11:00 AM - 1:00 PM
[SVC34-P03] Monitoring of crustal deformation in active volcanoes with GNSS Continuous Observation Reference Stations
Keywords:GNSS, GEONET, GPS Integrated Analysis, REGMOS, Crustal Deformation
Geospatial Information Authority of Japan (GSI) operates GNSS Earth Observation Network System (GEONET), which is based on about 1,300 GNSS Continuously Operating Reference Stations (GEONET CORSs) nationwide and Central Analysis Center, and monitors crustal deformation all over Japan. GEONET CORSs are located at an average intervals of about 20 km in Japan and it is possible to detect crustal deformation over a relatively wide area at each volcanoes in Japan. GSI monitors crustal deformation of about 80 active volocanoes with GNSS analysis results of GEONET and periodically submits reports based on these results to the Coordinating Committee for Prediction of Volcanic Eruption.
Since GEONET CORSs are also regarded as reference points for surveying, it is necessary to collect and transfer these data stably. These stations are mainly composed of a wired power supply and a communication line. In volcanic areas, it is often difficult to install a wired power supply and communication line. GSI has been developed Remote GNSS Monitoring System for volcanoes (REGMOS) since 1997 ,which consists of batteries, solar panels and mobile phones. This system enables the continuous GNSS observation of active volcanoes even where electricity and telecommunication services are not available. GSI has set up REGMOS flexibly in response to volcanic activities. As of January 2022, 12 REGMOS have been located at 9 volcanoes including Izu Oshima and Mt. Kirishima and are used for monitoring crustal deformation of active volcanoes.
Various institutes such as Japan Meteorological Agency (JMA) and universities have set up GNSS CORSs in active volcanoes. In order to effectively utilize the data of related organizations and monitor crustal deformation associated with volcanic activities in more detail, GSI has conducted GPS Integrated Analysis in volcanic region adding the data of GEONET CORSs to the GNSS data of other organizations such as JMA and universities. There are eight institutes exchanging GNSS data for monitoring crustal deformation of volcanic activities, including JMA, National Research Institute for Earth Science and Disaster Resilience, Hot Springs Research Institute of Kanagawa Prefecture, Disaster Prevention Research Institute, Kyoto University and Kyushu Electric Power Co., Inc. (as of January 2022).
GSI conducted GPS Integrated Analysis in volcanic region. In addition to the dual-frequency analysis equivalent to the GEONET daily solutions, it is possible to perform single-frequency analysis with modeling the ionospheric delay amount from the data of GEONET CORSs . Even if there are observation points using 1-frequency receivers, it is possible to obtain high accurate analysis results equivalent to those from dual-frequency receivers by correcting the estimated ionospheric delay amount. GEONET analysis strategy, which monitors crustal deformation nationwide, has been changed from 4th edition of the basis of ITRF2005 to the 5th edition of the basis of ITRF2014 since April 2021. Now, the analysis method of GPS Integrated Analysis in volcanic region has been modified on the basis of GEONET 5th analysis strategy. In transition of the modified version of the analysis method, past data were reanalyzed using the modified version and new analysis results were compared with old ones to confirm that there was no significant difference from the tendency and amount of fluctuations. In the modified version of GPS Integrated Analysis of the basis of GEONET 5th analysis strategy, the variation in the height component is smaller than that of former version and it can be expected to be effective in monitoring crustal deformation of volcanic activity that focuses on a slight fluctuation tendency of about 1 cm. At the 149th meeting of the Coordinating Committee for Prediction of Volcanic Eruption held in December 2021, all reports concerned with GNSS analysis results from GSI were on the basis of GEONET 5th analysis strategy. In this presentation, we will introduce the efforts of GEONET to monitor crustal deformation of volcanic activities, focusing on the topics of GPS Integrated Analysis in volcanic region and REGMOS.
Since GEONET CORSs are also regarded as reference points for surveying, it is necessary to collect and transfer these data stably. These stations are mainly composed of a wired power supply and a communication line. In volcanic areas, it is often difficult to install a wired power supply and communication line. GSI has been developed Remote GNSS Monitoring System for volcanoes (REGMOS) since 1997 ,which consists of batteries, solar panels and mobile phones. This system enables the continuous GNSS observation of active volcanoes even where electricity and telecommunication services are not available. GSI has set up REGMOS flexibly in response to volcanic activities. As of January 2022, 12 REGMOS have been located at 9 volcanoes including Izu Oshima and Mt. Kirishima and are used for monitoring crustal deformation of active volcanoes.
Various institutes such as Japan Meteorological Agency (JMA) and universities have set up GNSS CORSs in active volcanoes. In order to effectively utilize the data of related organizations and monitor crustal deformation associated with volcanic activities in more detail, GSI has conducted GPS Integrated Analysis in volcanic region adding the data of GEONET CORSs to the GNSS data of other organizations such as JMA and universities. There are eight institutes exchanging GNSS data for monitoring crustal deformation of volcanic activities, including JMA, National Research Institute for Earth Science and Disaster Resilience, Hot Springs Research Institute of Kanagawa Prefecture, Disaster Prevention Research Institute, Kyoto University and Kyushu Electric Power Co., Inc. (as of January 2022).
GSI conducted GPS Integrated Analysis in volcanic region. In addition to the dual-frequency analysis equivalent to the GEONET daily solutions, it is possible to perform single-frequency analysis with modeling the ionospheric delay amount from the data of GEONET CORSs . Even if there are observation points using 1-frequency receivers, it is possible to obtain high accurate analysis results equivalent to those from dual-frequency receivers by correcting the estimated ionospheric delay amount. GEONET analysis strategy, which monitors crustal deformation nationwide, has been changed from 4th edition of the basis of ITRF2005 to the 5th edition of the basis of ITRF2014 since April 2021. Now, the analysis method of GPS Integrated Analysis in volcanic region has been modified on the basis of GEONET 5th analysis strategy. In transition of the modified version of the analysis method, past data were reanalyzed using the modified version and new analysis results were compared with old ones to confirm that there was no significant difference from the tendency and amount of fluctuations. In the modified version of GPS Integrated Analysis of the basis of GEONET 5th analysis strategy, the variation in the height component is smaller than that of former version and it can be expected to be effective in monitoring crustal deformation of volcanic activity that focuses on a slight fluctuation tendency of about 1 cm. At the 149th meeting of the Coordinating Committee for Prediction of Volcanic Eruption held in December 2021, all reports concerned with GNSS analysis results from GSI were on the basis of GEONET 5th analysis strategy. In this presentation, we will introduce the efforts of GEONET to monitor crustal deformation of volcanic activities, focusing on the topics of GPS Integrated Analysis in volcanic region and REGMOS.