Geophysicists—-Study physical aspects of earth, including its atmosphere and hydrosphere. Investigate and measure seismic, gravitational, electrical, thermal, and magnetic forces affecting earth, utilizing principles of physics, mathematics, and chemistry.
Geodesists—-Study size, shape and gravitational field of earth. Employ surveying and geodetic instruments such as transits, theodolites and other engineering instruments in setting up and improving network of triangulation over the earth's surface to provide fixed points for use in making maps.
Hydrologists—-Study distribution, deposition, and development of waters of land areas, including form and intensity of precipitation, and modes of return to ocean and atmosphere. Map and chart water flow and deposition of sediment. Measure changes in water volume due to evaporation and melting of snow. Study storm occurrences and evaluate data obtained in reference to such problems as flood and drought, forecasting, soil and water conservation, and planning water supply, flood control, irrigation, and crop production.
Last modified: October 16, 2001