Gravity anomaly of a dipping prism

AI Thread Summary
The discussion centers on writing a MATLAB script to calculate the gravity anomaly of a dipping prism using Hjelt's equations from a 1974 Geoexploration paper. The key equation is Δg=G.Δρ.T0, with specific notes on the sign of φ based on the indices of u, v, and w. There is confusion regarding the application of these equations, particularly the notation used by the author, which is described as unclear and cumbersome. A suggestion is made to derive the gravity effect formula for simpler cases, such as a rectangular prism or semi-infinite slab, to gain clarity. Additionally, Telford et al.'s 1990 work on Applied Geophysics is recommended for clearer notation and understanding, although it primarily addresses 2D anomalies.
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I am trying to write a MATLAB script which calculates the gravity anomaly of a dipping prism, using the equations of Hjelt, published in Geoexploration in 1974, issue 1 volume 12.
Δg=G.Δρ.T0
where
http://img580.imageshack.us/img580/6528/41828644.png
and
http://img31.imageshack.us/img31/4226/phiih.png
at the end of the page there are two notes, the second one says:
"Note 2: The sign of each \phi is positive, whenever there is an even number of 2s in the indices
of u, v and w. (u1, - v1 - w1, u1 - v2 - w2, etc.)"

I just can't get my head around what exactly this means and how to apply it.I have expanded the equations for each \phi, using the limits for u, v and w, but they are very long, so will post them only if needed.
 
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I had a quick read of the paper. Granted, the notation that the author uses is not clear and rather cumbersome.

I am not sure whether this helps, but if I were you, I would derive the gravity effect formula for a simple case (i.e. rectangular prism, semi-infinite slab, etc) and see how the results work out.

I do not have it at hand right now, but Telford et al., 1990 (Applied Geophysics) has a decent section on gravity methods. I would also take a look at Telford as I recall the notation is clearer.

cheers.
 
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I think Telford gives the equations only for 2D anomalies
 

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