Inside Antarctica: Ice Sheet, Bedrock, Volcanoes, and Hidden Life

Interior Anatomy

Ice Sheet

• Thickness: up to 4,500 m (15,000 ft) — average 2,160 m.
• Volume: 26.5M km³ (70% Earth’s fresh water).
• Age: Basal ice >1M years; EPICA Dome C core 800 kyr.
• Flow: Gravity-driven — 1–10 m/yr interior, 100–1000 m/yr ice streams.

Bedrock

• East Antarctica: Precambrian shield (granite, gneiss) — stable craton.
• West Antarctica: Rift system, younger sedimentary basins, volcanoes.
• Subglacial lakes: 400+ (Vostok 14,000 km²) — isolated ecosystems.
• Mountains: Gamburtsev (Alps-sized, buried), Transantarctic (exposed).

Volcanoes

• Mt. Erebus (3,794 m) — world’s southernmost active volcano; persistent lava lake.
• Mt. Sidley, Mt. Waesche — dormant.
• Subglacial volcanism influences ice dynamics.

Life

• Coastal: Emperor/Adélie penguins, Weddell/crabeater seals, whales.
• Interior: Nematodes, tardigrades, rotifers, microbes in cryoconite holes.
• Subglacial: Chemosynthetic bacteria (Lake Whillans sampled 2013).

Protection

Antarctic Treaty System (1961) — science only, no mining, military ban. Protocol on Environmental Protection (1998) — strict waste, non-native species, EIA rules.