View Full Version : Last Glacial Maximum not that glacial?


Andre
02-04-06, 12:55 PM
Let's bust another myth, the Last Glacial Maximum.

So what might that be?

http://en.wikipedia.org/wiki/Last_Glacial_Maximum

The Last Glacial Maximum refers to the time of maximum extent of the ice sheets during the last glaciation, approximately 21 thousand years ago. At this time, all of Northern Europe, almost all of Canada and the northern half of the West Siberian Plain were covered by huge ice sheets extending roughly to the southern boundary of the Great Lakes in North America and to a line from the mouth of the Rhine River through Kraków, Moscow up to the mouth of the Anabar River in Russia.

Ice sheets covered the whole of Iceland and all but the southern extremity of the British Isles, whilst the Patagonian Ice Sheet covered southern Chile down to about 41 degrees south. Ice sheets also covered Tibet ( it is still discussed between scientists worldwide, whether the Tibet Plateau was totally covered with ice, or there were only larger glaciers than today), Baltistan, Ladakh and the Andean altiplano. In Africa, the Middle East and Southeast Asia, many smaller mountain glaciers formed, especially in the Atlas, the Bale Mountains, and New Guinea.

The Ob and Yenisei Rivers had their flows stopped by the vast ice sheets, creating huge lakes....etc...etc

Apparantly the big big chill. But, wait until we're finished with it.

protostar
02-04-06, 02:55 PM
Yes interesting to add that about 20,000 yrs ago the last glaciation of the midwest usa extent also coincided with the POSITION CHANGE OF THE EARTHS PERIHELON AND APHELION! That is probably important to scientists.
was that a SOLAR REVERSAL? Also, in my research give or take a thousand years it also coincides with the ending/beginning of a GREAT YEAR.
25,920 earth years. hmm. and guess what, this last great year which is
solar cycle #23 ends december 2012.
Also, if the geomagnetic poles which are aligned with the axis of the core
(polaris center) now that the north geomagnetic pole has wandered
tpw tru polar wander to the west, is the axis "offline"?
what's your thoughts?

Andre
02-05-06, 05:32 AM
No I guess it would not make much sense to disdain the work of hundreds of geologists to haunt some vague ideas. No we need to do some studing first like this:

http://www.ngu.no/FileArchive/102/Bulletin438_3.pdf

and several hundreds more

Xylene
02-05-06, 08:18 PM
The sealevel was about 120 metres lower than now 20,000 BC. That sounds pretty glacial to me. :cool:

Andre
02-06-06, 04:59 AM
But there are 10 skeletons of Beluga's found in situ and in anatomical order on the northernmost land on Earth, Severnya Zemlya, or the October revolution islands on an elevation of 120 meters. Dating is beyond carbon horizon, so older than 50,000 years but the bones are not mineralized which suggest not that much older. Perhaps Eemian (ca 120,000 years, perhaps younger) But it reveals that both the sea level was not that obvious and that that part of the World did not glaciate ever since 50,000 years ago.

The Dutch caption about this vertebra reads pretty much the same as I narrated:

http://home.wanadoo.nl/bijkerk/vertebra.JPG

river-wind
02-06-06, 11:54 AM
is the idea that glaciation of the area would have mangled the arrangement of the bones? What if the sediment uplift brought them to that elevation after glaciers melted away?

Andre
02-06-06, 12:13 PM
A glaciation would clean up the area thoroughly, only bedrock or flat sediment to stay behind. Yes isostatic post-glacial rebounce is a possible explanation for that sea level lowering but not necasarily so. There have been other unexplained uplifts like this (http://www.gsajournals.org/gsaonline/?request=get-document&doi=10.1130%2F0091-7613(2002)030%3C0379:BIBTSW%3E2.0.CO%3B2) for instance.

Andre
02-07-06, 08:40 AM
This standard work about the Latest Pleistocene glaciation period,

Hubberten HW et al (2004), The Weichselian in Eurasia ( The periglacial climate and environment in northern Eurasia during the Last Glaciation Quaternary Science Reviews 23 (2004) 1333–1357)

shows three distinct glacial maximums in Eurasia, 90 Ky 60 Ky and 20 Ky ago.

http://home.wanadoo.nl/bijkerk/weichselian.JPG

Now there are several things to wonder about, I guess.

river-wind
02-07-06, 11:24 AM
andre, what's the source on those maps?

If they are not your own, then I'd say they are pretty darn supportive of your Wandering Poles theory RE: ice ages.

Andre
02-07-06, 12:29 PM
Here it is. Source (http://www.hi.is/~oi/PDF%20reprints/Svendsen%20et%20al%20-%20Late%20Quaternary%20ice%20sheet%20history%20of% 20northern%20Eurasia.pdf)

Seems rather obvious isn't it. But there is a lot more.