Doggerland

Port

Ad Honorem
Feb 2013
2,100
portland maine
The thread on Atlantis brought to mind the discovery of Doggerland. A land mass from 18 thousand to – 5500 years ago that connected England to France and Scotland to Denmark and Belgium. A landmass that was exploited by hunter gatherers. From the early 1900’s fishing vessels have dragged up mammoth and lion remains as well as small number of prehistoric tools and weapons. University research has found evidence of a surprisingly advanced late Mesolithic fishing culture, including finely decorated canoe paddles and several long, thin canoes, one of them over 30 feet long. Another showed how diet changes from fresh water to marine animals. As the planet warmed the sea levels rose. Around 7 thousand years ago a “melt down of frigid water called the Storregga Slide triggered a tsunami flooding the northern coast of Europe. Then at 6 thousand years people on boats arrived on the British Isles with cattle goats farming technology. I was unable to find any information on animal migration patterns concerning Doggerland as a land bridge.
 

beorna

Ad Honoris
Jan 2010
17,473
-
Hamburger culture 13,7ky-12.2ky BCE


Federmesser culture 12-10-8ky BCE


Ahrensburger culture 10.7-9.6ky BCE
 

caldrail

Ad Honorem
Feb 2012
5,357
The thread on Atlantis brought to mind the discovery of Doggerland. A land mass from 18 thousand to – 5500 years ago that connected England to France and Scotland to Denmark and Belgium. A landmass that was exploited by hunter gatherers. From the early 1900’s fishing vessels have dragged up mammoth and lion remains as well as small number of prehistoric tools and weapons. University research has found evidence of a surprisingly advanced late Mesolithic fishing culture, including finely decorated canoe paddles and several long, thin canoes, one of them over 30 feet long. Another showed how diet changes from fresh water to marine animals. As the planet warmed the sea levels rose. Around 7 thousand years ago a “melt down of frigid water called the Storregga Slide triggered a tsunami flooding the northern coast of Europe. Then at 6 thousand years people on boats arrived on the British Isles with cattle goats farming technology. I was unable to find any information on animal migration patterns concerning Doggerland as a land bridge.
Meltwater did not cause a tsunami. The flooding of Doggerland would have inundated two miles a day on average given the geography and the extremely rapid warming of the climate.

However, there have been tsunami's afflicting Britain in the past, in one instance caused by a catastrophic collapse of coastal cliffs in scandanavia (a similar event in Alaska in recent times has demonstrated how powerful these incidents can be), and possibly the collapse of a natural wall holding an inland sea in prehistoric Canada (admittedly composed of meltwater and it was melting that caused the breach, but this was a catastrophic failure of the restraining feature in nature and not due to melting alone)

There was also a tsunami in the 17th century in the Somerset levels, caused byu an offshore earthquake, the normal cause of such things.
 

beorna

Ad Honoris
Jan 2010
17,473
-
it is difficult to say when exactly the storrega slide occured. But it seems, that they occured at the end of the doggerband as isle.
 
Dec 2009
918
The shallow water overlying continental shelves comprises several million cubic kilometers, or ~0.3% (one-third of one percent) of earth's oceanic volume. Those millions of gigatons of water were locked up in land glaciers. With a hypothetical space-elevator, perhaps water could be pumped out into orbit, for space farms, re-exposing ice-age continental shelves, for development, and archaeology. According to Wikipedia, simple graphene is strong enough, both in compression (for ultra-tall base towers, 1000s km high) and tension (for ultra-long cables, 10000s km long, from tower tip out to space), to build such systems. In scale model analogy, building a base tower, 1000s of km high, would resemble building the Eiffel Tower in Paris, from iron filings, born by bugs like ants. An ultra-tall scaffolding, built like a "geodesic termite mound", could withstand its weight, if the girders were constructed from graphene. Towers might be better able to withstand impact from high-velocity space dust, whirling around in low earth orbit. Then, graphene cables could then link the tower top, out to the space orbital platform, out where space dust swirls around more slowly.

If the current cost of orbiting payloads is currently millions of dollars per ton (and nearly nothing with a space elevator, comparable to the cost of a train ticket); and if a space elevator cost trillions of dollars; then the space elevator would be cost effective, if millions of tons of hardware was orbited. Space factories & space farms, as big as sky scrapers, would be required, to make a space-elevator ultra-hyper-super-project worthwhile.

To avoid being damaged in earthquakes, such ultra-tall towers would have to be built on a single crustal plate -- presumably the African plate (or, hypothetically, the Pacific plate) -- straddling earth's equator.
 

caldrail

Ad Honorem
Feb 2012
5,357
That would be folly of an incredible size. Firstly the climate will be irrevocably affected and I don't think the experts responsible for thinking up that idea know better than anyone else in that regard. Secondly, irrespective of where it's built, the tower would be vulnerable to all kinds of damage and may even introduce an extra wobble in the Earths motion, which is not going to be a good thing. It might even cause near-earth comets to form with hazardous results. Good grief, there's already more than nine thousand objects floating around up there being tracked, and seven hundred of them are significantly big. We really don't need another one.
 
Dec 2009
918
The Eiffel Tower is ~300m tall, and masses ~7000t. And, steel is ~7x more dense than graphene. So, assuming everything scales linearly (in all 3D), a ~300km tall ultra-tower (x1000) would mass ~1Tt (x1000^3). That would consume (more than) all of the known oil reserves of earth. So, even allowing for some architectural & engineering genius, ultra-towers could only be built up to (of order) hundreds of km high, a "stairway to the stratosphere" if not space. How much would getting a rocket-launch pad up above the whole atmosphere help, in reducing launch costs? How much cost comes from fighting through the thick atmosphere? Would being able to launch rockets, from a hundred km high, cut costs?

(Seemingly, the only plausible way of orbiting large payloads, would be with some sort of nuclear explosion based design, like nuclear "manhole-cover launching cannons", or Orion spacecraft.)

EDIT -- this source says an ultra-tower launch pad, hundreds of km high, could cut costs by ~10x. So, you'd save many millions of dollars per ton. If an ultra-tower cost trillions of dollars to build, then you'd have to launch millions of tons, before breaking even. Perhaps tourist tickets, for an actual "needle to space" ride (or some ultra roller coaster) could sell somewhat. But practically speaking, nuclear launch systems seem to monopolize the what-is-actually-possible "heavy launch" market.
 

caldrail

Ad Honorem
Feb 2012
5,357
Unfortunately you need to scale volumetrically. But that isn't the point. materials have strengths against various forces that remain annoyingly potent at larger scales. That's why larger animals are more bulky - they need to be, to support the weight. Whilst graphene might be impressively rigid at small scales, that rigidity is less on increasing scale as the bending and twisting moments are vastly greater, never mind the concatenation of material fractures on a crystalline scale.

Further, a linear tower stretchning something like a hundred miles straight up needs a means of reinforcing rigidity or face inevitable collapse. One means in this speculation is to increase the mass at the top of the tower and employ centripetal acceleration, although the mass would also act upon the base by gravity to some extent even with rotational compensation. That would however entail a minor movement of the Earths centre of gravity, no matter how successful the engineering, and thus instigate changes in climate with potentially far reaching consequences.
 
Dec 2009
918
natural earth-quakes can shift so much mass, like an ice-skater shifting their arms in or out, that the whole earth's spin speeds up, or slows down. And, tangentially relatedly, at present, humans move more mass around ("the earth moves with Palumbo"), than all natural erosive processes (wind, water, waves). So, humans are already affecting the earth's spin, at least a little.

Ultra-towers could conceivably be built, out of advanced carbon-based materials. However, ultra-towers hundreds of km high, or higher, would quickly consume all carbon on earth (coal, oil, biosphere = dead plants, dead animals, living plants & animals). Hypothetically, earth could be rendered into an inert Martian moonscape, with a single super-tall tower, protruding from (say) Africa.