A Network of Superconducting Gravimeters Detects Submicrogal Coseismic Gravity Changes
Yuichi Imanishi,1*
Tadahiro Sato,2
Toshihiro Higashi,3
Wenke Sun,4
Shuhei Okubo4
With high-resolution continuous gravity recordings from a regional
network of superconducting gravimeters, we have detected permanent
changes in gravity acceleration associated with a recent large
earthquake. Detected changes in gravity acceleration are smaller
than 10
–8 meters seconds
–2 (1 micro-Galileo, about
10
–9 times the surface gravity acceleration) and agree
with theoretical values calculated from a dislocation model.
Superconducting gravimetry can contribute to the studies of
secular gravity changes associated with tectonic processes.
2 National Astronomical Observatory of Japan, 2-12, Hoshigaoka, Mizusawa, Iwate 023-0861, Japan.
3 Department of Geophysics, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
4 Earthquake Research Institute, University of Tokyo, 1-1-1, Yayoi, Bunkyo, Tokyo 113-0032, Japan.
* To whom correspondence should be addressed. E-mail: imanishi{at}ori.u-tokyo.ac.jp
