Fig. 1
From: Measurement of geomagnetically induced current (GIC) around Tokyo, Japan
0.1-s data of X-component geomagnetic field at KAK (top-left panel), negative values of its time derivative (middle-left panel), and Y-component geoelectric field at KAK (bottom-left panel) of the 22 June 2015 SSC and their frequency spectra (right panels)