Ground conductivity refers to the electrical conductivity of the subsurface of the earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

.

Radio propagation

Ground conductivity is an extremely important factor in determining the field strength and propagation of surface wave

Surface wave

In physics, a surface wave is a mechanical wave that propagates along the interface between differing media, usually two fluids with different densities. A surface wave can also be an electromagnetic wave guided by a refractive index gradient...

 (ground wave) radio transmissions. Low frequency

Low frequency

Low frequency or low freq or LF refers to radio frequencies in the range of 30 kHz–300 kHz. In Europe, and parts of Northern Africa and of Asia, part of the LF spectrum is used for AM broadcasting as the longwave band. In the western hemisphere, its main use is for aircraft beacon,...

 (30-300 kHz) and medium frequency

Medium frequency

Medium frequency refers to radio frequencies in the range of 300 kHz to 3 MHz. Part of this band is the medium wave AM broadcast band. The MF band is also known as the hectometer band or hectometer wave as the wavelengths range from ten down to one hectometers...

 (300-3000 kHz) radio transmissions are particularly reliant on good ground conductivity as their primary propagation is by surface wave.

Other uses

Ground conductivity is sometimes used in determining the efficiency of a septic tank

Septic tank

A septic tank is a key component of the septic system, a small-scale sewage treatment system common in areas with no connection to main sewage pipes provided by local governments or private corporations...

, using electromagnetic induction

Electromagnetic induction

Electromagnetic induction is the production of an electric current across a conductor moving through a magnetic field. It underlies the operation of generators, transformers, induction motors, electric motors, synchronous motors, and solenoids....

, so that contaminants do not reach the surface or nearby water supplies.

External links

• Ground conductivity maps in the United States (provided by the Federal Communications Commission
  Federal Communications Commission
  The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...
  
  and includes large scale map)