[M-IS04] Interdisciplinary studies on pre-earthquake processes

[MIS04-P01] Research on volcanic activity detection using Himawari-8 AHI data

*北出 明嗣¹、服部 克巳^2,3,4、吉野 千恵² (1.千葉大学大学院融合理工学府、2.千葉大学大学院理学研究院、3.千葉大学環境リモートセンシング研究センター、4.千葉大学災害治療研究所)

Ground-based volcano monitoring is not possible for all active volcanoes due to topographical restrictions and cost. On the other hand, volcanic activities that cause lava eruptions or eruptions that cause significant human and economic damage are usually accompanied by an increase in surface temperature, making satellite remote sensing effective for temperature monitoring. Therefore, we have been developing algorithms to detect temperature anomalies associated with volcanic activities (especially for monitoring lava activities that cause serious damage to human lives and predicting pyroclastic flows) by spatiotemporal analysis of ground surface temperature around volcanoes using thermal infrared nighttime data on board artificial satellites. As a result, Noguchi et al. (2004) demonstrated the effectiveness of monitoring volcanic activity in the tropics1 using nighttime infrared data from the MODIS sensor onboard the Aqua/Terra satellites, and Tsutsumi et al. (2020) showed that the appearance of a lava dome on the 2011 eruption of Mt.shinmoe In a similar analysis to Tsutsumi et al. (2020) for the eruptive activity of Mt. Shinmoe in 2018, an anomalous rise in surface temperature associated with the appearance of a lava dome was detected, but the anomalous rise in surface temperature was not detected visually or by SAR data. The reason for this may be that the summit area was covered by clouds at the time of the satellite observations, which prevented observation of the ground surface. There are two possible means of measuring surface temperatures in consideration of cloud effects: using satellite-observed microwave data and increasing the frequency of observations at target locations using geostationary meteorological data to increase the number of cloud-free observations. The former is promising, but requires a large footprint, since microwaves can penetrate clouds. The latter is promising, but the footprint becomes large. The latter is affected by clouds, but the observation frequency is every 10 minutes (2.5 minutes near Japan) (in the case of Himawari No. 8-9).
Therefore, by using thermal infrared data from the Himawari-8 satellite, which has a higher temporal resolution, we conducted a research study to contribute to the detection of surface temperature anomalies associated with magma eruptions and the appearance of lava domes, and to their detection as early as possible. As a result, we were able to confirm the temperature anomaly several hours before the eruption occurred.