1. The correction applied to reflection or refraction arrival times to reduce observations to a common reference datum. 2. In gravity, the sum of the free-air and Bouguer corrections. The elevation correction is obtained by multiplying the difference between station and reference elevation by the elevation correction factor (ECF): ECF=(0.09406–0.01278 ρ) mGal/ft=(0.3086–0.04192 ρ) mGal/m, where ρ=density in g/cm3.