A Procedure to Correct Errors in Depth Estimation from Slope Hale Slope Method

Abstract

The novel method named slope half slope for depth estimation of the causative magnetic field proposed by Peters (1949) has been investigated to determine the possible percent errors in depth estimation to magnetic sources situated at different latitudes. A sequence of models represented by thick dykes with various depths and with different values of field inclination (0 to 90°) has been used to estimate the percentage errors for the different inclination values. A procedure to correct the errors in depth estimate has been discussed. The calculated percent errors range between positive and negative values for the same angle of inclination at various depths. This raises difficulties to use a formula concerning the factor to adjust the estimated depths and to overcome this problem. Therefore, a new approach has been adopted to correct the estimated depth values. A relationship between the horizontal distance at the tangential point and center of the maximum slope with the actual and estimated depths is found. Two straight lines are plotted from this relation and they are intersected at a certain point for each inclination value. The location of this point defines whether the difference between the actual and the estimated depth values will be added to or subtracted from the estimated depth to get the actual depth. In real depth determination, the correct value is determined by defining the intersect point between the estimated depth and the horizontal distance and then calculating the difference from the actual slope line for the assigned inclination angle. Each inclination angle has its own relation and intersected point that can be used to determine the actual depth.

Keywords

• Magnetic depth estimation, slope method, correction procedure, percent errors in depth estimation, percent errors with inclinations.