In Message 25 of 28 on
10-18-2003 10:55 AM, David wrote:
"I was fortunate to have heard a lecture
on this very topic a few weeks ago."
Whether you were "fortunate" depends on whether the speaker knew anything about was he was talking about. There are a number of Young Earth creationists speakers out there, i.e. Kent Hovind, Carl Baugh, Don Patton, to name a couple, who are functionally illiterate in understanding what they are talking about. They sound authoritative, but instead know nothing about what they are talking.
For example, go read:
1. Analysis of Kent Hovind
http://www.geocities.com/kenthovind/
2. Kent Hovind FAQs Examining "Dr. Dino"
Kent Hovind FAQs: Examining "Dr. Dino"
3. What About Carl Baugh?
A Commentary by Answers in Genesis
http://members.aol.com/paluxy2/whatbau.htm
4. The Carl Baugh Page
Account Suspended
Not all speakers know what they are talking about.
David then asked:
"It's easy to postulate that precipitation
in one area has been the same throughout
time, equal to what it is today. However,
doesn't the existence on one or more ice
ages negate that possibility?"
It is true that there will be some variation in accumulation rates through time. However, the variations in accumulation can be determined by the various ways of independently dating ice cores. For example, volcanic ash particles from volcanic eruptions known to have occurred in AD 1783 and AD 79 have been found ice cores in central Greenland. These volcanic ashes and other markers provide datum by which variations in accumulation rates over time can be detected and such assumptions either validated or corrected. As previously noted in another post this is discussed in "The Two-Mile Time Machine" by R. B. Alley.
Also, read "Ice Core Dating by Matt Brinkman" at:
http://www.talkorigins.org/faqs/icecores.html
David then stated:
"We presently don't have the conditions to
create an ice age of the proportions
evidenced by geological evidence of giant
boulders, and scratching of even some of
the hardest rocks."
That is why we are in an relatively "ice-free" interglacial stage instead of being in an full glacial epoch. If current conditions were the same as they were during the last glacial stage, the world be cold as heck and there would be continental ice sheets. This argument invokes an unrealistic hyper-uniformitarism, which infers that past environments must have observable modern analogues. However, the overall middle to late Tertiary global climatic cooling, orbital parameters, possibly even cycles in concentrations of interstellar dust, and other factors are present, which would have created another ice age had man-made factors not induced an artificial global warming.
David then stated:
"Large grooves were seen in one volcano
trunk. Only one of these grooves was
broken by a successive freezing of water
inside. If any ice age was very long ago,
the rest of those grooves would've been
broken."
Where is the evidence that these glacial grooves were created by continental glaciation associated with the last glacial stage? Many mountains have alpine (mountain) glaciers that persisted after the end of the last glacial stage. In fact some of these alpine glaciers advanced significance distances downslope at times well after the last glacial stage and even in historic times. These grooves being discussed could very well be of recent origin. In fact, they might have under ice since the beginning of the last glacial stage and now being exposed by rapid melting due to global warming.
Some web pages:
1. Reyes, A., and Smith, D. J., 2001, Tree-ring dates
for Neoglacial Lake Alsek, Yukon Territory, Canada.
Canadian Quaternary Association/ Association
canadienne pour l'etude du Quaternaire, Annual
Meeting 2001. Whitehorse, Yukon Territory,
August 20 - 24, 2001. at:
http://cgrg.geog.uvic.ca/abstracts/ReyesTree-ringLake.html
"Lake Alsek in southwestern Yukon Territory
formed several times during the
Neoglacial when Lowell Glacier advanced
across the Alsek Valley and blocked
southerly drainage of the Alsek River....
The last major lake phase ended sometime
between 1857 and 1891 and was preceded
by a ponding event that ended between
1788 and 1832. An earlier, more extensive
lake phase ended sometime after 1611.
These results suggest that Lowell Glacier
reached its maximum Little Ice Age position
at least 200 years earlier than several
other large valley glaciers in the
northeastern St. Elias Mountains."
The last major advance of this glacier was in 1857 and 1891 with another period of advance between 1788 and 1832.
2. REYES, Alberto V. nad others, 2003, TREE-RING
DATING OF LITTLE ICE AGE GLACIER ADVANCES
AND ASSOCIATED ICE-DAMMED LAKES IN KLUANE
NATIONAL PARK AND RESERVE, YUKON TERRITORY, CANADA.
Session No. 52, Glaciers, Glacial Geology, and
Glacial Ecosystems in the National Parks
2003 Geological Society of America (Seattle)
Annual Meeting (November 2-5, 2003) at:
http://gsa.confex.com/...3AM/finalprogram/abstract_67695.htm
"The ages of seven such stems, which we
dated by comparing their ring-width patterns
to a ~900 year tree-ring chronology from
nearby south Kluane Lake, suggest that
Kaskawulsh Glacier was at its most extensive
Holocene position in the early-mid 18th
century."
3. A Service of The Greening Earth Society
Little Ice Age a Global Event by Diane Douglas
Dalziel, Office of Climatology, Arizona State
University at:
http://www.greeningearthsociety.org/...cles/2001/hockey1.htm
David also stated:
"Isn't assuming there was only one
freezing and melting per year in a
glaciation area reaching a bit? A
storm followed by a melt would produce
one layer. Ice has been seen melting
in Antartica at 14F."
Given what is known about the climate of where the ice cores were taken, it is not reaching it a bit. Contrary to what the lecturer was apparently stating, I seriously doubt there is going to be a spring thaw in the middle of winter in the middle of northern Greenland. In the part of Greenland in which the ice cores came, they don't have "storms" in the sense that the lecturer apparently was talking about. All this lecturer was demonstrating was a lack of knowledge about the climatology of Greenland.
As far as ice melting at 14F, that temperature is -10C, which is a balmy July day for Greenland. What is unusual about ice melting in the summer?
An informal article about Greenland in the summer is "Unraveling Climate's Mysteries atop an Arctic Summit A visit to Greenland, where scientists at a polar lab focus on the ozone hole above and the ice below" at:
Bloomberg - Are you a robot?Bloomberg - Are you a robot?
Also, the layering in ice coring are defined by much more than simply a melting and freezing.
Then David commented:
"We can debate the precipitation in
Greenland vs. other areas, but the
fact remains that there was 75m of
ice deposited in 46 years in Greenland.
That's 5.35 ft/year."
We are not debating the precipitation of Greenland versus precipitation in other areas, i.e. Antarctica. We are primarily discussing the variation of precipitation **within** Greenland. It has been well documented that precipitation rates vary drastically **within** Greenland from over 5.4 ft/year (1.64 meters/year) along the southeast coast where the Lost Squadron crashed to less than 0.8 ft/year (0.25 m/year) at the GISP2 ice core site. The rate of accumulation at the Lost Squadron location is 625 percent that of the rate of accumulation at GISP2 ice core site. Given this difference, a person can't compare the depth of burial of the Lost Squadron with the accumulation of ice at the GISP2 site. It is like trying estimate how long it would take rainfall to fill up a newly dug pond in Lubbock, Texas using the rainfall rates for New Orleans, Louisiana
Anyway, these variations are discussed and illustrated in:
1. Bales et al. (2001a) snow accumulation map for Greenland
http://www-bprc.mps.ohio-state.edu/...racts/BALESGRLFIG5.jpg
2. Bales et al. (2001b) snow accumulation map for Greenland
http://www-bprc.mps.ohio-state.edu/...bstracts/BALESFIG3.jpg
3. Bales, R. C., McConnell, J. R., Mosley-
Thompson, E., and Csatho, B., 2001a, Accumulation
over the Greenland ice sheet from historical
and recent records. Journal of Geophysical
Research (Atmospheres). vol. 106(D24), no.33,
pp.813-33,825.
http://www-bprc.mps.ohio-state.edu/...tracts/bales-jgr-1.pdf
4. Bales, R. C., McConnell, J. R., Mosley-
Thompson, E., and Lamorey, G., 2001b. Accumulation
map for the Greenland ice sheet 1971-1990.
Geophysical Research Letters, 28(15), 2967-2970
http://www-bprc.mps.ohio-state.edu/...s/Bales2001GRL-Aug.pdf
5. PDF files of publications on Green land climatology
http://www-bprc.mps.ohio-state.edu/...stracts/Abstracts.html
6. Snow Accumulation at GISP2 Summit, Greenland
Page not found - The University of Maine
David commented:
"In an ice age, wouldn't you think
you could build up alot more ice?"
Yes, but doubling the rate from 0.25 meter/year to 0.50 meter/year wouldn't even begin to match the rate of accumulation at the Lost Squadron location. Climatic change doesn't operate in a nice linear fashion. Just because an ice age occurs doesn't mean that that there would be any large increase in accumulation rates. In fact, it is possible that in some parts of Greenland that glacial accumulation rates would be less than modern accumulation rates. Given the complex manner in how oceanic and atmospheric circulation patterns and associated precipitation patterns would differ from modern circulation and precipitation patterns, a person can't predict whether the glacial precipitation would either less or more than modern precipitation and by how much at any specific point by using only intution. A person would have to carefully model these changes using as much paleoenvironmental data they can get collect to answer this question for a specific location such as the GISP2 location.
Finally, David commented:"
A global flood, combined with extreme
volcanism (blocking out the sun's rays)
and mass evaporation after the flood,
could have resulted in an ice age lasting
about 700 years. Ocean volcanism would've
resulted in warmer oceans, increasing
precipitation."
The problem here is that there is neither the evidence of a global flood nor extreme volcanism having occurred just before the ice age. Enough deep sea cores have been collected from all around the world by the Deep Sea Drilling and Ocean Drilling projects to disprove the notion that anything above normal volcanism occurred during the last or any other glacial epoch. Finally, using foraminifer assemblages and oxygen isotope analysis of those foraminifer from deep sea cores, it is well known that during the glacial stages, sea weren't warmer as proposed above. In fact, they were either cooler or somewhat cooler during the glacial stages than they are now.
For example:
CLIMAP Last Glacial Maximum August Sea Surface Temperatures at:
views: CLIMAP LGM aug sstdata: CLIMAP LGM aug sst
CLIMAP Modern August Sea Surface Temperatures at:
views: CLIMAP MOD aug sstdata: CLIMAP MOD aug sst
Some examples are:
1. Pflaumann, U., et al., 2000, Glacial North
Atlantic: Sea-surface conditions reconstructed
by GLAMAP. Paleoceanography. vol. 18, no. 3,
pp. 1065-1072. at:
http://www.agu.org/pubs/crossref/2003/2002PA000774.shtml
2. Sachs, J. P., Anderson, B. F., Lehman, S. J.,
2001, Glacial surface temperatures of the
southeast Atlantic Ocean. Science. vol. 293,
pp. 2077-2079.
Page Not Found | MIT - Massachusetts Institute of Technology
3. Trend-Staid, M., and Prell, W. L., 2002,
Sea surface temperature at the Last Glacial
Maximum: A reconstruction using the modern
analog technique, Paleoceanography. vol. 17,
no. 4, pp. 1065-1069.
http://www.agu.org/pubs/crossref/2002/2000PA000506.shtml
"One of the most important results is the
2-6C mean annual cooling in the central
to eastern tropical Atlantic and up 8C
cooling in the eastern tropical Pacific."
Finally, almost any of the paleosols lying between sets of glacial tills, which I mentioned in my previous post, certainly took longer than 700 years to form. They alone certainly demonstrate that the Pleistocene Ice Ages, even the last glacial stage, lasted more than 700 years.
Yours,
Bill Birkeland
Texas.
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