Was There Ever Really An Ice Age?

[KNOWTHIS]

At least as it has been generally explained to have occurred. I have my doubts.

Of course there have always been areas of the earth with colder climates but was there really an Ice Age as a result of some kind of cycle? I’m beginning to wonder and here’s why. Could it have instead been caused by a major catastrophic event?

The remains of a Woolly Mammoth that was excavated in Siberia.

www.talkorigins.org/faqs/mammoths.html

"Its death must have occurred very quickly after its fall, for we found half-chewed food still in its mouth, between the back teeth and on its tongue, which was in good preservation. The food consisted of leaves and grasses, some of the later carrying seeds. We could tell from these that the mammoth must have come to its miserable end in the autumn."

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Because of the circumstances I really don't see it being caused by a gradual cycle, rather an instantaneous external, cataclysmic event. Especially since the plant in its mouth was evidence of the autumn period at the time of death. It's like finding a person frozen in ice in the process of eating half a cheeseburger. He obviously didn't even have time to react. Not at all consistent with the effects a slowly progressing cyclical event. Just my opinions as always.


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Here are some possible explanations. In bold is what I'm leaning towards now.

What caused the ice ages? There have been many explanations proposed, none of which appears to be solely adequate. These include:

1. Variations in the earth's orbital characteristics (angle of the ecliptic, eccentricity of the orbit, precession of the equinoxes). While this is sometimes touted as being "the" explanation of the ice ages, it cannot be the sole explanation since there have been long periods without glaciation during which Earth's orbital elements matched those of recent glacial periods. The patterns of ice advance and retreat DURING an ice age do seem to track the variations in orbital characteristics.

2. Excessive volcanic activity -- perhaps resulting from impacts of meteors, asteroids, or comets; or perhaps associated with the collision of detached land masses with continents proper (e.g., India with the rest of Asia).

3. Meteoritic and/or cometary impacts resulting in a kind of "nuclear winter." This includes the possibility of regular comet showers caused by a distant unseen solar companion (often called "Nemesis") deflecting outlying cometary bodies into the inner solar system.

4. Passage of the solar system through interstellar dust clouds as the solar system moves up and down through the plane of the galaxy.

5. "Fast" slippage of the earth's crustal plates on the underlying magma, perhaps caused by imbalances in the distribution of ice on continental surfaces. (This no longer appears to be a viable theory.)

6. Variations in solar output. Perhaps the sun is a long-period irregular variable star.

7. Changes in ocean currents and temperatures caused by shifting continental configurations.

[KNOWTHIS]

www.unexplainable.net/artman/publish/article_887.shtml

Australian Meteor Impact Might Have Caused the Ice Age

Evidence Of Meteor Impact Found Off Australian Coast

An impact crater believed to be associated with the "Great Dying," the largest extinction event in the history of life on Earth, appears to be buried off the coast of Australia.

NASA and the National Science Foundation (NSF) funded the major research project headed by Luann Becker, a scientist at the University of California, Santa Barbara (UCSB). Science Express, the electronic publication of the journal Science, published a paper describing the crater today.

Most scientists agree a meteor impact, called Chicxulub, in Mexico's Yucatan Peninsula, accompanied the extinction of the dinosaurs 65 million years ago. But until now, the time of the Great Dying 250 million years ago, when 90 percent of marine and 80 percent of land life perished, lacked evidence and a location for a similar impact event.

Becker and her team found extensive evidence of a 125-mile-wide crater, called Bedout, off the northwestern coast of Australia. They found clues matched up with the Great Dying, the period known as the end-Permian. This was the time period when the Earth was configured as one primary land mass called Pangea and a super ocean called Panthalassa.

During recent research in Antarctica, Becker and her team found meteoric fragments in a thin claystone "breccia" layer, pointing to an end-Permian event. The breccia contains the impact debris that resettled in a layer of sediment at end-Permian time.

They also found "shocked quartz" in this area and in Australia. "Few Earthly circumstances have the power to disfigure quartz, even high temperatures and pressures deep inside the Earth's crust," Becker said.

Quartz can be fractured by extreme volcanic activity, but only in one direction. Shocked quartz is fractured in several directions and is therefore believed to be a good tracer for the impact of a meteor.

Becker discovered oil companies in the early 70's and 80's had drilled two cores into the Bedout structure in search of hydrocarbons. The cores sat untouched for decades. Becker and co-author Robert Poreda went to Australia to examine the cores held by the Geological Survey for Australia in Canberra. "The moment we saw the cores, we thought it looked like an impact breccia," Becker said. Becker's team found evidence of a melt layer formed by an impact in the cores.

In the paper, Becker documented how the Chicxulub cores were very similar to the Bedout cores. When the Australian cores were drilled, scientists did not know exactly what to look for in terms of evidence of impact craters.

Co-author Mark Harrison, from the Australian National University in Canberra, determined a date on material obtained from one of the cores, which indicated an age close to the end-Permian era. While in Australia on a field trip and workshop about Bedout, funded by the NSF, co-author Kevin Pope found large shocked quartz grains in end-Permian sediments, which he thinks formed as a result of the Bedout impact. Seismic and gravity data on Bedout are also consistent with an impact crater.

The Bedout impact crater is also associated in time with extreme volcanism and the break-up of Pangea. "We think that mass extinctions may be defined by catastrophes like impact and volcanism occurring synchronously in time," Becker said. "This is what happened 65 million years ago at Chicxulub but was largely dismissed by scientists as merely a coincidence. With the discovery of Bedout, I don't think we can call such catastrophes occurring together a coincidence anymore," she added.