10:45 AM - 12:15 PM
[SGD02-P02] Uplift in northern Kii Peninsula detected with InSAR
Keywords:crustal deformation, SAR, Kii peninsula, Microearthquake, Sambagawa metamorphic belt
Yoshida et al.(2011) revealed zone of uplift in norhtern Kii Peninsula on the basis of analyses of GNSS and leveling data, but the distribution of GNSS stations and leveling benchmarks is limited. Therefore, spatial resolution is also limited. Hashimoto (2020) presented the results of analyses of ALOS1/2 data, showing the existence of uplift area south of Kinokawa River in Northern Kii Peninsula.
However, the velocity field derived from InSAR does not fit well to that from GNSS, which suggests that further corrections are required. Here, using RINC, I reanalyzed all ALOS-2 images during 2014 to mid-2021 with correction of ionospheric and tropospheric delays and fitting to GNSS velocity field.
As a result, I obtained zone of uplift exceeding 5 mm/yr south of the Kinokawa River for the descending images (Figure 1). This area of LOS shortening is an ellipse of scale at ~ 30 km (EW) by 10 km (NS) and overlaps with the Sambagawa metamorphic belt in this region. An active zone of shallow microearthquakes is located close to this deformation area. These facts implies that crustal heterogeneities may affect the genesis of this deformation.
PALSAR-2 SLC data are shared among PIXEL (PALSAR Interferometry Consortium to Study our Evolving Land surface), and provided from JAXA under a cooperative research contract with PIXEL. The ownership of PALSAR-2 data belongs to JAXA. This study was supported by ERI JURP 2021-B-03 in Earthquake Research Institute, the University of Tokyo.
Figure 1. Map of deformation rate derived from stacked interferograms of P20-F2930 (Descending), P128-F670 and P127-F680 (Ascending). (a) E-W components, (b) U-D components. All rates of deformation are refered to that of GEONET site (Solid dot, Kawachi-Nagano, 950339). Positive value indicates easting and uplift, respectively. Circles are GEONET sites and painted at the same color scale as interferograms accoding to their deformation rate.
However, the velocity field derived from InSAR does not fit well to that from GNSS, which suggests that further corrections are required. Here, using RINC, I reanalyzed all ALOS-2 images during 2014 to mid-2021 with correction of ionospheric and tropospheric delays and fitting to GNSS velocity field.
As a result, I obtained zone of uplift exceeding 5 mm/yr south of the Kinokawa River for the descending images (Figure 1). This area of LOS shortening is an ellipse of scale at ~ 30 km (EW) by 10 km (NS) and overlaps with the Sambagawa metamorphic belt in this region. An active zone of shallow microearthquakes is located close to this deformation area. These facts implies that crustal heterogeneities may affect the genesis of this deformation.
PALSAR-2 SLC data are shared among PIXEL (PALSAR Interferometry Consortium to Study our Evolving Land surface), and provided from JAXA under a cooperative research contract with PIXEL. The ownership of PALSAR-2 data belongs to JAXA. This study was supported by ERI JURP 2021-B-03 in Earthquake Research Institute, the University of Tokyo.
Figure 1. Map of deformation rate derived from stacked interferograms of P20-F2930 (Descending), P128-F670 and P127-F680 (Ascending). (a) E-W components, (b) U-D components. All rates of deformation are refered to that of GEONET site (Solid dot, Kawachi-Nagano, 950339). Positive value indicates easting and uplift, respectively. Circles are GEONET sites and painted at the same color scale as interferograms accoding to their deformation rate.