Spirituality
03 Dec 09
08 Dec 09
Originally posted by Proper KnobHere it is again........I did post it but it didn't stay on the forum. Don't know why???
[b]And I've answered you twice now about the ice caps
Galvo, you haven't answered anything about the ice caps. You are still yet to produce any evidence to support your unsubstantiated view that the ice caps are only 5,000yrs old. Last night when i asked you, your reply was 'still working on it'. I can only conclude that after checking every websi ...[text shortened]... ago. Robbie has yet to do it after numerous requests, maybe you'll have better luck!![/b]
The Visual Method od dating ice...
But how, exactly, are these layers counted? Obviously, at the surface the layers are easy to count visually – and in Greenland the layers are fairly easily distinguished at depths as great as 1,500 to 2,000m (see picture). Even here though, there might be a few problems. How does one distinguish between a yearly layer and a sub-yearly layer of ice? For instance, it is not only possible but also likely for various large snowstorms and/or snowdrifts to lay down multiple layers in a given year. Very short-term oscillations representing as little as a day or two do show up as variables in the layers of ice.6 Storms can vary in their temperature patterns. They can also last a few hours to several days, weeks, or even months. Of course, these storms and other anomalous weather patterns might present a bit of a problem for the uniformitarian paradigm. Consider the following excerpt from a 1997 issue of the Journal of Geophysical Research:
“Fundamentally, in counting any annual marker, we must ask whether it is absolutely unequivocal, or whether nonannual events could mimic or obscure a year. For the visible strata (and, we believe, for any other annual indicator at accumulation rates representative of central Greenland), it is almost certain that variability exists at the subseasonal or storm level, at the annual level, and for various longer periodicities (2-year, sunspot, etc.). We certainly must entertain the possibility of misidentifying the deposit of a large storm or a snow dune as an entire year or missing a weak indication of a summer and thus picking a 2-year interval as 1 year.” 7
Good examples of this phenomenon can be found in areas of very high precipitation, such as the more coastal regions of Greenland. It was in this area, 17 miles off the east coast of Greenland, that Bob Cardin and other members of his squadron had to ditch their six P-38’s and two B-17’s when they ran out of gas in 1942 - the height of WWII. Many years later, in 1981, several members of this original squad decided to see if they could recover their aircraft. They flew back to the spot in Greenland where they thought they would find their planes buried under a few feet of snow. To their surprise, there was nothing there. Not even metal detectors found anything. After many years of searching, with better detection equipment, they finally found the airplanes in 1988 three miles from their original location and under approximately 260 feet of ice! They went on to actually recovered one of them (“Glacier Girl” – a P38), which was eventually restored to her former glory.20
What is most interesting about this story, at least for the purposes of this discussion, is the depth at which the planes were found (as well as the speed which the glacier moved). It took only 46 years to bury the planes in over 260 feet (~80 meters) of ice and move then some 3 miles from their original location. This translates into a little over 5 ½ feet (~1.7 meters) of ice or around 17 feet (~5 meters) of compact snow per year and about 100 meters of movement per year. In a telephone interview, Bob Cardin was asked how many layers of ice were above the recovered airplane. He responded by saying, “Oh, there were many hundreds of layers of ice above the airplane.” When told that each layer was supposed to represent one year of time, Bob said, “That is impossible! Each of those layers is a different warm spell – warm, cold, warm, cold, warm, cold.” 21 Also, the planes did not sink in the ice over time as some have suggested. Their density was less than the ice or snow since they were not filled with the snow, but remained hollow. They were in fact buried by the annual snowfall over the course of almost 50 years.
Now obviously, this example does not reflect the actual climate of central Greenland or of central Antarctica. As a coastal region, it is exposed to a great deal more storms and other sub-annual events that produce the 17 feet of annual snow per year. However, even now, large snowstorms also drift over central Greenland. And, in the fairly recent warm Hipsithermal period (~4 degrees warmer than today) the precipitation over central Greenland, and even Antarctica, was most likely much greater than it is today. So, how do scientists distinguish between annual layers and sub-annual layers? Visual methods, by themselves, seem rather limited – especially as the ice layers get thinner and thinner as one progresses down the column of ice.
Oxygen and Other Isotopes:
Well, there are many other methods that scientists use to help them identify annual layers. One such method is based on the oxygen isotope variation between 16O and 18O (and 17O) as they relate to changes in temperature. For instance, water (H2O), with the heavier 18O isotope, evaporates less rapidly and condenses more readily than water molecules that incorporate the lighter 16O isotope. Since the 18O requires more energy (warmer weather) to be evaporated and transported in the atmosphere, more 18O is deposited in the ice sheets in the summer than in the winter. Obviously then, the changing ratios of these oxygen isotopes would clearly distinguish the annual cycles of summer and winter as well as longer periods of warm and cold (such as the ice age) – right? Not quite. One major drawback with this method is that these oxygen isotopes do not stay put. They diffuse over time. This is especially true in the “firn layer” of compacted snow before it turns into ice. So, from the earliest formation of these ice layers, the ratios of oxygen isotopes as well as other isotopes are altered by gravitational diffusion and so cannot be used as reliable markers of annual layers as one moves down the ice core column. One of the evidences given for the reality of this phenomenon is the significant oxygen isotope enrichment (verses present day atmospheric oxygen ratios) found in 2,000 year-old-ice from Camp Century, Greenland.3 Interestingly enough, this property of isotope diffusion has long been recognized as a problem. Consider the following comment made by Fred Hall back in 1989:
“The accumulating firn [ice-snow granules] acts like a giant columnar sieve through which the gravitational enrichment can be maintained by molecular diffusion. At a given borehole, the time between the fresh fall of new snow and its conversion to nascent ice is roughly the height of the firn layers in [meters] divided by the annual accumulation of new ice in meters per year. This results in conversion times of centuries for firn layers just inside the Arctic and Antarctic circles, and millennia for those well inside [the] same. Which is to say--during these long spans of time, a continuing gas-filtering process is going on, eliminating any possibility of using the presence of such gases to count annual layers over thousands of years.” 4
Lorius et al., in a 1985 Nature article, agreed commenting that, “Further detailed isotope studies showed that seasonal delta 18O variations are rapidly smoothed by diffusion indicating that reliable dating cannot be obtained from isotope stratigraphy”.29 Jaworowski (work discussed further below in "Biased Data" section) also notes the following:
The short-term peaks of d18O in the ice sheets have been ascribed to annual summer/winter layering of snow formed at higher and lower air temperatures. These peaks have been used for dating the glacier ice, assuming that the sample increments of ice cores represent the original mean isotopic composition of precipitation, and that the increments are in a steady-state closed system.
Experimental evidence, however, suggests that this assumption is not valid, because of dramatic metamorphosis of snow and ice in the ice sheets as a result of changing temperature and pressure. At very cold Antarctic sites, the temperature gradients were found to reach 500°C/m, because of subsurface absorption of Sun radiation. Radiational subsurface melting is common in Antarctica at locations with summer temperatures below -20°C, leading to formation of ponds of liquid water, at a depth of about 1 m below the surface. Other mechanisms are responsible for the existence of liquid water deep in the cold Antarctic ice, which leads to the presence of vast sub-sheet lakes of liquid water, covering an area of about 8,000 square kilometers in inland eastern Antarctica and near Vostok Station, at near basal temperatures of -4 to -26.2°C. The sub-surface recrystallization, sublimation, and formation of liquid water and vapor disturb the original isotopic composition of snow and ice. . .
Important isotopic changes were found experimentally in firn (partially compacted granular snow that forms the glacier surface) exposed to even 10 times lower thermal gradients. Such changes, which may occur several times a year, reflecting sunny and overcast periods, would lead to false age estimates of ice. It is not possible to synchronize the events in the Northern and Southern Hemispheres, such as, for example, CO2 concentrations in Antarctic and Greenland ice. This is, in part the result of ascribing short-term stable isotope peaks of hydrogen and oxygen to annual summer/winter layering of ice. and using them for dating. . .
In the air from firn and ice at Summit, Greenland, deposited during the past ~200 years, the CO2 concentration ranged from 243.3 ppmv to 641.4 ppmv. Such a wide range reflects artifacts caused by sampling or natural processes in the ice sheet, rather than the variations of CO2 concentration in the atmosphere. Similar or greater range was observed in other studies of greenhouse gases in polar ice.50
I have more if your interested???
08 Dec 09
Originally posted by galveston75I'll respond tomorrow.
Here it is again........I did post it but it didn't stay on the forum. Don't know why???
The Visual Method od dating ice...
But how, exactly, are these layers counted? Obviously, at the surface the layers are easy to count visually – and in Greenland the layers are fairly easily distinguished at depths as great as 1,500 to 2,00 ...[text shortened]... ed in other studies of greenhouse gases in polar ice.50
I have more if your interested???
Post the link where you got it please.
09 Dec 09
Originally posted by galveston75I've given it a little quick look through, but i can't find anywhere in the text which states that the ice caps are only 5,000yrs old.
Here it is again........I did post it but it didn't stay on the forum. Don't know why???
The Visual Method od dating ice...
But how, exactly, are these layers counted? Obviously, at the surface the layers are easy to count visually – and in Greenland the layers are fairly easily distinguished at depths as great as 1,500 to 2,00 ...[text shortened]... ed in other studies of greenhouse gases in polar ice.50
I have more if your interested???
09 Dec 09
Originally posted by galveston75I've asked this question many times in the past, but I'll ask you this time: what is it about evolution that bothers you so much? It is merely a scientific explanation for a particular phenomena. What is it about this explanation that bothers you so much?
"Revolution against Evolution"
09 Dec 09
Originally posted by Proper KnobIt isn't saying that. It's clearly saying that there are problems with dating the ice caps by just looking at core samples. I'll send more to read...
I've given it a little quick look through, but i can't find anywhere in the text which states that the ice caps are only 5,000yrs old.
09 Dec 09
Originally posted by amannionLots.....But the very basic one answer though is it is not where humans came from no matter how hard evolutionist try to convience us and themselves. Not one shread of evidence but yet they say it's fact.
I've asked this question many times in the past, but I'll ask you this time: what is it about evolution that bothers you so much? It is merely a scientific explanation for a particular phenomena. What is it about this explanation that bothers you so much?