Fig. 2
From: Thoron, radon and microbial community as supportive indicators of seismic activity in groundwater
(a) Visualization of the component planes of the hydrogeochemical data for the Pohang area from the SOM results. The pink color indicates high values of the nodes, while the sky blue color represents low values. (b) U-matrix visualization and pattern of group formation from the SOM results in the Pohang area. The label on each hexagon denotes the sample number.
