5:15 PM - 6:45 PM
[SVC26-P01] Crustal deformation around Atosanupuri detected by ALOS-2/PALSAR-2 Interferometry.
Keywords:Atosanupuri, Crustal Deformation, SAR Interferometry, Timeseries analysis
Introduction
Atosanupuri is an active volcano located at the center of Kussharo Caldera, eastern part of Hokkaido. Along with lava domes around, it forms Atosanupuri volcano complex.
No historical eruption is recorded at Atosanupuri, however several unrest is known (National Catalogue of the active volcanoes in Japan 4th ed.). In 1993-94, about 25cm of uplift is observed by SAR Interferometry, which is considered as a magma injection event (GSI, 2006; Fujiwara et al., 2017).
This inflation event is followed by long-continuing deflation. Its spatial pattern is a mirror image of uplift pattern.
Since 2021, change of GNSS baseline length is observed. To study detailed spatial pattern of the deformation, timeseries analysis of Interferometric SAR data is carried out.
Data and Analysis
We used total of 54 scenes observed by ALOS-2/PALSAR-2, from different paths (16, 17 and 121). RINC (Ozawa et al., 2016) and GIAnT (Agram et al., 2013) are used for interferogram generation and timeseries analysis respectively. Analysis period spans between 2014 and 2023.
Result and discussion
Deformation timeseries shows continuous deflation until 2021 and inflation thereafter. Maximum line-of-sight displacement of inflation period is about 10cm. We then compared spatial pattern of the deformation of two periods, however, no significant difference is seen. Also, no significant change in deformation pattern is seen in inflation period. Thus, we consider that the geometry of the deformation remained unchanged throughout the observation period.
Summary
Based on the result stated above, we regard the deformation observed sinse 2021 as magma intrusion event quite similar to the unrest in 1993-94. Careful monitoring should be continued in case the volcanic activity shows difference from 1993-94 unrest.
Atosanupuri is an active volcano located at the center of Kussharo Caldera, eastern part of Hokkaido. Along with lava domes around, it forms Atosanupuri volcano complex.
No historical eruption is recorded at Atosanupuri, however several unrest is known (National Catalogue of the active volcanoes in Japan 4th ed.). In 1993-94, about 25cm of uplift is observed by SAR Interferometry, which is considered as a magma injection event (GSI, 2006; Fujiwara et al., 2017).
This inflation event is followed by long-continuing deflation. Its spatial pattern is a mirror image of uplift pattern.
Since 2021, change of GNSS baseline length is observed. To study detailed spatial pattern of the deformation, timeseries analysis of Interferometric SAR data is carried out.
Data and Analysis
We used total of 54 scenes observed by ALOS-2/PALSAR-2, from different paths (16, 17 and 121). RINC (Ozawa et al., 2016) and GIAnT (Agram et al., 2013) are used for interferogram generation and timeseries analysis respectively. Analysis period spans between 2014 and 2023.
Result and discussion
Deformation timeseries shows continuous deflation until 2021 and inflation thereafter. Maximum line-of-sight displacement of inflation period is about 10cm. We then compared spatial pattern of the deformation of two periods, however, no significant difference is seen. Also, no significant change in deformation pattern is seen in inflation period. Thus, we consider that the geometry of the deformation remained unchanged throughout the observation period.
Summary
Based on the result stated above, we regard the deformation observed sinse 2021 as magma intrusion event quite similar to the unrest in 1993-94. Careful monitoring should be continued in case the volcanic activity shows difference from 1993-94 unrest.