Açıklama
The United States Geological Survey (USGS) 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. The agency lives by its motto: "Science for a changing world."The USGS publishes technical reports, data series, investigation results, and procedural documents for internal USGS use and the general public.