Fig. 1: Location and tectonic setting of Arima hot springs.
From: Hot springs reflect the flooding of slab-derived water as a trigger of earthquakes
a Index map showing western Japan and Nankai Trough with contours to top of the Philippine Sea slab25 (black dashed lines). b Map showing locations of the epicenter of 1995 Kobe earthquake (yellow star), monitoring sites of precursory changes in Cl33 (yellow circle) and Rn34 (yellow square), and active faults53 (purple lines). c Map showing sampling sites of hot springs (red circles; AR1-AR7) and cold springs/rivers (blue crosses) with divides for nearby rivers (white dashed lines), active53/nonactive54 faults (thick/thin purple lines), and negative Bouguer anomaly domain30 (pink ellipse). (a) and (b) were created using the ArcGIS Pro 3.1.2 (Esri Inc.) with digital elevation model of the ETOPO 2022 15 Arc-Second Global Relief Model55 (in a) and the Japan Flow Direction Map56 (in b). (c) was created by editing GSI Tiles (elevation) at Geospatial Information Authority of Japan website (https://maps.gsi.go.jp/vector/#13.048/34.7846/135.219595/&ls=vstd%7Crelief%7Crelief_free&disp=101&d=l&reliefdata=35G0000FFGAG0095FFGFAG00EEFFG12CG91FF00G1F4GFFFF00G3E8GFF8C00GGFF4400).
