Diego635
commented
4 years ago When treating large areas, this isn't effective. By removing the values and interpolating afterwards from the surroundings, we have areas that are surrounded by 0 (shoreline) and where the closest negative/positive pixel is too far away to be taken into consideration by the interpolation algorithm. So that area gets the value 0. This creates large patches (artefacts) with altitude 0.
This is solved by taking the original topography at those areas, when available, and rescaling it between -5 and -0,1 / between 0,1 and 5. If we can't find original topography / bathymetry values for them, they should be NaN.
jaminzoda
The paleoshorelines tool looks inside the shorelines mask and if the values are below sea level it brings them up above it, and if outside the shorelines mask values are above sea level, they are set below it. The values are set below and above sea level with a rescaling technique, which preservers the initial pattern of the relief, rescaling the elevation values between new minimum and maximum values. This approach has a con: when setting the values above zero we define new maximum (e.g 5 m); in some cases there might be a need to set it higher (e.g. 100 m); In this case we may end up with an artifact with high values close to the shoreline and low elevation behind it. To solve this issue, we can instead of rescaling set the values to NAN and then interpolate them.