z

downward from the iceberg surface. Its mass density is

ρ_{i} (z) = 300 + 12 z

for

0 \leq z \leq 50

m and

900 kg m^{- 3}

below that. The mass per unit horizontal area is

\frac{m}{A} = \int_{0}^{50} (300 + 12 z) d z + \int_{50}^{300} 900 d z = 30000 + 225000 = 255000 kg m^{- 2} .

(1)

By Archimedes' principle, the draft is

d = (m / A) / ρ_{w} ≃ 248.78

m. The iceberg freeboard is therefore

300 - d ≃ 51.22

m. The specified snow-to-ice density is reached at

z_{t} = \frac{800 - 300}{12} ≃ 41.67 m, z_{t} lies about 9.55 m above the waterline .

(2)

The more porous snow and firn are consequently above water: atmospheric warming, meltwater infiltration, compaction and refreezing can modify them. At the waterline and below, dense ice is exposed to oceanic heat transfer and wave erosion, which can undercut the berg and cause breakage. If the porous transition were submerged, water infiltration and ocean heat could act directly on that material, changing the erosion and collapse mechanisms.