Fig. 5

Array positioning results at KAMN. a Time-series of the array positions. Open black circles, blue x-marks, red crosses, open green squares show the solutions estimated by Method-1, Method-2, Method-3, and Method-4, respectively. Cyan and orange vertical lines indicate the campaigns that the equivalent gradient depths are estimated to be lower than zero and larger than the seafloor depth, respectively. b Scatter diagram of the shallow gradients estimated by Method-3 and the deep gradients estimated by Method-2. Red and blue symbols represent EW and NS components, respectively. The solid line represents the linear regression line. The regression equation and the correlation coefficient are shown. c Scatter diagram of the equivalent gradient depths and the gradient depths estimated by Method-3. The colors of plots indicate the intensity of the shallow gradients estimated by Method-3. Solid and dashed vertical lines show the depths of zero and the seafloor