5:15 PM - 6:30 PM
[SSS05-P10] Crustal deformation observed with Tenryu-Funagira laser strainmeter
Keywords:Laser strainmeter, Slow slip
Meteorological Research Institute installed a long-baseline laser strainmeter (north-south direction, baseline length 400 m) at the Tenryu-Funagira station (34 ° 53.2'N, 137 ° 49.1' E) in Hamamatsu, Shizuoka Prefecture to detect wideband crustal movements including slow slips in the Tokai region (Katsumata et al., 2010). From March, 2017, the stabilized laser was replaced with the YAG laser (Araya et al., 2002).
It has been shown that the laser strainmeter has higher resolution than GNSS observation and has lower noise level with respect to the long-period deformation than borehole type strainmeter. It is expected as a measuring instrument that can detect not only short-term SSEs but also long-term SSEs. There have been no long-term SSEs that occurred during the period when the laser strainmeter was in operation, but some short-term SSE records have been detected.
This research examined the records of such slow slip after 2020. There was change that was thought to be due to short-term SSE near Aichi Prefecture occurred around January 2020. Change is almost consistent with the calculated from a fault model obtained by the Japan Meteorological Agency. Katsumata et al. (2020) detected a slow slip with a duration of 1 hour from the correlation analysis between the laser strainmeter recording and the borehole type strainmeter recording. No such slow slip could be detected from January 2020 record.
A slow slip with a duration of 1 hour (Katsumata et al., 2020) was detected during the SSE in January, 2019. I examined the effects of tidal changes during the event on faults modeled by JMA using the program used in Hirose et al. (2019). However, no siginificant correlation was found.
It has been shown that the laser strainmeter has higher resolution than GNSS observation and has lower noise level with respect to the long-period deformation than borehole type strainmeter. It is expected as a measuring instrument that can detect not only short-term SSEs but also long-term SSEs. There have been no long-term SSEs that occurred during the period when the laser strainmeter was in operation, but some short-term SSE records have been detected.
This research examined the records of such slow slip after 2020. There was change that was thought to be due to short-term SSE near Aichi Prefecture occurred around January 2020. Change is almost consistent with the calculated from a fault model obtained by the Japan Meteorological Agency. Katsumata et al. (2020) detected a slow slip with a duration of 1 hour from the correlation analysis between the laser strainmeter recording and the borehole type strainmeter recording. No such slow slip could be detected from January 2020 record.
A slow slip with a duration of 1 hour (Katsumata et al., 2020) was detected during the SSE in January, 2019. I examined the effects of tidal changes during the event on faults modeled by JMA using the program used in Hirose et al. (2019). However, no siginificant correlation was found.