10:45 AM - 12:15 PM
[STT39-P09] InSAR Analysis-based Estimation of Crustal Deformation and Pressure Source Around the Azumayama Volcano
Keywords:Azumayama volcano, InSAR, crustal deformation, pressure source
Azumayama is one of the most active volcanoes in Fukushima Prefecture. The Volcanic Alert Level 2 has been repeatedly issued on this volcano until now, most recently from May 2019 to June 2019. It is necessary to monitor such active volcanoes.
We have been working on monitoring the crustal deformation around the Azumayama Volcano by using ALOS2/PALSAR-2 data [e.g., Arai et al., JpGU 2020]. In this study, InSAR analysis from July 2020 to September 2022 was performed. The results of the InSAR analysis were used to estimate subsurface pressure sources using the Mogi model [Mogi, 1958].
For the InSAR analysis, 13 pairs were created, including ascending right, ascending left, and the descending right observation. The atmospheric and ionospheric corrections were applied to each pair. RINC [Ozawa et al., 2016] was used for these analyses.
The resultant crustal deformations about 130 points, mostly taken every 0.1 deg in the volcanic area for each InSAR pair, were used for the pressure source estimation. We used MagCAP-V (JMA, Earthquake and Volcano Research Department, Meteorological Research Institute, 2008) for this estimation.
The result of the InSAR analysis showed that ionospheric correction did not work well for some combined pairs. These might be due to ionospheric disturbances caused by solar flares. The crustal deformation during this period was in a range of a few cm in both uplift and depression directions, although estimation from ascending left pairs indicated a little wider range.
The pressure source was estimated as depths of less than a few km within a radius of several km of the Oana crater. The change in volume of the pressure source was estimated as -2*10^5 - 7.0 *10^4 approximately [m^3].
Acknowledgement:
PALSAR data are shared by PIXEL (PALSAR Interferometry Consortium to Study our Evolving Land surface) and provided by JAXA under a joint research agreement with ERI (University of Tokyo).
MaGCAP-V (Earthquake and Volcano Research Department, Meteorological Research Institute, 2008), a software program to support analysis of crustal activity of volcanoes, is provide by the Meteorological Research Institute.