GLIMS Minimum Requirements list

[Jeffrey S Kargel]

Bruce,

>Once the ID is set, it won't change, even when the glacier does.  If, in
>the future, a glacier recedes past its ID position, there shouldn't be a
>problem with retaining the ID that is now over dirt, since it's unlikely
>that a different glacier will advance to this position.  Anyone know of
>pathological cases where this might happen?

Not me, but I'd bet a large quantity of beer (good, expensive beer; a
round for everybody-- but then you have be playing piano for me to pay
up) that it does happen in areas where surge-type glaciers
are common.  Glacier A surges, then wastes back rapidly, and then wanna-be
tributary glacier B surges into the 'dirt' left by glacier A. It is
probably
not very common to happen on the time scale that GLIMS will be dealing
with (100-1000 years maybe? hopefully), and especially infrequent or not
during the at all next 5 years (life of ASTER), but it might happen.  A
few cases can be dealt with by clear, strategic use of a comment field.

Including but going beyond this issue: Is there a technical way (and
rationale)
for having any field to allow an asterisk or other footnote symbols to link
a
particular data entry to a text comment?  Well, maybe that's making it too
complex, and maybe we can assume that users can and will read comments.
But you can consider it. A possible reason to include footnoting: mindless
analysis of a big database could "weed out" or flag particular data entries
that are tied to specific comments.

>> Are there any
>> science/application reasons or technical reasons that would
>> prevent this definition (lat/lon of approximate
>> glacier center) of glacier ID?
>
>If there are, they should be identified soon!

I can't think of any.  Besides use of an ID strictly as an ID, people MIGHT
use the ID as a quick-and-dirty way of plotting glacier locations or of
counting
the numbers of glaciers, but for any exacting science/application
requirement
involving spatial analysis or spatial presentation of glacier locations,
there will be the glacier polygons that can be used instead. I'd vote for
going forward with and building on your plan as you describe it.

--Jeff K