Skip to comments.Ice ages: Why North America is key to their coming and going
Posted on 08/11/2013 6:07:09 AM PDT by SunkenCiv
Scientists have long tried to figure out what causes the ebb and flow of ice ages. New data suggests a novel explanation for why the mile-thick blankets of ice retreat so quickly: They become too heavy.
For the last 900,000 years, mile-thick ice sheets have waxed and waned in the Northern Hemisphere with remarkable regularity building over periods of about 100,000 years and retreating in the space of only a few thousand years, only to repeat the cycle.
Now, a team of scientists from Japan, the US, and Switzerland suggests that the North American continent is the breeding ground for these cycles. It's a region where climate and the ice's effect on the Earth's crust play off each other to draw out the length of a glacial cycle triggered by changes in solar radiation that come with changes in Earth's orbit.
This feedback between climate and ice becomes most dramatic at the end of the cycle, when an ice sheet that has bulldozed its way too far south and gotten too heavy for its own good meets up with a warming climate.
(Excerpt) Read more at csmonitor.com ...
I blame G W Bush!
HA! They are asking us to believe that the sun actually has some sort of impact on our weather??? Everyone knows this is not the case. The only thing that ever affects the weather is man's release of CO2
Yeah, who would even suppose the little ball of fire up there in the sky would have any affect on the temperatures on the planet...no, let’s seek a reason for climate change which we cannot see or measure.
I'm thinking that a law of Thermodynamics is being violated here with orbital paths oscillating despite no energy change being recorded.
They need to add increased volcanic activity, and its related effects, into their simulations. They might be surprised how much effect that alone would have.
“again and again/they promise the moon/they’re always coming and going and going and coming.”
Professor Von Schtup
The earth’s orbit and tilt are far form stationary.
Says it better than I can.
... and cow farts, dontchaknow.
That's okay, we've got big shoulders, we can take it.
Paging Algore. Paging Algore. Please pick up the white phone in the lobby.
I’m OK with orbits which are essentially eccentric. Up until Kepler, the orbits were expected to be perfect circles. Then Kepler showed that they were elliptical. Then we found out they were basically elliptical, but eccentric.
It just seems to me — and maybe I’m wrong — that if ice buildup were to increase the eccentricity, I do not see how a return to relative stability would be achieved. I would expect greater and greater degrees of eccentricity.
It goes hand in hand with ice shelves calving. The weight of the ice forces the shelf farther and farther out to sea. The ice flows. Eventually simple strength of materials tell us that the shelf is going to break off. I’m always amazed at the doomsayers who seem to think it should continue to the equator.
Ice on land is different but the same. The sheer weight forces it to flow. Eventually another force, temperature, is going to prevent the ice from covering the globe. It might be interesting for scientists to study what affect the increase in freshwater runoff has on climate.
I found the article to be a bit confusing. Are the changes in orbit because of the weight of the ice sheet, or does the ice sheet just melt faster due to the changes in orbit, aided by its gargantuan weight?
Other than that, the climate warmed all by itself? No man made intervention??? Shocking!
The rain forests cause more CO2 than North American continent.
Ice build up does not affect orbital eccentricity, nor substantially affect axial tilt or orientation. An ellipse with an eccentricity of 0.0 is a circle. The solution to the two body problem in Newtonian mechanics is conic section: orbits are either ellipses (a circle being a special case), parabolas or hyperbolas. For bodies which are graviationally bound (specific orbital energy < 0) they are ellipses, for bodies not gravitationally bound (soe >0) they are hyperbolas. For the case of soe = 0, parabolas.
There is a really nice introduction to orbital mechanics, by Bates, Mueller and White, “Introduction to Astrodynamics”, if you are interested.
1960's-era "World Book" encyclopedias contain references to ice floes the size of Delaware; giant floes/bergs are by no means a modern phenomenon.
Introduction to Astrodynamics
It’s rare to encounter a reference to that book. Where’d you run into it?
“Fundamentals”, could have been called introduction. It’s pretty much on an advanced undergraduate level. Somewhat dated, but a solid and gentle introduction.
I know all that; I’ve got a copy. ;-)
I was wondering how it came to your attention.
They tried to work CO2 into the mix for political reasons. It did not work. I would say based on this type of work 50% of the study is right and 50% is wrong.
This whole theory and the article has to be untrue.
Everyone knows that all climate change is caused by humans and most importantly by the actions of George Bush during his 8 years in office.
He is a genocidal maniac and will be responsible for the death of untold millions and the ruination of miles of seashore estates of the rich and famous unless we immediately listen to ALGORE and the OBAMABOTS
I had a similar feeling. The ice ages and global warming are all America’s fault /s
I couldn’t find an estimate based on their model - when is the next ice age supposed to start?
Were I work, it was a common reference in the 1980’s. It was either Bates, Mueller & White, or Pedro
Ramon Escobal. http://www.amazon.com/Methods-Orbit-Determination-Pedro-Escobal/dp/0882753193
Don’t know about “ice age”, but based on observations of the sun’s magnetic activity, expect the earth to be noticably cooler within the next decade.
I ran into it as the textbook for a course I took in college; the authors were members of the faculty.
Small institution in Colorado Springs? The book was something of an industry standard for folks who only needed to understand the basics. Not space mission planners, but the folks designing sensors like radar.
A little trade-school at the base of the Rocky Mountains.
Yeah, worked with some of its alums. Good crew, hardly a bad egg among them.
With a few notable exceptions.
“Mikey” Weinstein, as an example.
I was speaking only from personal experience.
At least they admit CO2 has not been driving the cycles. I’ve actually had alarmists argue that with me despite the fact the ice core data clearly show CO2 levels are a lagging factor.
But let’s not forget the probable North American boloid(s) around 13,000 years ago that may have caused the Younger Dryas. I suspect there are no simple or single answers. SC, time to post the Firestone et al book.
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