Dear IrishRockhound;
It is obvious that if there was a global flood, it occurred in connection with a rapid deglaciation event at the end of the last ice age. What probably happened was there was a large impact event on one of the large ice sheets that released enough water into the sea to raise the world sealevel by few feet or more. At the close of the last Ice Age, even a small rise in sea level may have been enough to destabilize the edges of the then existing Ice sheets. The impact event only had to cause a large enough sea level rise to trigger the surging of a few coastal edges of the Ice Sheets, which would raise sea level further which would cause more surging in a positive feed back chain reaction, a domino effect of rising sea level and glacial surging.
I agree with you entirely that melting todays glaciers would not be anywhere enough water to flood the world, you need to consider the glacial ice volume at the LGM (Late Glacial Maximum). The much larger ice volumes in existence at that time would of had much greater impacts on sea level rise then the mere Ice Age left overs we have today. It would be expected that large scale removal of water from the oceans durning the ice age would cause the ocean floor to rebound which would cause a general subsidence of the continents. This reduction in relief combined with glacial covering of the high points beneath glacial ice, may have allowed the entire earth to be covered by 'water' if the sea level rise reached the edges of the ice sheets and mountain glaciers before Hydroisostatic adjustment could compensate for the shift in weight.
On the Pleistocene Extinctions which occurred at the end of the ice age, I am greatly encouraged by the new reports that are beginning to show that many of the extinctions occurred in narrow time windows, of course I am disappointed that the windows don't all line up. But previously the extinctions have generally been viewed as happening progressively over a long period of time towards the end of the Ice Age. This newer view will no doubt be a major blow for the over hunting theory, while sudden climate change theories will have gained more support. A global flood would certainly be a sudden climate change, the differences in the timing of the events may become more alined with more research in the future. I don't view the dates as cast in stone, I think we will see some shifts yet on when these events happened. I also allow for preflood extinctions due to climate change and other effects and I allow for post flood extinctions as well. Perhaps some areas had high rates of local survival which couldn't handle the post flood climate in the long term. Wangel Island probably represents an isolated group of survivers who managed to survive for quite some time after the flood, sort of a Lost World, or a simple dating error.
Hydroisostasy, the continents sank beneath the ice and the oceans rebounded. Water is only one third the weight of rock, but with Hydroisostasy you get to count it twice since you are using it twice, one in the sea by removing it and once on the land by placing it. That is a lot of displacement.
Glaciers & Glaciation by Douglas I.. Benn & David J.A. Evans,1998 Oxford University Press Inc., On pages 29-30 states.
"This concept of hydroisostasy suggests that oceanic crustal up lift may occur during glaciations when large volumes of water are locked up in continental ice sheets, and that the return of this water during deglaciation will result in the redepression of the oceanic crust. Very few data are available on the amount and rate of hydroisostatic responses to glacial cycles, and the concept of sea floor rebound due to water unloading has been challenged by Morner (1987). some studies have inferred post-glacial hydroisostatic depression of the crust (e.g. Hopley, 1983, for Queensland, Australia), although estimates of the amount of ocean floor depression vary considerably, which is not surprising given the scattered study sites. Given the paucity of data, it is of no surprise that estimates of hydroisostatic impacts on global sea-level histories are mostly available only in geophysical models (e.g. Clark et al., 1978; Clark, 1980). . . . More accurate sea-level data can be obtained from the distribution of marine sediments, which can be identified using microfossils such as diatoms."
Hydroisostasy is according to this book, is challenged by some and does not have a lot of supporting data, so it is not possible to dismiss it as a minor effect of no real significance since not enough is known about at this time to do so. Marine diatoms can be used to chart sea-level changes, that is what I am doing. If I can accurately document the extent of late ice age marine diatoms far inland, I would have proof of a massive late ice age marine transgression and strong evidence of hydroisostatic influenced sea-level rise.
Studies In Geophysics; Sea-Level Change, Geophysics Study Committee commission on Physical Sciences, Mathematics, and Resources National Research Council, National Academy Press, 1990.
"Estimates for ice-volume sea-level equivalent tied up in equilibrium ice sheets range from as high as 163 m to as low as 102 m. Importantly, all of these calculations presume the ice sheets were at equilibrium."
Just using their figure of a possible 163 m, you would have a drop in the shoreline of only 54 m since the sea floor has rebounded 54 m and the continent has sunk 54 m. A sudden return of the water to the sea all at once would result in a flood 108 m above the then existing shoreline flooding a continent with a reduced relief due to the flatten effect of the weight of glacial ice. This flood would be a temporary flood as the shift in water would cause a very rapid hydroisostatic adjustment. Now the low stands for ice age shorelines are much lower than 54 m, which indicates a greater LGM ice volume than has been estimated. Such as the figure of 120 m, if that was hydroisostatically compensated for as it undoubtedly was, there would have been a 240 m flood above the ice age sea-level. With the reduced ice age relief, maybe that would have been enough to reach the now existing 1000 ft contour line, but if the marine diatom layer is mapped to even higher levels as it probably will, the rise of sea-level in the flood was probably higher. As the extent of the marine diatom layer is mapped to higher and higher elevations, it maybe a challenge for existing models of ice age sea-level and ice volume to explain. If such results are documented it will be interesting to see the impact on future scientific papers on the subject.
For further information I would suggest reading my book "Solving the Mystery of the Biblical Flood" available at
https://www1.xlibris.com/bookstore/bookdisplay.asp?bookid...
Sincerely Yours; Wm Scott Anderson
{Edited to add the "(Late Glacial Maximum)" to the subtitle. I'm curious to find out if this will carry through the chain of replies. - Adminnemooseus}
This message has been edited by Adminnemooseus, 09-19-2004 11:23 PM
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