Posted on 04/30/2006 4:35:48 PM PDT by blam
Ice Ages Blamed on Tilted Earth
By Michael Schirber
LiveScience Staff Writer
posted: 30 March 2005
In the past million years, the Earth experienced a major ice age about every 100,000 years. Scientists have several theories to explain this glacial cycle, but new research suggests the primary driving force is all in how the planet leans.
The Earth’s rotation axis is not perpendicular to the plane in which it orbits the Sun. It's offset by 23.5 degrees. This tilt, or obliquity, explains why we have seasons and why places above the Arctic Circle have 24-hour darkness in winter and constant sunlight in the summer.
But the angle is not constant – it is currently decreasing from a maximum of 24 degrees towards a minimum of 22.5 degrees. This variation goes in a 40,000-year cycle.
Earth's Wobble ...
.
... is like the precession of a spinning top.
IMAGE: NASA
Peter Huybers of Woods Hole Oceanographic Institution and Carl Wunsch of the Massachusetts Institute of Technology have compared the timing of the tilt variations with that of the last seven ice ages. They found that the ends of those periods – called glacial terminations – corresponded to times of greatest tilt.
"The apparent reason for this is that the annual average sunlight in the higher latitudes is greater when the tilt is at maximum," Huybers told LiveScience in a telephone interview.
More sunlight seasonally hitting polar regions would help to melt the ice sheets. This tilt effect seems to explain why ice ages came more quickly – every 40,000 years, just like the tilt variations -- between two and one million years ago.
"Obliquity clearly was important at one point," Huybers said.
Colder planet
The researchers speculate that the glacier period has become longer in the last million years because...
(Excerpt) Read more at livescience.com ...
But wouldn't all that extra moisture in the atmosphere tend to act as a braking mechanism? No, wait! The weather pattern moves faster than the earth revolves, therefore, it would have an accelerating effect, pulling the earth along a little faster. Then when the next ice age occurs, all the water freezes and slows the planet down because it weighs more, right? Okay, I'm a believer. Science is sooooo easy to understand. :>
That's because "these idiots", unlike you, understand celestial mechanics, and why it's far more predictable over vast periods of time than nonlinear systems like the weather.
Perhaps you ought to educate yourself on the relevant topics before you make any further judgments on who's really an "idiot" and why.
Sorry, you have an invalid conclusion there.
First, while the general cycle of ice ages can be correlated with the Earth's tilt, it's hardly the only factor, nor does this article claim it is.
Second, you have overlooked the fact that any analysis of factors affecting conditions in the Earth's past can not necessarily be extrapolated to post-industrial periods, because there are new factors at work -- namely, the works of man.
For one example, studies of factors affecting the flow of the Colorado River over the past hundred thousand years would hardly "disprove" that it's possible to reduce it to a trickle of its former volume by building concrete dams, as has been done in past decades. And yet, your same line of "reasoning" could be employed to (fallaciously) argue such a case.
which means that short of figuing out a way to change the earth's tilt one way or another, there's not much we can do about it either way!!!
Wrong, since again, we are capable of engineering solutions which are unlike any of the natural factors which had previously affected climate before man came along.
Which means the liberal moonbats are full of it!!!
They may be, but you haven't managed to prove it by your faulty line of reasoning.
dr_lew is Correct. The Gregorian Calendar is tied to the solar cycle, but it "loses" about a one day every 3,000 years. The Gregorian cycle is 400 years, it was designed to correct the Julian Calendar which gained about three days every 400 years.
The author's assertion only makes sense for a civilization using a sidereal calendar, one which tied dates, like "January 1", to the position of the Sun against the celestial vault.
The length of day and period of the solar cycle are not any fixed ratio and may change in the next 30 centuries. If our ancestors so choose, they can adjust the calendar, like Pope Gregory did, to keep the end of the calendar year near the December solstice.
Other calendars (Chinese, Persian) are directly tied to the solar cycle.
Geez, the author can't even get his uniformitarian points right! Every non-catastrophist book I have ever read suggested that there were four ice ages over a 2 million year period. That averages out to one every 500,000 years, not 100,000.
These so called experts continue to ignore the impact that Mikkos Cassadine's evil weather machine had.
We need Washington to pass a law!
Actually, someone has mentioned that to me before. The weather patterns are from west to east and all the moisture would precipitate out on the western edges of the continents, or something like that...anyway.
Such as?
While ignorance may be curable, your arrogance and condescension is not.
"Why Speculate?", a speech by Michael Crichton (all of the speeches on his site).
:')
Hah!
When Ice melts, it becomes More dense. This would result in a slowing earth, longer days. But I’m sure Congress will save us.
This is really simple stuff. It’s as obvious as day and night, as are the impacts of variations in solar radiation (sunspot cycles), ocean currents, etc. But for some reason all those Great Scientists serving on the U.N. Intergovernmental Panel on Climate Change don’t seem to (care to) grasp it. Maybe we need to purge our universities and get back to teaching real science again instead of Marxist P.C.
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