[aspect-devel] Dynamic topography

[Wolfgang Bangerth]

Hi Lev,

> I was trying to plot the topography using the output of the Dynamic topography 
> plugin, but in a lot of models it is within 10 meters of zero, even though the 
> min and max topography statistic shows hundreds or even thousands of meters. I 
> was wondering what could be the source of this discrepancy?

These are different things (assuming I interpret your question correctly). The 
topography is something you specify at the initial time as part of the 
geometry. The "dynamic topography" is something that results from the motion 
of the fluid underneath at a given time step. It is how the surface would 
deform in response to the fluid motion if it wasn't rigid.

Or are you saying that the topography you output is due to the moving 
boundary? In that case, if the boundary would move in perfect response to the 
fluid stress underneath, then the "dynamic topography" computed in each time 
step would actually be zero, because there are no excess stresses that aren't 
already accommodated by the displaced surface!

Best
  W.

-- 
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Wolfgang Bangerth          email:                 bangerth at colostate.edu
                            www: http://www.math.colostate.edu/~bangerth/