Table 2 Site conditions and tephra thicknesses at the Mt. Hagen, PNG experimental plots
Plot No | Vegetation | Slope angle (degrees) | Initial thickness (mm) | Subsequent thickness (mm) | ||||
|---|---|---|---|---|---|---|---|---|
7 days | 16 days | 30 days | 236 days | 767 days | ||||
1 | Grasses 20–40 mm; <5% bare ground; dense root mat | 5 | 50 | 35 | 25 | ~20 | 25 | 20–30 |
2 | Grasses 20–40 mm; 40–50% bare ground | 0.5 | 50 | 35 | 25–30 | 20–25 | 20–30 | 25–30 |
3 | Grasses <20 mm; 40–50% bare ground | 2 | 30 | 29 | ~15 | 10 | 10–12 | 15–20 |
4 | Dense tall grasses 200–350 mm; no bare ground | 1 | 20–30 | - | - | - | 20 | <20 |
5 | Dense tall grasses 200–3000 mm; no bare ground | 1 | 50–60 | - | - | - | 40 | 25–30 |
6 | Grasses 20–40 mm; <5% bare ground | 7 | 10 | - | - | - | 5–10 | <5 |
7 | Bare soil dug over to spade depth | 3.5 | 25 | - | >10 | - | ~10 | ~20 |