[Imports] Antarctica coastline/shelf-ice import

Christoph Hormann chris_hormann at gmx.de
Fri Mar 8 23:08:17 UTC 2013

On Friday 08 March 2013, Glen Barnes wrote:
> I'm trying to get a better handle on how this works in practice vs.
> other maps of Antarctica. If we look at a satellite view and map view
> from Google maps the coastline seems to be the grounding line
> although I may be mistaken:

That is right, in map view google displays roughly the grounding line 
and does not depict the ice shelves at all.

> Are you saying we make this whole 'bay' disappear by tagging the
> coasting line as the edge of the ice as opposed to where grounding
> line?

No.  The idea is to display the land, the ice shelves and the ocean in 
distinct ways.  This will require some changes in the rendering style 
of course.

Only if for some reason you only want to display two different 
surfaces - land and ocean - the planned tagging scheme will favour the 
variant with the ice shelves as land.  The reasoning behind this is 
described on http://wiki.openstreetmap.org/wiki/Antarctica/Tagging and 
you can also see this style of display frequently in more abstract 
maps -like:


> I propose tagging the coastline as the grounding line and the 
> ice shelf as an ice shelf. In that way you are describing what the
> real world is rather than a perceived value. The grounding line seems
> to me to represent high tide of the actual unfrozen water.

The grounding line is unaffected by tide since it is far below the sea 
level.  I am not sure what you refer to with 'real world' 
vs. 'perceived value'.  Both the grounding line and the calving line 
are real and both are going to be mapped.


Christoph Hormann

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