A geophysicist studies Earth’s structure and properties. Geophysicists use a variety of methods, but often use gravity, magnetic, and seismic methods. Geophysicists apply their work to many different types of study. Some are finding energy resources such as oil and rocks that contain valuable elements such as nickel, copper, and rare earth elements. Some geophysicists are assessing earth properties for environmental hazards while others may look at subsurface conditions for construction. Research geophysicists study the internal structure of the Earth, how the Earth has changed over time, motion of the plates on the Earth’s surface, earthquakes, and other features of the Earth.