Antarctica

HELEN
Precipitation (water in any form from the sky) happens due to two main things -- first it must be warm enough to evaporate and collect, thus forming clouds. Then it must be cooled enough to condense and fall, thus rain and snow.

We have incredible amounts of snow and ice in Antarctica. I've been spending part of the past hour looking over the new National Geographic, which has a couple of articles on Antarctica. It is the dryest continent on earth. If it were not ice, it would be desert. So how did all that ice get there? It could not have happened slowly, or it would have evaporated in such a dry climate. It had to happen quickly.

There are two possible creation models for this:

1. The basic traditional Flood model: the waters of the Flood which burst from the deep were hot. This set up an enormous amount of evaporation which initially fell as forty days of rain. Near the end of the Flood year, continuing volcanism sent more vapor into the atmosphere, which circulated around the world. As it fell in the cooler climes as snow, storm upon storm added up quickly to form the ice sheets at the South and North Poles.
However once the catastrophic year was over, the amount of moisture in the atmosphere leveled out and, with few discrepancies, the patterns of weather that we know today were established. Thus, while it no longer snows enough to build up the ice sheet at the South Pole, it did once.

2. The multi-catastrophe model: In this model the build-up of the Antarctic ice cap would have happened due to one of the catastrophes (or several) following Noah's Flood. It was probably in large part due to the catastrophic splitting of the continents in the time of Peleg as the mid-Atlantic rift literally unzipped admist the ongoing resultant volcanism of the Pacific Rim and the Mediterranean in particular. This also would have sent billions of tons of vapor into the atmosphere which would have precipitated over the colder regions of the poles, again in storm after storm while the world's climate settled down.

On pages 27 and 31 of the new NG (there are pictures on the in-between pages, the quote is continuous), there is an interesting passage:

"Looking over meteorological records going back to 1903, we are seeing a gradual warming trend here since the 1940's," Trivelpiece said. "NOAA satellite images also record a pronounced change in the cycle of winter sea ice since about 1970. Instead of consistently extensive winter pack we are now getting maybe two good years followed by up to five warm, ice-free winters. No ice means no food for the young krill. What we are seeing here is the first evidence of how a shift in climate may have a surprisingly quick and dramatic impact."

This caught my eye not because of the evidence of warm years vs. cold years, but because of the rapidity of the shift in the ecosystems. This may very well what we are seeing in the fossil record -- that the dramatic changes of environment after each of the major catastrophes (Flood, Babel, and Peleg) led to radically different predominances of life forms.

In the geologic record, we seem to have four major divisions: archaeozoic, proterozoic, mesozoic, and cenozoic.
Could these represent eras of predominant life forms in rather short order?

I am convinced that the scalding waters of Noah's Flood along with the massive explosions of material pulverized in them could not have fossilized anything -- well, maybe a few little organisms in the muds. But the fossilization which depends on mineralized waters and rapid drainage would have happened more in between the major catastrophes along the geologically active areas, such as the plate boundaries. Human beings and most mammals are not comfortable living in geologically active areas, and thus we simply do not find their fossils before the mesozoic (a few -- probably burrowing -- mammals) and cenozoic. Even then, their fossils are sparse, especially when compared to marine fossils, which would have been the first and majority fossilized in the plate boundary conditions.

Just some thoughts...

As I re-read this before posting, another thing came to mind and made me laugh. Humans are more than willing to live in geologically active areas today. This could be due to one or more of a couple of reasons:

1. Money. Coastal areas are areas of trade -- imports/exports -- and therefore man is willing to risk it.

2. Geological activity today 'ain't what it used to be.' So while there is still danger, it is much reduced.

3. Men are basically not as smart/intelligent as their ancestors.



MR BEN
Unfortunately your assertion is based on an incorrect assumption. The amount of evaporation in the very very cold air of antactica is quite low. Though the amount of precipitation in central antactica is around an inch a year, the amount of evaporation is a small fraction of this.


HELEN
This is true in the center of Antarctica, but not around the perimeter, where both calving of ice bergs and evaporation take quite a toll on the ice cap.

The rate of evaporation here figures to about an inch a year: http://tea.rice.edu/smith/12.1.1999.html

Here is another reference: http://www-das.uwyo.edu/~geerts/cwx/notes/chap10/continents.html

I also found the article here -- http://naturalscience.com/ns/articles/01-06/ns_clh.html -- interesting. However it was extremely hard to find hard data on the evaporation rates at different areas of Antarctica and after almost a hundred webpages quickly checked, I'll leave it to others who may know where better to go.


DOC
I looked at the websites you referred to. The first gives the evaporation rate for a pan of water at an average temperature of 63F. Most curious, that 63F. I wonder how she managed it. The second gives a precipitation rate of 110 mm/year and an evaporation (sublimation) rate of 10 mm/year. The third says it will probably snow more in Antartica as the world warms up. I don't see anything here that would buttress your hypothesis that unless the ice were deposited rapidly it would have sublimated faster than it was deposited.

You missed a few pages relevant to your hypothesis of rapid buildup, incidentally. Here is one. http://www.cs.colorado.edu/~lindsay/creation/icecap_synch.html


JAYCWRU
Actually ice does evaporate (actually sublimate) at cold temperatures. However it does so at a much slower rate than liquid water. Basically the rate water or ice dissapates into the atmosphere is proportional to its vapor pressure. Pulling my thermodynamics book up, I find that:

At 70ºF liquid water has a vapor pressure of 0.3632 psia. At 20ºF (probably a fairly conservative temperature estimate for Antartica), the vapor pressure of ice is 0.0505 psia. That means you could expect the evaporation rates would differ by a factor of 7.