Earthquake
Largest known earthquake database with statistics and information about locations, magnitudes, with google earth support, search engine and RSS feeds
http://earthquakedb.com/
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Tsunami
Largest known tsunami database with statistics and information about locations, magnitudes, with google earth support, search engine and RSS feeds
http://tsunami.name/
Volcanoes Information
Browse all the currently known volcanoes with map locations, times of eruptions and much more!
http://volcanodb.com/