5:15 PM - 6:45 PM
[SVC26-P12] Deformations Detected by Precise Levelling and GNSS Campaign Surveys in the Hakone volcano (2015-2023)
Keywords:Hakone Volcano, Precise Leveling Survey, GNSS, Deformation
The precise leveling and the GNSS campaign surveys were conducted due to discuss the deformations in the Hakone volcano in the period from 2015 to 2021.
The leveling routes of about 11 km with 41 benchmarks were established on the northern flank of central cone of Hakone volcano in 2015. The main route was extended from GEONET Hakone (Ninodaira) to the Togendai ropeway station. In order to improve the spatial layout of the benchmarks, a branched leveling route extended to Owakudani was established. We conducted the precise leveling surveys in December 2015, September 2016, December 2017, December 2018, December 2019, December 2020, December 2021 and December 2023.
The GNSS campaign surveys were conducted on the four observation points around the leveling route in December 2017, December 2018, December 2019, December 2020, December 2021 and December 2023. Deformations of not only the four campaign sites but also continuous GNSS station (GEONET Hakone) were calculated using the RTKLIB (Takasu et al.,2007).
In the period of December 2021- December 2023, the subsidence of 12mm was detected with respect to the GEONET Hakone on the Owakudani, and the small uplift of 3mm was detected around the junction of Owakudani.
As the total deformaion in the period between December 2015 and December 2021, the subsidence of 76mm and the uplift of 15mm were detected in the Owakludani and the junction of Owakudani, respectively.
Since GEONET Hakone is too close to accept as a reference point for the vertical deformation in Hakone volcano, we used GEONET Atsugi as the reference point. The GEONET Hakone showed the uplift of 7mm with respect to the GEONET Atsugi in the period from December 2021 to December 2023. Therefore, the uplift of 10mm was detected with respect to the GEONET Atsugi around the junction of Owakudani in this period.
In the period from December 2021 to December 2023, slight increases of seismic activity were observed in December 2021, March 2023 and October 2023.
A In the junction of Owakudani, horizontal deformation of 8mm with East-Southeast direction was calculated with respect to the GEONET Atsugi in the period of 2017-2020. In other stations, no significant deformations over 5mm were detected.
Acknowledgement: This work was supported by the 2023 Hakone-Geopark Grant.
The leveling routes of about 11 km with 41 benchmarks were established on the northern flank of central cone of Hakone volcano in 2015. The main route was extended from GEONET Hakone (Ninodaira) to the Togendai ropeway station. In order to improve the spatial layout of the benchmarks, a branched leveling route extended to Owakudani was established. We conducted the precise leveling surveys in December 2015, September 2016, December 2017, December 2018, December 2019, December 2020, December 2021 and December 2023.
The GNSS campaign surveys were conducted on the four observation points around the leveling route in December 2017, December 2018, December 2019, December 2020, December 2021 and December 2023. Deformations of not only the four campaign sites but also continuous GNSS station (GEONET Hakone) were calculated using the RTKLIB (Takasu et al.,2007).
In the period of December 2021- December 2023, the subsidence of 12mm was detected with respect to the GEONET Hakone on the Owakudani, and the small uplift of 3mm was detected around the junction of Owakudani.
As the total deformaion in the period between December 2015 and December 2021, the subsidence of 76mm and the uplift of 15mm were detected in the Owakludani and the junction of Owakudani, respectively.
Since GEONET Hakone is too close to accept as a reference point for the vertical deformation in Hakone volcano, we used GEONET Atsugi as the reference point. The GEONET Hakone showed the uplift of 7mm with respect to the GEONET Atsugi in the period from December 2021 to December 2023. Therefore, the uplift of 10mm was detected with respect to the GEONET Atsugi around the junction of Owakudani in this period.
In the period from December 2021 to December 2023, slight increases of seismic activity were observed in December 2021, March 2023 and October 2023.
A In the junction of Owakudani, horizontal deformation of 8mm with East-Southeast direction was calculated with respect to the GEONET Atsugi in the period of 2017-2020. In other stations, no significant deformations over 5mm were detected.
Acknowledgement: This work was supported by the 2023 Hakone-Geopark Grant.