Archaeologica.org

Which means they are are cluesless as me then Min. The only way I can see a sub surface lake forming is vulcanism.

Roy.

According to them Lake Agassiz was a meltwater lake sitting in the middle of an ice field! Now how is that possible?

Possibly what Firestone & Topping called a "thermonuclear event."

First, I think the calling of Lake Agassiz a “sub-surface” lake is a typo.
I have never seen it referred to that way before.
http://en.wikipedia.org/wiki/Lake_Agassiz

Secondly, given the right weather conditions it is possible to have melted water on top of a layer of ice.
I can look out my sons back window today at the lake he lives on and see puddles of water setting on about six inches of ice.

The process they are talking about is the same that we see every spring as the mountain glaciers start to melt.
The surface melts first but as it runs downhill it sometimes tunnels under the surface forming subsurface streams.
But those tunnels eventually collapse into crevices.
Those crevices allow more water to flow faster and pretty soon the “flood gates” are open.
And floods can move a lot of dirt around real fast.

I understand all that kb but according to the programme this lake wasn't just on the surface, it was a deep as the ice and contained hundreds of trillion of tonnes of water.

Roy.

Geologists seem pretty well convinced of this scenario.

http://www.pbs.org/wgbh/nova/megaflood/scab-flash.html


This is an interactive site from the Pacific Northwest. Floods went west as well as east.

The TV programme has the water draining into Hudson Bay and hence into the north Atlantic Min.

Roy.

Apparently the Amazon ran from east to west, and emptied into the Pacific, some millions of years ago. I wonder if that in any way coincided with any of the respective glaciation events. And not just 'coincided', but did it perhaps even affect what happened in the northern hemisphere at the time? Or vice versa.

uniface wrote:According to them Lake Agassiz was a meltwater lake sitting in the middle of an ice field! Now how is that possible?

Possibly what Firestone & Topping called a "thermonuclear event."

Here is my current working hypothesis. (Note carefully: I have been wrong in the past, and reserve the right to be wrong both now and in the future.)

During the Ice Age, the Pacific Current was warmer, leading to warm moist air over North America, leading to snow, leading sunlight being reflected back into space, leading to a cooler Earth. Something (like say an impact over North America, or several impacts somewhere on the planet) led to the Pacific Current cooling, leading to less warm moist air over North America, leading to less snow, leading to more sunlight being absorbed, leading to a warmer Earth.

Leading to melt water trapped under glacier?

Alternative: Or perhaps it was simply the heat generated by compression.

Alternative: heat generated by impact compression.

The sad part in all of this is that our science in general is so starved for funds that we can't even answer definitively a major question like this one. The funding for research on recent impacts is also insufficient.

Of course, there's the private sector. (I do offer a special on my book for you all, and it would make a great Christmas gift for anyone you know of Native American heritage or who is a North American field archaeologist. PM me.)

It would seem that the shut down of the Atlantic Current led to the Red Paint people crossing from Europe, RC's given at 8,350 BCE, with Dalton Maritime Archaic points appearing along with European diseases.

E.P. Grondine
Man and Impact in the Americas

It would seem that the shut down of the Atlantic Current

and that's another bone of contention with me EP as I cannot see any mechanism that could cause that to happen other than a breach in the Panamanian isthmus.

Roy.

Digit wrote:The TV programme has the water draining into Hudson Bay and hence into the north Atlantic Min.

Roy.

Yes, I know. But there is evidence for a westward flow as well as the Hudson Bay situation.

Digit wrote:It would seem that the shut down of the Atlantic Current

and that's another bone of contention with me EP as I cannot see any mechanism that could cause that to happen other than a breach in the Panamanian isthmus.

South and north America only connected/collided about 4 million years BP, afaik. Before that there was a wide gap between south and north America, an open connection between the Pacific and the Atlantic. So the 'conveyor belt' (global pelagic current system) probably ran an entirely different course before that 'collision', which would have made the climate zones look very different from today's too.

Very true RS and a point I am trying to hammer into a group of Al Gore's desciples.

Roy.

5 million years ago, we did not have to worry about climate change.

I've got a long memory!

Roy.