Hobbies And Interests
Resistivity
Resistivity imaging, also known as resistivity tomography, measures variations in the ground's electrical resistance. Electrodes placed in the ground send small electric currents to each other, enabling resistance measurement. Increasing electrode separation provides deeper penetration. Compiling results from depth probes at regular intervals creates a composite image of the ground. Resistivity imaging is more effective than GPR when the ground contains high levels of clay, and is particular useful for finding subterranean water and measuring bedrock depth.
Conductivity
Electromagnetic conductivity (EM), also known as terrain conductivity, measures subsurface electrical conduction. Highly efficient at finding buried metals and inorganic plumes, EM detectors work similarly to metal detectors. Carried above ground, the EM detectors enable rapid surveying of large areas. Different types of EM detectors measure varying depths from 20 feet to 100 feet. EM surveys are ideal for finding buried metallic objects, contaminant plumes, bedrock fractures and minerals.
Microgravity
Microgravity surveys detect tiny changes in Earth's gravity. As Earth's composition is not perfectly uniform and has variations in height, gravity differs. Microgravity surveys detect these differences, usually caused by underground cavities or changes in the density of subterranean material. Accurate to changes as small as 1 part in a billion, modern microgravity surveys are particularly useful for urban areas where traffic, infrastructure and noise levels prohibit other geophysical surveying. Microgravity surveys are useful for archeology, detecting coal mines, geological modeling and studying landfills.
Magnetometry
Magnetometry measures and maps patterns of soil magnetism. Magnetometry picks up magnetic variations in the soil caused by past human activity. Activities, such as burning, alter the magnetic properties of iron particles in soil; these variations are detectable by a magnetometer. Magnetometer users remove all metal objects from their person before conducting a survey to avoid contamination. Able to penetrate to 7 feet, magnetometers find buried features where past human activity took place.