Re: GRDGRADIENT problem

On 21-02-2014 03:03, Mr Abhash Kumar wrote:
> Hi,
> I used grdcut to cut my slab grid file at the center 
> longitude/latitude of -71.5/-15.5 and calculated downdip direction for 
> this small grid file.
>
> *grdcut slabsurf2.grd -Gslabcut.grd -R-71.6/-71.4/-15.6/-15.4 -V*
> *grdgradient slabcut.grd=nf/-1 -D -Gslabcutslope.grd -M*
>
> I got the following results:
>
> -71.5813953488  -15.3986928105  278.410919189
> -71.5069767442  -15.3986928105  281.828369141
>
> I can clearly notice in my slab map that the downdip direction should 
> be in the range of 20-80 degree for this region. It doesn't make sense 
> to have slab dipping in the SW, when it appears to be dipping along 
> NE. I would really appreciate any advice.

If you don't believe me, make a 3d plot with grdview. It is always 
instructive to see the effect off a Z +down has in our perception of relief.



>
> Thanks
> Abhash kumar
> University of North Carolina at Chapel Hill
>
>
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