Earth's magnetic field, also known as the
geomagnetic field, is the
magnetic field that extends from the
Earth's interior out into space, where it interacts with the
solar wind, a stream of
charged particles emanating from the
Sun. The magnetic field is generated by
electric currents due to the motion of
convection currents of a mixture of molten iron and nickel in the
Earth's outer core: these convection currents are caused by heat escaping from the core, a natural process called a
geodynamo.
Intensity
The intensity of the field is often measured in
gauss (G), but is generally reported in
nanoteslas (nT), with 1 G = 100,000 nT. A nanotesla is also referred to as a gamma (γ).
The Earth's field ranges between approximately 25,000 and 65,000 nT (0.25–0.65 G) (Conversion ... 25,000 to 65,000 nanoTesla = 25 to 65 microTesla)