Changes

[[file:using-magnetics-in-petroleum-exploration_fig14-2.png|thumb|300px|{{figure number|1}}Magnetic profiles of total intensity, regional trend, and residual. After Nettleton.<ref name=ch14r7>Nettleton, 1962, Elementary Gravity and Magnetics for Geologists and Seismologists: Society of Exploration Geophysicists Monograph Series 1, 121 p.</ref> Copyright: Society of Exploration Geophysicists.]]

[[file:using-magnetics-in-petroleum-exploration_fig14-2.png|thumb|300px|{{figure number|1}}Magnetic profiles of total intensity, regional trend, and residual. After Nettleton.<ref name=ch14r7>Nettleton, 1962, Elementary Gravity and Magnetics for Geologists and Seismologists: Society of Exploration Geophysicists Monograph Series 1, 121 p.</ref> Copyright: Society of Exploration Geophysicists.]]

Residual is what remains after regional magnetic trends are removed from the total intensity Residual maps show local magnetic variations, which may have exploration significance. The regional trend of the total intensity can be calculated using a number of techniques, including running averages, polynomials, low-pass filters, or upward continuation techniques. [[:file:using-magnetics-in-petroleum-exploration_fig14-2.png|Figure 1]] shows magnetic profiles of total intensity, regional trend, and residual.

Residual is what remains after regional magnetic trends are removed from the total intensity Residual maps show local magnetic variations, which may have exploration significance. The regional trend of the total intensity can be calculated using a number of techniques, including running averages, polynomials, low-pass filters, or [http://wiki.seg.org/wiki/Dictionary:Upward_continuation upward continuation] techniques. [[:file:using-magnetics-in-petroleum-exploration_fig14-2.png|Figure 1]] shows magnetic profiles of total intensity, regional trend, and residual.

==Total intensity and residual map example==

==Total intensity and residual map example==