Geophysicists

Geophysicists use the principles and techniques of geology, physics, chemistry, mathematics, and engineering to perform tests and conduct research on the surface, atmosphere, waters, and solid bodies of the earth. They study seismic, gravitational, electrical, thermal, and magnetic phenomena to determine the structure and composition of the earth, as well as the forces causing movement and warping of the surface.

Many geophysicists are involved in fieldwork, where they engage in exploration and prospecting. Others work in laboratories, where research activities are the main focus. They use computer modeling software to develop and test their hypotheses. Photogrammetry, Geographic Information Systems, and remote sensing technologies are often used to gather geophysical data. In general, their instruments are highly complex and designed to take very precise measurements. Most geophysicists specialize in one of the following areas.

Geodesists measure the shape and size of the earth to determine fixed points, positions, and elevations on or near the earth's surface. Using the gravimeter, they perform surveys to measure minute variations in the earth's gravitational field. They also collect data that is useful in learning more about the weight, size, and mass of the earth. Geodesists are active in tracking satellites orbiting in outer space.

Geomagnetists use the magnetometer to measure variations in the earth's magnetic field from magnetic observatories and stations. They are also concerned with conditions affecting radio signals, solar phenomena, and many other aspects of space exploration. The data gathered can be most helpful in working with problems in radio and television transmission, telegraphy, navigation, mapping, and space exploration and space science.

Applied geophysicists use data gathered from the air and ground, as well as computers, to analyze the earth's crust. They look for oil and mineral deposits and try to find sites for the safe disposal of hazardous wastes.

Exploration geophysicists, sometimes called geophysical prospectors, use seismic techniques to look for possible oil and gas deposits. They may use sonar equipment to send sound waves deep into the earth. The resulting echo helps them estimate if an oil deposit lies hidden in the area.

Hydrologists are concerned with the surface and underground waters in the land areas of the earth. They map and chart the flow and the disposition of sediments, measure changes in water volume, and collect data on the form and intensity of precipitation, as well as on the disposition of water through evaporation and ground absorption. The information that the hydrologist collects is applied to problems in flood control, crop production, soil and water conservation, irrigation, and inland water projects. Some hydrologists study glaciers and their sedimentation.

Marine geophysicists are geophysicists who apply their training to the study of our world’s oceans. They conduct research on how matter and energy affect the ocean. In particular, they study the makeup of the earth’s surface and waters and how geophysical phenomena such as earthquakes, tsunamis, and underwater volcanoes and hydrothermal systems change them.

Seismologists use sound waves to study the earth’s interior structure. They specialize in the study of earthquakes. With the aid of the seismograph and other instruments that record the location of earthquakes and the vibrations they cause, seismologists examine active fault lines and areas where earthquakes have occurred. They are often members of field teams whose purpose is to examine and evaluate possible building or construction sites. They also may explore for oil and minerals. In recent years, seismologists have contributed to the selection of missile launching sites. Seismologists who study the ocean floor can pinpoint areas where earthquakes may occur. Earthquakes can sometimes cause tsunamis, which can kill or injure people in regions far from the earthquake site. Seismologists also try to answer questions such as: What does the deep interior of the earth look like? What is the role of upper earth mantle structures in tectonic plate interactions?

Tectonophysicists study the structure of mountains and ocean basins, the properties of the earth's crust, and the physical forces and processes that cause movements and changes in the structure of the earth. A great deal of their work is research, and their findings are helpful in locating oil and mineral deposits.

Volcanologists study volcanoes, their location, and their activity. They are concerned with their origins and the phenomena of their processes.

Planetologists use data from artificial satellites, telescopes, and sensors on spaceships to study the makeup and atmosphere of the planets, the moon, and other bodies in our solar system. Recent advances in this field have greatly increased our knowledge of Jupiter, Saturn, Pluto, and their satellites.