GRSG Conference 2020 Presentation
Title: Ground deformation over Fukushima – an InSAR case study
Author: Jack Bestard
The Fukushima Daiichi Nuclear Power Plant, Japan, underwent a series of sequential meltdowns in 2011 related to the magnitude 9.0 earthquake and tsunami of the same year – causing the world’s second ‘Level 7’ nuclear event after Chernobyl.
Japan and the Tokyo Electrical Power Company (TEPCO) have been proactive in taking steps towards decommissioning the now hazardous site, with a clean-up timeline continuing work for another 30-40 years.
Considering the hazards within the area, we have performed a study over Fukushima to show how applicable and useful Remote Sensing techniques can be in nuclear disaster management and decommissioning, more specifically using Interferometric Synthetic Aperture Radar (InSAR).
With the ESA Sentinel-1a satellite mission’s open-access dataset, we have been able to create a historical baseline for Fukushima between October 2015 and October 2019 while generating a deformation map over the nuclear plant.
Our results clearly show the deformation effects of multiple different containment techniques used over the four-year period. In particular, an uplift signal of ~75 mm was observed around the reactor over a time-period directly coinciding with the implementation of a perimeter ice wall, constructed to mitigate groundwater leaching.
This study demonstrates the benefits of InSAR to monitor ground stability in near-real time, and across a wide area, without the need for direct interaction with such a hazardous site.