Japan Geoscience Union Meeting 2021

Presentation information

[J] Oral

S (Solid Earth Sciences ) » S-GD Geodesy

[S-GD01] Geodesy and Global Geodetic Observing System

Fri. Jun 4, 2021 9:00 AM - 10:30 AM Ch.22 (Zoom Room 22)

convener:Koji Matsuo(Geospatial Information Authority of Japan), Yusuke Yokota(Institute of Industrial Science, The University of Tokyo), Toshimichi Otsubo(Hitotsubashi University), Chairperson:Koji Matsuo(Geospatial Information Authority of Japan), Akihisa Hattori(The Graduate University for Advanced Studies)

10:00 AM - 10:15 AM

[SGD01-05] Gravity observations at Jang Bogo Station, Antarctica, and the scale factor calibrations of different type relative gravimeters

*Yoichi Fukuda1, Jun'ichi Okuno1, Koichiro Doi1, Choon-ki Lee2 (1.National Institute of Polar Research, 2.Korea Polar Research Institute)

Keywords:Absolute gravimeter, Superconducting gravimeter, LaCoste D-type gravimeter , Scale factor calibration, Jang Bogo Station

We conducted gravity observations using FG5-210 absolute gravimeter (AG) and LCR D-58 relative gravimeter, at Korean Jang Bogo Station (JBS), in 2019-2020 Austral summer season.

The AG measurements were successfully done at two points named JBSAG1 and JBSAG2, and obtained about 19000 and 14400 drops of data, respectively, with the measurement precisions better than 0.4 µGal (1 µGal=10-8 ms-2). In addition, the relative gravity measurements were conducted at 10 newly established gravity points in JBS to supplement the absolute gravity points.

In JBS, superconducting gravimeter (SG) observation with iGrav-021 has been continued since 2016. Since SG is a relative gravimeter, the calibration of the scale factor is essential for long-term gravity monitoring. Moreover, D-58 is also required the scale factor calibration as well. To calibrate the scale factors of these gravimeters, we first estimated the iGrav-021scale factor by the parallel observations with the FG5-210. And then the D-58 scale factor were indirectly estimated by the parallel observations with iGrav-021. This procedure worked well, and these calibrations should ensure the accurate gravity monitoring in the future.
Since we have already reported the details about the AG measurements at the 2020 JpGU meeting, we will mainly report the results of relative gravity measurements and the scale factor calibrations in this paper.