Figure 3: Example of PBTH-derived VN depth and spatial distribution.
From: New Martian valley network volume estimate consistent with ancient ocean and warm and wet climate

(a) VN boundary overlain on MOLA DEM shaded relief (see c for location). (b) VN depth. (c) Global distribution of zonal mean VN depth by geologic unit43. (d) Regression relating volumes extracted from MOLA and HRSC data based on 50 random samples (location shown as triangles in c). The regression equation is: y=1.3215x+5 × 109, R2=0.79.