27 April 2005
I meant to update this blog sooner than this but I have been studying for a Historical Geology Final- It’s been a real bear.
Some odds and ends on my mind tonight:
The Mets. over at Huntsville NWS went out and did a storm survey of Dekalb county after Friday’s storm and upgraded the severe thunderstorm to an F zero tornado.Look for a pic of the wall cloud over Fort Payne on our web site picture gallery.
I’m planning a series of BLOGS on global warming.
There is so much confusing info out there, I think it would be a good idea to write up what is known with a high degree of certainty first. I expect to take some heat though. It seems a lot of people get there science on global warming (either view point) from talk radio hosts these days…
On the subject of planetary climate, Lets mention an almost forgotten scientist. Milutin Milankovitch.
Back inthe 1920’s he proposed a theory for explaining the glacial cycles that show up so clearly in the rock record.
Milankovitch cycles are based on 3 variations in earth’s orbit.
1.ECCENTRICITY- which varies on a 100,000 year cycle
2. OBLIQUITY. Which causes the seasons
(presently at 23.5 degrees) This is a 41,000 year cycle
3. PRECESSION: The changing of the dates of the seasons.
Right now Dec. 21st is the beginning of Winter, when we are closest to the sun. In 11,000 years it will be June 21st. When we are farthest from the sun.
This theory is still controversial among researchers, but most think it has a lot to do (in one way or another!) with the coming and going of the ice sheets over the continents.
The Naval Observatory has a good explanation of these cycles on it’s web site. I have linked directly to it at the top of this blog.Click on LINK.
Over the last 250,000 years..the earth has been a snowball most of the time and we may very well be headed back that way again…well after the ice caps melt from global warming and Birmingham is ocean front property..but I will save that for another blog…