Last Ice Age
:confused:I'm deeply confused at what is perceived as 'received opinion' on this.:confused:
From what I have read, during the last ice age:
Now that, for me fails a basic sanity check. Water flows downhill in response to gravity, not usually uphill. With sufficient momentum, inertia will carry water uphill some distance, but not a lot. What "scientific" explanation is invoked that caused the contents of the seas to be puked uphill some 400 feet + the height of Ice on the Land?:scratch: Here, in Ireland (a dot on the map left of Britain) they credit this ice with hewing out valleys in NW Ireland on it's way to the sea. That too seems total BS, but the Irish have always had a love affair with distilled alcohol, which might explain it. The sea wasn't where the sea is now, and the ice didn't know where the sea was. Ireland's Continental shelf opens land bridges to Iceland, Greenland and takes in the Faroes, Britain, mainland France/Germany, Russia, Norway/Sweden/Denmark, etc. Water doesn't carve, It's a fluid that flows downhill - it's not a pneumatic drill! I can understand ice gouging down an incline, but not horizontally. And of course, there's no water for a long distance. |
How do mountains have snow caps?
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Did you intentionally avoid using the word "glacier"?
https://www.asf.alaska.edu/glacier-p...glaciers-move/ https://www.nationalgeographic.org/e...pedia/erosion/ |
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The USA greatly benefited from the last little ice age as it was a primary motivator for Europeans to relocate (emigrate/flee etc...) their countries for the vast wilderness of the new lands. Consider the opposite of your OP: https://www.smithsonianmag.com/smart...rees-12098835/ https://www.bbc.com/news/science-environment-19077439 |
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@ChuangTzu: I didn't mean to make a big thing of the drilling thing. Yes, water drills under pressure and glaciers move. Witness Greenland and West Antarctica at the moment. You would have to see the particular valleys I referred to in order to understand my point. The geography of the locality indicate that we lack the pressure to cause any of this to happen. And of course, all such indications stop at the sea shore. In what is now sea, we do have the incline and ice carving a valley under what is now below sea level doesn't seem an unreasonable proposition. Ireland is pretty flat. Mountains here are hills above 1,000 feet (305m). The highest is in the South @2,200feet (670m). With such a sea level, Ireland would be part of a Great European/Asian/African land mass, and there would be a land bridge from Russia to The North American Continent (Canada or Alaska) and continuing Eastward, you would get Greenland. I don't believe I expressed an opinion in my post, but asked what the received opinion was on the apparent physical impossibility of the sea level disparity. I should have focused my question better. I'm not an Ice age skeptic as such, but have my issues with physical impossibilities that appear to fail basic sanity checks. I will check up on your links, thanks. |
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The mechanism by which the sea water got uphill was gradual evaporation (which happens even in cold weather if you have a big enough surface) and then condensation into snow. |
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I'll think about that, and read some of the stuff I've been given to read. My first reaction is to agree that the seas had enough salt in them not to freeze. Has anyone else noticed that Antarctica is a desert because weather fronts don't intrude over it? Rainfall 6.5mm/year (or 0.256 in/year), or suchlike. Second reaction is to think that the Uniformist position must be in error for this to be the case. The uniformist position is that 'the atmosphere of the present is a guide to the atmosphere of the past.' So all dates over ~10k years BP are suspect. Third reaction (all poorly considered) is to wonder where the sun went? We would have this whole Europe/Asia/Africa land mass and another North America/Greenland chunk all covered in ice(with continental shelves exposed. What is invoked to change things so utterly? |
Basically.....
We have land & sea, we also have temperatures, temperatures cause some of the sea to evaporate, causing clouds, clouds amass this condensation, until to heavy to hold. Wind moves cloud formations around the world, (winds are caused by the Moon's pull on the Earth). If the cloud is blown over a certain height, what would have fallen as rain will fall as snow or hail, hail is ice, if it falls over the top of a hill, in enough quantity, it can form into glaciers. Glaciers are very big & heavy lumps of solid water, land under a glacier heats up a little, enough for it to move downhill, as it moves, the weight is enough to carve out valleys. As the glacier gets lower down it can & will return to water, owing to higher temperatures lower down on land masses. A large volume of water will erode soil & rock in its path to the sea, where it all starts over again. |
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Firstly, let's distinguish between the Ice Age and a glaciation. When the earth is in an ice age (and there have been several), the ice comes and goes. There are glaciations when it reaches the maximum extent, interglacials where it's at the minimum, and interstadials where there's been a slight improvement on the glaciation. What ended about ten thousand years ago was a glaciation, not the ice age. The ice age is still with us: that's why there's all that ice on Antarctica and Greenland.
What causes ice ages? Several factors are involved. Firstly, the position of the continents. Oceans keep heat better because the water circulates. When there's open water at a pole, it doesn't freeze. Currently the gaps between America and both Europe and Asia are too small for adequate circulation, so the polar sea gets colder. Land doesn't retain heat, so Antarctica never gets enough heat in the summer to counteract the cold in the winter. To get an ice age, you need two cold poles. Secondly, there's the fluctuation in heat received from the sun, mostly caused by cyclic variations in the earth's orbit. That triggers the variations within an ice age. Another factor is that a glaciation is self-reinforcing, since ice-sheets reflect sunlight. As for the original question, normally the sea water evaporates to produce clouds, the clouds give rain, and the rain flows back to the sea. In glacial conditions, the precipitation in frozen areas is snow and it doesn't melt, so it doesn't return to the sea. In the tropics, however, the sea water continues to evaporate. So, over a long period of time, a lot on the sea ends up as ice on land. This is "glaciation for dummies in five minutes" but I don't think I've over-simplified too much! |
David, very good post, cliff notes were fantastic. :)
Also, let's not forget the effect of solar "weather" which has a much larger impact on the Earths weather patterns/cycles then most realize or want to admit. https://phys.org/news/2019-07-solar-...l-effects.html And from: https://www.space.com/19280-solar-ac...h-climate.html Quote:
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Let's not forget atmospheric conditions. One factor for example is volcanic activity which places particulate matter high in the atmosphere over very large patches of the globe, reducing insolation which is massive enough to affect phenomena like El Nino. Another component having profound effect which has been carefully tracked, especially of late and going back almost a million years via records kept in ice cores, is CO2. This is also recorded via the fossil record over hundreds of millions of years and includes impacts as well as continental shift both laterally and vertically (mountain ranges come and go on those time scales).
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Well, Thanks to you all, I have now have some clearer understanding of the way people think about this. There is much for me to think on. I appreciate the differentiation between glaciation and ice age.
This ice age as I found it was definitely failing a sanity check but as we're talking 10k YBP, we can hardly expect to have weather reports of wayback archives to scour for information. Thanks for the links and information. To go by this, however, the world seems to have been stuck between desert and glacier. It's a wonder that people or animals lived. We had a situation a few years back here in Ireland where flying was banned and holidays to the 'Costa Plenty' were cancelled because some volcano in Iceland blew off dust etc. came in a cloud going South but it would take a lot more than that to make a serious dent in sunlight, and the cloud never went to, or didn't stay in the upper atmosphere. I'm definitely skeptical on that, and leery generally on historical sciences generally. I can't get past the last 5 lines of the Microbe, by Hilaire Belloc: http://poetry-archive.com/b/the_microbe.html EDIT: No way to mark this thread solved, but it is. I'll have top let it rumble on. |
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As for "The Microbe" I really don't understand why Mr. Belloc didn't just look through a microscope to see for himself. Almost 200 years earlier Anton van Leeuwenhoek was able to see one-celled lifeforms with self-made microscopes employing a drop of water for a lens. Excuse the pun but I find that "Hilair-ious. Skepticism is an important attribute but it needs to be balanced by critical thinking and the understanding that our unaided five senses can only tell us just so much about the world. It wasn't that long ago that even the wildest science fiction could barely imagine home computers let alone the internet or the Higgs Boson. It isn't wise to let skepticism become a passive default response that stops with "I only trust what I can see with my eyes". Surely you don't imagine the Sun travels around the Earth? EDIT: No way to mark this thread solved, but it is. I'll have top let it rumble on.[/QUOTE] |
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Also check out the 1883 Krakatoa eruption which apparently dropped temperatures in the Northern hemisphere by 1.5 degrees with ash staying in the atmosphere for months. Play Bonny! :hattip: |
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/unsubscribes
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That point is that when changes occur, they "leave footprints" and we, or at least some humans, can "read" those changes left over from billions of years ago. It is by no means complete or perfect but it is all we have or can have and it improves over time. We know a decent amount about how The Cosmos works but we know a great deal about how things work down here on Planet Earth. To simply stand with arms folded defiantly across one's chest and challenge "Show me! I need to see it and touch it or it isn't real" relegates one to a life of the (supposed) Concrete having no concern or understanding of the Abstract, even those as fundamental as "A is A" or "1 + 1 = 2". If our 5 senses were a perfect judge without abstract, critical thought, there never would have been a profession of Magician. Climate isn't Magic. It does have patterns that we can see, track, and understand. |
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Apparently I can't unsubscribe. I started this, remember? :(
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Don't have it here, bit I started this thread.
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