Encyclopedia of Earth
Encyclopedia of Earth: Ecoregions: Aleutian Islands Tundra
Discusses features of the unique ecoregion, the Aleutian Islands tundra. Covers wildlife, threats to preservation, and conservation initiatives.(Updated August 26, 2012)
Wikimedia
Wikipedia: Pacific Ring of Fire
Wikipedia offers information on the location of the Pacific Ring of Fire, an area of frequent earthquakes and volcanic eruptions. Map included.