Table 1. Global Martian VN volume estimates based on PBTH method and volume of water required.
|
Topographically derived VN16 |
Combined VN (topographically derived14
and manually digitized30) |
|||
|---|---|---|---|---|
| Volume or mass | GEL (m)* | Volume or mass | GEL (m)* | |
| VVN (MOLA) | (1.74±0.8) × 1014 m3 | 1.20 | (2.23±1.0) × 1014 m3 | 1.54 |
| VVN (HRSC†) | (2.31±1.1) × 1014 m3 | 1.59 | (2.96±1.4) × 1014 m3 | 2.04 |
| Vs=VVN/(1−λ) | (3.55±1.6) × 1014 m3 | 2.45 | (4.55±2.1) × 1014 m3 | 3.14 |
| Ms=Vs × ρs | (1.03±0.5) × 1018 kg | — | (1.32±0.6) × 1018 kg | — |
| Vw=Ms/Ls | (6.86±3.2) × 1017 m3 | 4.74 × 103 | (8.80±4.1) × 1017 m3 | 6.08 × 103 |
GEL, global equivalent layer; HRSC, High/Super Resolution Stereo Colour Imager; Ls, sediment load in water=1.5 kg m−3; MOLA, Mars Orbiter Laser Altimeter; Ms, mass of sediment; PBTH, progressive black top hat; VN, valley network; Vs, volume of sediment; VVN, volume of VN; Vw, volume of water; λ, porosity=0.35; ρs, density of sediment=2,900 kg m−3.
*Errors for GEL are all less than 10−6 m.
†Scaled based on regression line shown in Fig. 3c.