223,850 sq km (2003)
Total renewable water resources:
3,069 cu km (1985)
Freshwater withdrawal (domestic/industrial/agricultural):
total: 477 cu km/yr (13%/46%/41%)
per capita: 1,600 cu m/yr (2000)
Natural hazards:
tsunamis; volcanoes; earthquake activity around Pacific Basin; hurricanes along the Atlantic and Gulf of Mexico coasts; tornadoes in the Midwest and Southeast; mud slides in California; forest fires in the west; flooding; permafrost in northern Alaska, a major impediment to development
volcanism: the United States experiences volcanic activity in the Hawaiian Islands, Western Alaska, the Pacific Northwest, and in the Northern Mariana Islands; both Mauna Loa (elev. 4,170 m, 13,678 ft) in Hawaii and Mount Rainier (elev. 4,392 m, 14,409 ft) in Washington have been deemed "Decade Volcanoes" by the International Association of Volcanology and Chemistry of the Earth's Interior, worthy of study due to their explosive history and close proximity to human populations; Pavlof (elev. 2,519 m, 8,264 ft) is the most active volcano in Alaska's Aleutian Arc and poses a significant threat to air travel since the area constitutes a major flight path between North America and East Asia; St. Helens (elev. 2,549 m, 8,363 ft), famous for the devastating 1980 eruption, remains active today; numerous other historically active volcanoes exist, mostly concentrated in the Aleutian arc and Hawaii; they include: in Alaska: Aniakchak, Augustine, Chiginagak, Fourpeaked, Iliamna, Katmai, Kupreanof, Martin, Novarupta, Redoubt, Spurr, Wrangell; in Hawaii: Trident, Ugashik-Peulik, Ukinrek Maars, Veniaminof; in the Northern Mariana Islands: Anatahan; and in the Pacific Northwest: Mount Baker, Mount Hood
Environment - current issues: