Geophysics Instrumentation

What instruments are used in geophysics? The instruments used in geophysics are seismographs, land and water magnetometers, and geoelectrical instruments.

The different types of seismographs are the channel seismic recorders, seismographs for refraction, depth to bedrock teaching and groundwater studies, high-bandwidth digital marine seismic streamers, seismic recorders for analog streamers and software that processes reflection, refraction, surface wave and marine data.

What are geophysics instruments used for? They are used geological studies. The studies concern rock and soil studies and surveying the earth. The subdivisions of geological study are geophysics, geochemistry, mineralogy, hydrology, and geomorphology.

Geophysical instruments like seismographs and magnetometers help in the study of earthquakes and surveying the earth’s crust. The function of a seismograph is to detect and record the intensity, direction, and duration of an earthquake. From this information scientist can calculate how much energy was released and to pinpoint the source of the earthquake.

A magnetometer measures the strength and direction of magnetic fields. The two fundamental kinds of magnetometers are the scaler magnetometer and the vector magnetometer. The first type measures the total strength of the magnetic field. The second type measures the components of a magnetic field in a certain direction.

Magnetometers can measure the magnetic pull of metals. Therefore, they can locate iron in ships and other objects. They can be used to find wrecked ships, archeological sites and buried treasures.

About 12 years after WWII gains in the geophysical apparatus used for the purpose of prospecting oil. The specific success was in developing an instrument that could accurately register anomalies in the earth’s crust from an airplane.

Improvements in geophysics instrumentation keep moving ahead and from 1970-1974 advances were made in marine geophysical instrumentation systems. And innovations in different areas of geophysics instrumentation continued so that these days digital models and computer data are used.

Geophysics instruments are used in the study of archeological geophysics.  They have taken the geophysical used in mineral exploration, engineering and geology. The main instruments used are magnetometers, electrical resistance meters, ground-penetrating radar and electromagnetic conductivity meters.

Electrical resistance meters are useful when archeological features have a higher or lower resistivity than surrounding ground or rock formations. Electromagnetic conductivity meters work in a similar manner as electrical resistance meters, but have some advantages. They don’t need direct contact with the ground and they will work in conditions that electrical resistance meters won’t work in.

Most of the time in archaeological endeavors the gradiometer configuration of the magnetometer is preferred to the use of one sensor because it gives better picture of small objects on the surface of the ground.

For the use of the ground penetrating radar sand soils are perfect. In this use a radar signal is aimed at the ground subsurface objects and layering reflections are detected

by the receiver. The amount of time it takes the signal to travel is an indication of depth of the object detected.

Although this article doesn’t cover all of the ways in which geophysics instrumentation is used by geophysicists, it should supply an idea of the wide range of uses of the instruments.