Changes

==Theory==

==Theory==

Gravity effects caused by subsurface geology are superimposed upon the earth's overall gravity field. These effects, called anomalies, are typically less than 100 ppm of the total field. Several corrections are made to remove the earth's field from the total measurement to image these anomalies. For petroleum exploration, gravity is measured in milligals (mGal). Typical exploration anomalies are generally

Gravity effects caused by subsurface geology are superimposed upon the earth's overall gravity field. These effects, called anomalies, are typically less than 100 ppm of the total field. Several corrections are made to remove the earth's field from the total measurement to image these anomalies. For petroleum exploration, gravity is measured in milligals (mGal). Typical exploration anomalies are generally < 25 mGal. Typical gravity sensors are capable of measurements < 0.5 mGal.

==Gravity vs. magnetics==

==Gravity vs. magnetics==