For a magnetic anomaly modeled as an isolated pole, the horizontal separation between the maximum and minimum of the total-field profile is related to the depth of the pole and the local field inclination (here given via the H:Z ratio).
With H:Z = 3:1, tan(I) = Z/H = 1/3, so sin I = 1/sqrt(10), cos I = 3/sqrt(10). For an isolated pole, differentiating the total-field...
Full option-by-option analysis available to enrolled students.