From Royal Holloway, University of London
New research published today (Friday 27th June 2014) in the journal Nature Scientific Reports has provided a major new theory on the cause of the ice age that covered large parts of the Northern Hemisphere 2.6 million years ago.
The study, co-authored by Dr Thomas Stevens, from the Department of Geography at Royal Holloway, University of London, found a previously unknown mechanism by which the joining of North and South America changed the salinity of the Pacific Ocean and caused major ice sheet growth across the Northern Hemisphere.
The change in salinity encouraged sea ice to form which in turn created a change in wind patterns, leading to intensified monsoons. These provided moisture that caused an increase in snowfall and the growth of major ice sheets, some of which reached 3km thick.
The team of researchers analysed deposits of wind-blown dust called red clay that accumulated between six million and two and a half million years ago in north central China, adjacent to the Tibetan plateau, and used them to reconstruct changing monsoon precipitation and temperature.
“Until now, the cause of the Quaternary ice age had been a hotly debated topic”, said Dr Stevens. “Our findings suggest a significant link between ice sheet growth, the monsoon and the closing of the Panama Seaway, as North and South America drifted closer together. This provides us with a major new theory on the origins of the ice age, and ultimately our current climate system.”
Surprisingly, the researchers found there was a strengthening of the monsoon during global cooling, instead of the intense rainfall normally associated with warmer climates.
Dr Stevens added: “This led us to discover a previously unknown interaction between plate tectonic movements in the Americas and dramatic changes in global temperature. The intensified monsoons created a positive feedback cycle, promoting more global cooling, more sea ice and even stronger precipitation, culminating in the spread of huge glaciers across the Northern Hemisphere.”
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Myron Mesecke says:
June 27, 2014 at 9:48 am
Since North and South America are still joined (Panama canal could have little effect) why aren’t we still in an ice age if this was the cause for the one 2.6 million years ago?
We are in an interglacial Myron:
http://climate4you.com/GlobalTemperatures.htm#An%20overview%20to%20get%20things%20into%20perspective
I think the salinity part is interesting also in view of the global salinity reduction that must have resulted from:
https://en.wikipedia.org/wiki/Messinian_salinity_crisis
Talk about re-inventing the wheel!! This diminishes the excellent role that some geographers have and are making. Is Stevens a geographer? Many geography departments thee days are packed with geologists who cannot get jobs elsewhere.
From emsnews on June 27, 2014 at 4:14 pm:
Oh.
You’re one of them.
Why didn’t you provide your definitive evidence days ago? There are long pleasant discussions wrapping up now at another post where such evidence was explicitly requested. You could have changed the entire course of the investigation. As it was, no conclusive evidence of solar minimums causing cold periods on Earth was presented.
http://wattsupwiththat.com/2014/06/23/maunder-and-dalton-sunspot-minima/
There are still people keeping watch, you could take your strongest piece of evidence and present it for consideration.
Instead all we currently have is your unbacked claims here, a drop-off posting without substantiation.
Sadness.
I think the closure of the Panama Isthmus should have, technically, made ice ages less likely.
The closure diverted the equatorial current from flowing into the Pacific to flowing into the Gulf Stream (warming up the far northern Atlantic). And it also made the Atlantic more salty which provides for less sea ice development (perhaps half a degree equivalent).
The only way I see the closure of the Isthmus causing the ice ages is that it reduced the strength of the ocean flow into the Arctic from the Pacific side (less inflow at the Panama Isthmus, less outflow into the Arctic ocean from the Pacific ocean side). This would have then reduced the outflow from the Arctic ocean into the north Atlantic through the Fram strait.
ie. more ocean stays in the Arctic ocean for a longer period of time allowing more sea ice to build up and not just getting flushed out every year, resulting in sea ice in the summer, lowering Albedo etc.
A more likely explanation is that continental drift moved Greenland and Ellesmere Island just that little bit farther north, so that they became succeptible to the downturns of summer solar insolation in the Milankovitch Cycles. Before 2.7 million years ago, Greenland was too far south to build up large glaciers. Greenland is drifting northwest at 3.3 cms per year (1.9 cms to the north and 1.4 cms to the west) and has been doing so for about 55 million years since splitting away from the UK about where Iceland is today. That would mean it moved north by 990 kms in that timeperiod before freezing over 2.7 million years ago. Move Greenland 200 kms farther south and it would not have glaciers. Southeast Greenland GPS station VFDG.
http://sideshow.jpl.nasa.gov/post/links/VFDG.html
phlogiston says:
June 27, 2014 at 11:14 am
““Strengthening of monsoons during global cooling” – that’s curious, normally folks consider coolness to equal dryness.”
—————
The folks living in northern Europe during the Little Ice Age sure didn’t consider any such thing, to wit:
“During the LIA, there was a high frequency of storms. As the cooler air began to move southward, the polar jet stream strengthened and followed, which directed a higher number of storms into the region. At least four sea floods of the Dutch and German coasts in the thirteenth century were reported to have caused the loss of around 100,000 lives. Sea level was likely increased by the long-term ice melt during the MWP which compounded the flooding. Storms that caused greater than 100,000 deaths were also reported in 1421, 1446, and 1570. Additionally, large hailstorms that wiped out farmland and killed great numbers of livestock occurred over much of Europe due to the very cold air aloft during the warmer months. Due to severe erosion of coastline and high winds, great sand storms developed which destroyed farmlands and reshaped coastal land regions.” Source: http://www2.sunysuffolk.edu/mandias/lia/little_ice_age.html
thingadonta says:
June 27, 2014 at 6:37 pm
“Continental configuration, who’d a thought?
By the way, ever noticed that Africa, South America, North America, Australia are all upright N-S? Chances of this at random is very low. Only few places which aren’t upright are volcanic New Zealand, Japan, Central America, Indonesia etc.
Centrifugal force?”
There is no such thing. Centrifual force is an “apparent force” while the real force is called Centripetal force. Interesting thought though.
@jim G
I am not too sure what you mean by “upright” and thus, not being “upright” is also not really clear. As for volcanoes occurring in “upright” continents, I do believe that North America and South America have their fair share of volcanoes, and yet, you designate them as “upright.”
About ‘proof’ that the sun is the #1 driver of ice age/interglacial events is obvious. Way back 100 years ago Dr. Hubble and my father Dr. Meinel and my grandfather, Edison Petitt, all decided that the sun is responsible for the multiple ice ages once it was established that there was more than one ice age.
So they decided to study the sun much closer for this very reason. I don’t have to produce any online data to prove this, this information didn’t come to me via reading something, I grew up listening to them debate this very issue and know how they were thinking long ago because I lived with or near all of them!
The fact that there was an ice age in the first place was hotly (ahem) debated during much of the 19th century. My grandfather was born back then and grew up listening to this debate.
The shocker came at the turn of the 20th century that ice ages are periodic, not a one time accidental event. This SCARED EVERYONE and has oddly been eliminated as a fear in the last several decades for some weird reason.
There doesn’t have to be any ‘documentation’ for this information since I am the ‘documentation’ in the first place, i.e., first hand knowledge which I am passing on although people can ignore this and demand second or third hand documentation, I suppose.
I am waiting for some climate scientist to publish a paper on what the optimum climate is for our biosphere. The first question that would naturally flow would be where is our current trend in relation to this finding.
That nobody seems interested in this vital comparison indicates that the climate is being studied for other purposes. Since all the urgent demands that flow from today’s climate science all converge on policy solutions that involve statism, bigger government, higher taxes, less personal liberty, the bigger picture tells me all that I need to know about “climate science”. It is socialism and Gaia worship by other means.
I am also curious about how deep the ice got during the last several periods of glaciation of the northern hemisphere, but that is a question for another time.
The ocean level on the east side of the Panama Canal is a few inches higher than on the west side. This leads me to think that this is caused by the the easterly direction of the rotation of the earth. The water is ‘piling up’ on the east side. So … the flow would be east to west if Panama became an open waterway?
Anyone?
@buckwheaton
“I am also curious about how deep the ice got during the last several periods of glaciation of the northern hemisphere, but that is a question for another time.”
The Laurentide ice sheet on North America, at its height, about 30,000 years ago was from 2 to 3 miles thick at its thickest. It extended for 5 million square miles, covering all of Canada and the northern regions of the present United States.
Jim S
“I am not too sure what you mean by “upright” and thus, not being “upright” is also not really clear. As for volcanoes occurring in “upright” continents, I do believe that North America and South America have their fair share of volcanoes, and yet, you designate them as “upright.”
North and South America’s volcanos are on continental crust. The crust is aligned N-S.
I just noticed when drawing Australia at school is was hard to get it looking right (try it) and one way of doing it was to make sure the Cape of York was ‘upright’, or aligned N-S. The same goes for Chile-Argentina and South America. North America is also fairly aligned N-S, that’s partly why the Canadian Border is so straight, its easy to cut E-W across a N-S body. And so is Africa. And so is greenland. Then I noticed when drawing New Zealand it isn’t aligned N-S, and the reason-well its mostly volcanic. So is Japan. So is Hawaii. So is Indonesia. There must be something going on here. The chances of the majority of continents being aligned nearly N-S is nearly zero, yet they are. I’ve never heard anything about it though.
In the Proterozoic glaciations the continents were seemingly clustered around the south pole. In the Ordovician glaciation the continents were more dispersed but still almost completely in the southern hemisphere. It is clearly not necessary to cut off lateral ocean flow to chill out.
thingadonta says:
June 28, 2014 at 6:54 pm
“Then I noticed when drawing New Zealand it isn’t aligned N-S, and the reason-well its mostly volcanic. So is Japan. So is Hawaii. So is Indonesia. There must be something going on here. The chances of the majority of continents being aligned nearly N-S is nearly zero, yet they are. I’ve never heard anything about it though.”
—————-
thingadonta, there is something going on there and it is called …. tectonic plates, volcanoes and the “ring of fire” ……. and a picture is worth 1,000 words ….. so take a lookey-see at this picture graphic, to wit:
http://www.volcanogallery.com/_borders/RINGOFFIRE.gif
Tectonic plates are either moving away from one another or over/under one another and volcanic islands form on the boundary between two plates irrespective of their N-S or E-W alignment of said boundary. .
Wait a minute… a new theory? Are theories still allowed in climate science? I figured it would be settled by pronouncements from now on. This could get completely out of control, with people reverting to disprovable hypotheses, observations and archaic behaviors like that. How will our betters tell us what to do then?
Samuel C Cogar,
thingadonta, there is something going on there and it is called …. tectonic plates, volcanoes and the “ring of fire”
You mustn’t have read my earlier posts. What is strange is that most continents are aligned N-S (see above discussion, which I won’t repeat). The chances of this occurring at random is close to zero, as evidenced by the fact the volcanic arcs are not aligned N-S.
Centripetal force?
The currents that form the plate motions in the crust that originate in the mantle probably aren’t aligned or occurring at random, their actual positions may well be effected by the actual spin of the earth. It seems continent orientations in any case are effected by the spin of the earth.
“You mustn’t have read my earlier posts.”
————-
thingadonta, you asked a question, ……. I answered it.
Now I am not going to argue with you about “the odds are” ….. or “the chances of” …. anything happening or not happening in the natural world.
The FACT is, ….. whatever is, ….. IS. Explaining why …. IS, .. IS, …. is oftentimes controversial.
Here. thingadonta, , argue with this site, to wit:
http://www.astro.virginia.edu/class/oconnell/astr1210/guide12.html
Then skip down to this “heading” of …. E. “Plate Tectonics”
Milodonharlani:
The Oligocene was an ice age, beginning some 33.7 mya. The colder climate started abruptly at its beginning and ended at the next epoch- the Miocene, which was not an ice age but a period of warmth. This all is basic stuff, and the the temp. charts, given per dO18, are on the web.
As a geologist, I am up on this stuff. That the Isthmus of Panama causes the present Ice Age is unsupported speculation.