Re: Coastline Data - Ronne Ice Shelf

Jeff,

The Ronne ice shelf was included as part of Antarctica proper in the
USGS dataset that I used as a starting point in creating "Earth..1",
"Earth..2", and "Earth..3" and I had no good way to create the
necessary boundary line separating it from the continent.

I recently created an "Earth..4" which, among other things, includes
boundary lines for all the major ice shelves, including the Ronne,
and makes it possible to include them or exclude them at will (though
I have not yet created an example showing how to do that from NCAR
Graphics, because I got side-tracked on other things).

I could not find sources of digital data for the ice shelves, so,
eventually, I worked out a way to display the Blue Marble satellite
image of Antarctica as a background for the display in my database
editor and then essentially free-handed the desired ice-shelf
outlines. In the case of the Ronne and the Ross, it was a bit
difficult to determine just where some portions of the outlines ought
to go - and, in fact, comparing different maps of Antarctica reveals
that different map makers have created different versions of these
portions.

I also used the National Geographic map of Antarctica as a guide,
but, since it is available to me only in paper form, my use of it
amounts to eye-balling my outlines to make sure that they are not
grossly different from NG's.

Mary can tell you when "Earth..4" will be officially released.

Dave Kennison

On Sep 30, 2008, at 1:09 PM, Jeff Jonas wrote:

> Hey Folks,
>
> Some scientists I work with have commented that the coastline around
> Antarctica (South Pole), that I draw with NCAR Graphics, includes the
> Ronne ice shelf as part of that coastline. They were suggesting
> that this
> was probably a mistake, and wanted to know if I had a coastline map
> that did not include the Ronne ice shelf.
>
> Has anyone else been questioned about this ??
>
> Is there a way to omit the Ronne ice shelf from the NCAR Graphics
> coastline map drawing ?? When I examined the control labels for the
> area around Antarctica, I saw no reference to it in the EZmap area
> identifiers. Just references to islands around Antarctica.
>
> Also, what was the source for the NCAR Graphic's coastline map ??
>
> Thanx all !
> Jeff
> --
> Jeffrey Jonas
> NASA/GISS at Columbia University
> jjonas_at_giss.nasa.gov
> (212) 678-5532
> _______________________________________________
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> ncarg-talk_at_ucar.edu
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Received on Thu Oct 02 2008 - 16:50:36 MDT