Additional file 1 of Determination of the source parameters of the 2011 Tohoku-Oki earthquake from three-component pre-P gravity signals recorded by dense arrays in Japan

Additional file 1: Fig. S1. Average noise spectrum of the Hi-net tiltmeter records. Fig. S2. Magnitude maps of the three-component pre-P gravity signal. Fig. S3. Stacked waveforms of the horizontal NS component data and synthetics.