what are astronomical causes of ice ages?
98842
They are many theories on what causes ice ages, many of which are contraversial.  Some of the causes are astronomical in nature, others concern themselve only with earthbound events.\n\nHere are some of the astronomical factors thought to contribute to ice ages:\n\nSolar output\n\nThe sun's output varies slightly, in a 11 year cycle.  Longer cycles, with greater variation in output, probably contribute to ice ages.\n\nOrbital eccentricities\n\nThe earth's orbit has a 400,000 year cycle, where it moves from nearly circular to a more oval shape, and back.  A more oval shape makes for more radical seasonal climate change.\n\nAxial tilt\n\nThe earth's axis varies from 22.1 to 24.5 degree on a 40,000 year cycle.  The greater the axial tilt, the hotter the summers and the colder the winters.\n\nAxial orientation\n\nThe direction the earth's axis points varies according to a 25,800 year circle.  If the axial tilt points towards the sun during earth's closest approach, and away during its furthest approach, one hemisphere will have warmer summers and cooler winters than the other.  This is what the southern hemisphere currently experiences.\n\nOrbital inclination\n\nThe tilt of the earth's orbit around the sun increases and decreases in a 100,000 year cycle.  When highly tilted, there is less dust and debris between the earth and sun, resulting in more solar radiation reaching the earth.\n\nScientists are not sure which, if any, of these factors have the most influence on ice ages.
734739
Glaciers flow because of gravity.\n\nView this page:\nhttp://www.answers.com/topic/last-glacial-maximum\nFor info and a pic of what the world probably looked like during the last ice age. The grey denotes glaciers. The land (brown) has been adjusted for the drop in sea level and the ocean temperature difference is shown.\n\nThe ocean levels dropped. Much of the continental shelf which is now under water was exposed, dry land. The water that now covers them was locked up in the the glaciers.\n\nAlso look:\nhttp://uk.encarta.msn.com/encnet/RefPages/RefMedia.aspx?refid=461527006&artrefid=761570002&pn=3&sec=-1
138305
because they are to dumb to look back at history because it dosent exist. because think about it we are coming out of an ice age. it makes sense dosent it? fact: there have been ice ages. fact: there is a lot of ice in ice ages. so if you know about water then you know the same amount of it is here that was here when the earth began so literally it is dinasor piss. well during an ice age lots of stuff is covered in water/ice ( i know i live in minnesota and it is known that it was fully covered with ice.). so where is all the water? in ice bergs, glachiers, ect. so it would make sense that to leave an ice age most things would melt right? so they are still melting they will finish melting and cover parts of the world, then it will slowly freze causing an ice age. why would humans make that big of a difference? we are insignificant to the world.(everyone in the world could fit in texas and it would only be as densly populated as ny city). so our vehicles and combustable engines couldent have that big of an effect. but you say "what about the ozone thinning?" well i am not saying it hasent but it was because of the cfc's(cloral floral carbons) which broke up the ozone by atatching to ozone molocules. but the cfc's are no longer around. the ozone is healing itself as it is meant too. ther was no real hole only a thining which is also bad. but now it is closing up and returning to normal. if you think that the co2 we produced cant be good well think about it it isnt that mutch and while the earth was cooling after beieng created it released tons of co2. so what people will notice in the next 1-9000 years is it will warm up but in that time it will also cool down and eventually there will be an ice age. just because the great human race is here dosent mean that the earth will stop having ice ages as it has done by its self for billoins of years. think about it.
368747
yeah I heard all the crap about the new ice age what a crock same thing about human activity causing global warming bunch of nonsense read the astronomy reports the sun is burning a little hotter it does this ever so often like during the middle ages and think about it haven't we been coming out of an ice age for the past ten thousand or so years does this not mean it has been getting warmer
343314
Come to think of it, maybe yes in the long run....in the long run polar caps will melt moving huge chunks of ice which will cause earthquakes. Also, main cause of global warming is burning of fossil fuels which are obtained by mining and drilling up the earth, causing earthquakes.
175910
when a million years ago a meteor hit the earth and the dust that was created blocked the sun out and all of the dinosaours froze then came the ice age
443894
an ice age increases the coverage of ice on the planet which obviously makes it colder.. but also means that radiation from the sun is reflected back into the atmosphere making it cooler again and perpetuating the ice age. precipitation also decreases, ie it rains and snows less (antartica is the driest continent in the world). wind is produced by air currents which are created by warm air rising in various patterns around the globe, so wind patterns would alter which would also affect the climate. additionally ocean currents would be altered by the increase of ice and colder waters, which would again alter the climates in maritime areas
265470
ice age.\nThey are huge ice cubes left over from the Ice Age.  Mostly in the Northern areas, such as Alaska, they carve out beautiful Fjords, and are a wonder to see.
392244
This is complex theoram, and it happens to be taken from the exact idea of the previous ice age about 7000-10000 years ago in which only northern hemisphere froze over\nanother reason is dat the rate of pollution is higher in north then south (due to development) and effects of global warming shall be more drastic there.
787121
They could sink a lot.\nIt appears to be fact that in a heavy ice age there was no water between Siberia and Alaska, and that mankind (and many animals and plants) came thus to the American continent.\nAt the moment I wouldn't worry about a new ice age. We are doing everything to reach the contrary, a global warming. Sea levels are rising, endangering cities on the coast. Another effect of the global warming is, that strength and number of hurricanes rise.
1065195
Every 64 million years or so, the earth is hit by gigantic comet and the impact is so tremendous that vast amounts of dust and debris is sent into the atmosphere, blocking out the sun. This causes massive drops in temperature sending the earth into an ice age, wiping out all life on earth. This very same catastrophe wiped out the lifeforms on the planet before the dinosaurs existed, and the lifeforms before those, since this planet has not been hit once, but many times, making this an incredibly ancient planet. Don't know if 64 million years will have passed since the last ice age by 2026 though.
807687
The main reason is simply that the temperature is too high to maintain them. Glaciers melt in warmer climes. Even the glaciers of Antarctica, the Arctic and the world's greatest mountain peaks are melting in the current warming climate. \n\nThe glaciers of ice-age Britain had no chance when the global temperature rose at the end of that period.
125278
I don't think Ice Age will ever happen. That is in the past. I agree what profwmandrews says. But if it ever happens, the whole Earth will have no life. The black hole is getting stronger, and one day it may even suck up the Sun, and Earth will be dark and cold. If this is so, then you can call it the Ice Age.
375716
No one knows. Earth has gone through many climatic cycles. We could be headed for another ice age.
194769
The prevailing theory at this time is an asteroid impact that caused a nuclear winter. more than half the life on earth is thought to have become extinct at this time. I believe it was at the beginning of the cenazoic era. as evidence there is a layer of iridium at this geologic layer that covers the entire planet. Otherwise iridium is pretty rare on earth but quite common in asteroids.\n\nWhile this event may have contributed to the onset of an iceage, the energies involved were probably not great enough to give credit for an iceage.
1067115
no thats wrong. you want to look up the Milankovitch theroy of excentricity of orbits. he said it goes in 40,000 to 100,000 year shifts between 22.5 and 24 degrees.  If the previous answer is right we would have a global ice age every 6 months.  and it would be NOTHING like winter in the N.Hemisphere.  sea levels globallly would rise and fall by hundreds of meters every 6 months. basically we would be dead.
215895
Probably the age of ancient empires, though you should mention to your teacher that an archaeologist told you that none of those answers are very correct.