5:15 PM - 6:45 PM
[U15-P96] Detection of distribution of deformation around surface rupture in Wakayamamachi, Suzu caused by the 2024 Noto Peninsula Earthquake and the 2023 Noto Earthquake using SAR data
Keywords:SAR, The 2024 Noto Peninsula Earthquake, 2023 Noto Earthquake, Ishikawa Prefecture, Wakayamamachi, Suzu
Introduction
On January 1, 2024, a magnitude 7.6 earthquake (The 2024 Noto Peninsula Earthquake) occurred on the Noto Peninsula.The Geospatial Information Authority of Japan (GIS) used aerial photographs to map the linear surface deformation that appeared in Wakayamamashi, Suzu, following the earthquake(GSI 2024).Using aerial photographs taken before and after the earthquake, they calculated the difference in surface elevation and noted that a 4-kilometer-long uplift zone was generated in the valley-floor plain along the Wakayama River.
Method
In this study, we used ALOS-2 data observed before and after the earthquake to determine the amount of three-dimensional variation in the vertical, east-west, and north-south directions in order to clarify the state of variation over a wider area around the uplift zone.
First, the pixel offset tracking (POT) was performed using ALOS-2 data from multiple orbits observed before and after the earthquake to calculate the amount of variation in the satellite line-of-sight direction and azimuth direction. Second, the results for multiple satellite line-of-sight directions and azimuth directions were then combined (Wright et al., 2004) to obtain the amount of variation in the vertical, east-west, and north-south directions.
Result
The analysis showed that there is an uplift of approximately 2 m in the uplift zone noted by the GSI, and that there is also an uplift to the west of the uplift zone, upstream of the uplift zone. A northward movement of about 2 m was observed on the right bank side slope (north-facing slope) of the Wakayama River, and a southward movement of about 0.5 m was observed on the left bank side slope (south-facing slope). It is possible that compression occurred from both sides across the uplift zone.
On the other hand, Sugimoto et al. 2023 conducted an InSAR analysis using ALOS-2 data observed before and after the M6.5 earthquake that occurred on May 5, 2023 (2023 Noto Earthquake, Ishikawa Prefecture), and localized dozens of points of local variation. In one of them, an uplift of several centimeters was observed at the same location as the uplift zone generated by the 2024 Noto Peninsula earthquake. We conducted a field survey of this area in June 2023 and found areas where the surface of the rice field was exposed after the field had been watered. These results show that a part of the Wakayama River uplift zone caused by the Noto Peninsula earthquake of 2024 was also slightly uplifted by the Noto district earthquake in Ishikawa Prefecture in 2023.
On January 1, 2024, a magnitude 7.6 earthquake (The 2024 Noto Peninsula Earthquake) occurred on the Noto Peninsula.The Geospatial Information Authority of Japan (GIS) used aerial photographs to map the linear surface deformation that appeared in Wakayamamashi, Suzu, following the earthquake(GSI 2024).Using aerial photographs taken before and after the earthquake, they calculated the difference in surface elevation and noted that a 4-kilometer-long uplift zone was generated in the valley-floor plain along the Wakayama River.
Method
In this study, we used ALOS-2 data observed before and after the earthquake to determine the amount of three-dimensional variation in the vertical, east-west, and north-south directions in order to clarify the state of variation over a wider area around the uplift zone.
First, the pixel offset tracking (POT) was performed using ALOS-2 data from multiple orbits observed before and after the earthquake to calculate the amount of variation in the satellite line-of-sight direction and azimuth direction. Second, the results for multiple satellite line-of-sight directions and azimuth directions were then combined (Wright et al., 2004) to obtain the amount of variation in the vertical, east-west, and north-south directions.
Result
The analysis showed that there is an uplift of approximately 2 m in the uplift zone noted by the GSI, and that there is also an uplift to the west of the uplift zone, upstream of the uplift zone. A northward movement of about 2 m was observed on the right bank side slope (north-facing slope) of the Wakayama River, and a southward movement of about 0.5 m was observed on the left bank side slope (south-facing slope). It is possible that compression occurred from both sides across the uplift zone.
On the other hand, Sugimoto et al. 2023 conducted an InSAR analysis using ALOS-2 data observed before and after the M6.5 earthquake that occurred on May 5, 2023 (2023 Noto Earthquake, Ishikawa Prefecture), and localized dozens of points of local variation. In one of them, an uplift of several centimeters was observed at the same location as the uplift zone generated by the 2024 Noto Peninsula earthquake. We conducted a field survey of this area in June 2023 and found areas where the surface of the rice field was exposed after the field had been watered. These results show that a part of the Wakayama River uplift zone caused by the Noto Peninsula earthquake of 2024 was also slightly uplifted by the Noto district earthquake in Ishikawa Prefecture in 2023.