Sunday, February 09, 2003

Well, let's see. sscdc.net is completely down -- email and sites. Wonderful. I wonder if the city pulled the plug and didn't bother to tell me, even though they had sent me all the information to put up this weekend -- which took me about five hours, since it had so many problems. Russ isn't here, but he should be home soon. And the damned phone keeps ringing.

I can tell right now that it's not going to be a good day. Just not good in general. I'm sure I'll manage to get things worked out soon and not feel so annoyed, but at the moment, it's not my best mood.

I did, however, have more thoughts on glaciers last night.

Ice takes more space than the water it becomes in melting. I seem to remember that's because of air molecules caught between the frozen parts -- the same thing that makes those pretty patterns in snowflakes? Anyway, let's say that you want to have a single glacier provide the water for a river. How long of a river? The glacier would have to be far away if you want a desert between, or else the climate wouldn't be right. So, are we talking thousands of miles? The Missouri (which is just a few blocks away from where I live) is about 2700 miles long, and it flows into the Mississippi, which is even longer -- another reminder that it's a long distance from the source of a river to the end.

And how long has the river been flowing? To have any sort of civilization grow up around the banks, it would have to be pretty steady and old. Oh -- and one thing I did realize, talking about gorges and such -- it could do something like that through a desert. There is a lovely one in New Mexico -- Rio Grande Gorge? I've stood and looked down at. Beautiful place.



Okay, for the glacier (or even a group of glaciers) to provide the water to keep that river flowing for centuries, it would have to have a huge ice pack. I'm not even sure how large it would have to be to continually sustain something like that. Could the front edge of something that large be so far from the back that the ice continues to accrete at the far end, snow continuing to fall and compress, pressing the front forward? Isn't that how mountain glaciers work now? How much would it take to form a gigantic, renewable, glacier?

I seem to remember reading that glaciers are very heavy, too. And as they retreat, the ground lifts, and could cut off the front edge of a glacier from the area from the path the ice melt had taken in the past, which would mean the end of the river as it looked for a new path. It might still end up in the same general drainage system though, if it were all 'facing' properly.

All in all, it's an interesting look at the problems of a glacier and how you could use it.

No comments: