"Tutte le cose sono collegate tra loro. Qualsiasi cosa accade alla terra, accade ai figli della terra".
Geological Survey (USA)
The United States Geological Survey (USGS, formerly simply Geological Survey) is a scientific agency of the United States Government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it.
www.usgs.gov