Geophysicists study the earth using a variety of methods, including gravitational, magnetic, electrical, and seismic. They study the structure, composition and the physical aspects of the earth and its atmosphere and apply scientific principles in order to solve problems. These scientists use geophysical methods to study the Earth and its composition, including its atmosphere, internal make-up, oceans, electrical and other fields. Geophysicists, involved in field investigation; measure, examine, and explore the physical properties of earth, from below the ground to the atmosphere or from the depths of the ocean to the top of the volcanoes. Geophysicists are involved in environmental studies, archaeological excavations, water resource management, forensic investigations, the Earth's climate, and the causes and prediction of natural phenomena such as earthquakes, volcanic activity, landslides and tsunamis. Geophysicists examine the physical aspects of earth with the help of radar, dynamite, computers, magnetometers and gravimeters. The duties of Geophysicist includes to use software to create and interpret two and three dimensional geophysical data to identify and evaluate sites, generate prospective locations, recommend coordinates, and document assumptions and calculations. They also review and write contracts and specifications for geophysical work, including budgets and timelines. They create and verify seismic, amplitude versus offset (AVO), and other types of models to assess feasibility, safety, and returns.