Magnetic Conversion Factors

To convert from SI units to cgs units for use in GM-SYS, use the conversion table below. For example, divide magnetization reported in A/m by 10³ for input into GM-SYS.

Conversion Factors

Quantity	cgs unit	SI Unit	Conversion
Magnetic field (B)	gauss (G)	tesla (T)	1 gauss=0.0001 T
"	gamma [1]	nanotesla (nT) [2]	1 gamma [1] = 1 nT [2]
Field intensity (H)	oersted (Oe)	A/m	1 oersted = 10³ / 4 A/m
Magnetization (M)	gauss [3] (G)	A/m	1 gauss [3] = 10³ A/m
Susceptibility ( or S)	dimensionless	dimensionless	1 (cgs) = 4 (SI)
Koenigsberger ratio (Q)	dimensionless	dimensionless	1 (cgs) = 1 (SI)
[1] 1 gamma = 10-5 gauss [2] 1 nanotesla = 10-9 tesla [3] Also called emu/cm³.		modified from Blakely (1995)

Notes:

• Although susceptibility is dimensionless, it differs by a factor of 4 between the two systems.
• The defining equations above require Earth magnetic field values to be given in oersted (cgs) or A/m (SI). However in the geophysical literature, Earth magnetic field values are commonly given in gammas (cgs) or nanotesla (SI) which is what GM-SYS expects.