Absolute gravity values measured at Harutayama Observatory, Sakurajima Volcano from 2010 to 2011

Two TXT files contain the absolute gravity values measured by the FG5-210 absolute gravimeter at Harutayama Observatory, Sakurajima Volcano, Western Japan from 2010 to 2011. In each file, the 1st and 2nd columns show the year and day (in UTC), respectively, when the gravity value was measured. The 3rd and 4th columns show the reference and residual gravity values, respectively, so the sum of the 3rd and 4th columns gives the measured absolute gravity value, which is the so-called "set gravity" value in the g9 software. The 5th column shows the standard error, which was calculated by dividing the standard deviation by the number of "drop gravity". The 6th column shows the number of "drop gravity" for each set of gravity measurements.

The gravity data were used to discuss the hydrological gravity change at Sakurajima Volcano (Kazama et al., 2014). Kazama et al. (2014) showed the absolute gravity values at 0 cm height from the basement surface in Harutayama Observatory. In contrast, the TXT files in this repository show the absolute gravity values at 130 cm above the basement surface, so you can estimate the absolute gravity value just on the basement surface by adding 3.937 * 130 = 511.81 microGal to the absolute gravity value in the TXT files.