano (SV) and Klyuchevskoy volcano group (KVG) in Kamtchatka. SV is in active volcano erupting once or several times per year, sometimes simultaniously with the KVG, located 80 km north-east. KVG, one of the world's largest and most active subduction zone volcanic clusters, is under almost permanent unrest. For this work we chose several stations located in a close vicinity from the KVG and SV, and calculated SBL during the eruptive sequence of 2022-2023. From the first glance, time correlations between SBL variations and onsets of the major explosive eruptions remain elusive. Thus, in order to perform more reliable interpretation, we combine the seismological observations with the thermal anomalies detected by Himawari-8/9 and GCOM-C satellites. Overall, the preliminary results reflect the complexity of the eruption sequence, with important interactions between the volcanoes. SBL captures the long-term volcanic unrest of the KVG in 2023 with the culmination of two volcanoes erupting at the same time. This observation is additionally confirmed with detected thermal anomalies. Moreover, SBL results at the station located on the slope of SV reflected a potential inflation event of this volcano. In summary, variations in SBL signals appear like a useful new seismic observation tool, to be used in conjunction to more traditional ones, to better quantify the magnitude and significance of volcanic unrest.
Most often, episodes of volcanic unrest and eruptions are accompanied by a variety of seismic signals, so that seismic observations has become one of the most effective methods to monitor volcanoes. Amongst these, Seismic Background Level (SBL) monitoring has proven to be a promising new technique, successfully applied to Kirishima volcanoes, where it retrospectively allowed to identify unrest more than several months before the eruption of Shinmoe-dake and Iwo-yama in 2017-2018.
In order to estimate the potential of the SBL technique, we now apply it to seismic data recorded at the Shiveluch volcano (SV) and Klyuchevskoy volcano group (KVG) in Kamtchatka. SV is in active volcano erupting once or several times per year, sometimes simultaniously with the KVG, located 80 km north-east. KVG, one of the world's largest and most active subduction zone volcanic clusters, is under almost permanent unrest. For this work we chose several stations located in a close vicinity from the KVG and SV, and calculated SBL during the eruptive sequence of 2022-2023. From the first glance, time correlations between SBL variations and onsets of the major explosive eruptions remain elusive. Thus, in order to perform more reliable interpretation, we combine the seismological observations with the thermal anomalies detected by Himawari-8/9 and GCOM-C satellites. Overall, the preliminary results reflect the complexity of the eruption sequence, with important interactions between the volcanoes. SBL captures the long-term volcanic unrest of the KVG in 2023 with the culmination of two volcanoes erupting at the same time. This observation is additionally confirmed with detected thermal anomalies. Moreover, SBL results at the station located on the slope of SV reflected a potential inflation event of this volcano. In summary, variations in SBL signals appear like a useful new seismic observation tool, to be used in conjunction to more traditional ones, to better quantify the magnitude and significance of volcanic unrest.