From the University of London
Scientists discover link between climate change and ocean currents over 6 million years
Scientists have discovered a relationship between climate change and ocean currents over the past six million years after analysing an area of the Atlantic near the Strait of Gibraltar, according to research published today (Friday, 13 June) in the journal Science.
An expedition of scientists, jointly led by Dr Javier Hernandez-Molina, from the Department of Earth Sciences at Royal Holloway, University of London, examined core samples from the seabed off the coast of Spain and Portugal which provided proof of shifts of climate change over millions of years.
The team also discovered new evidence of a deep-earth tectonic pulse in the region, as well as thick layers of sand within mountains of mud in a vast sheet, spreading out nearly 100km into the Atlantic from the Gibraltar gateway. The quantity of sand is far more than was expected and has been caused by the strength, speed and long duration of bottom currents flowing through the Strait of Gibraltar from the Mediterranean.
“The sediments we examined show various shifts of climate change over millions of years”, Dr Hernandez-Molina said. “In addition, our findings could herald a significant shift in future targets for oil and gas exploration in deep-water settings. The thickness, extent and properties of these sands make them an ideal target in places where they are buried deep enough to allow for the trapping of hydrocarbons. The sand is especially clean and well sorted and therefore very porous and permeable.”
The expedition, carrying an international team of 35 scientists from 14 countries, recovered 5km of core samples from an area along the Gulf of Cadiz and west of Portugal.
The research found that a powerful cascade of Mediterranean water spilling into the Atlantic was scouring the rocky seafloor, carving deep-sea channels and building up mountains of mud. This is due to Mediterranean water being saltier than the Atlantic and therefore denser, causing it to plunge downwards.
Dr Hernandez-Molina added: “We set out to understand how the Strait of Gibraltar acted first as a barrier and then a gateway over the past six million years. The fascinating results we came back with have hugely increased our understanding of the Mediterranean Outflow Water (MOW) that flows through the Gibraltar gateway and have led to some key discoveries about the relationship between climatic shifts, deep-water circulation and plate tectonic events over a huge timescale.”
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One modern, man-made, source of global warming might be the construction of the Assuan High Dam (1970), also with an impact on Mediterranean level and salinity.
See “Aswan High Dam (dam, Egypt) — Encyclopedia Britannica”, at http://www.britannica.com/EBchecked/topic/40203/Aswan-High-Dam
Almost all of the water that flows in behind the Aswan dam flows out of the Aswan dam – evaporation from the lake behind the dam – irrigation water that evaporated from the fields.
The rest? Water in (old) = water out (old) ~ water in (new) = water out (new) + losses.
The vast area of the Med allows so much more evaporation that the lighter (less salty) Atlantic water flows IN (see Willis above) through Gibraltar. At the same time, the heavier (saltier) deeper Med water in flowing out.
kadaka (KD Knoebel) says:
June 12, 2014 at 2:34 pm
Steven Mosher says:
June 12, 2014 at 1:50 pm
Gray.
http://typhoon.atmos.colostate.edu/Includes/Documents/Publications/gray2012.pdf
funny
And thus another Crypt-Mosh dropping is left in the comments, as he dares us to sniff it, feel it, taste it…
____________________
Not so hard to figure out, KD, Mosh is calling Professor Gray, stoopid.
Re Joseph Bastardi says: June 12, 2014 at 12:51 pm
Steve Oregon says: June 12, 2014 at 1:44 pm
Willis Eschenbach says: June 12, 2014 at 3:22 pm
RACookPE1978 says: June 12, 2014 at 4:48 pm
Hope I haven’t left anyone out. You’re all correct. Re “Elements of Physical Oceanography” by HJ McLellan, 1968 BeforeComputer, MOW forms an intermediate water mass that “. . .flows out over the sill of the Mediterranean and spreads out into the Atlantic at some 1500 m depth, being modified by mixing as it proceeds. Mediterranean water is characterized by salinity (36.5o/oo and temperature 12oC.”
This is thermohaline circulation, with warm saline water created by evaporation of Mediterranean surface water sinking and flowing out, being replaced by less dense (~35o/oo salinity) but colder surface water flowing in from the Atlantic. Suez water flow is miniscule.
The incoming density current plus tide provided the route for German submarines to silently traverse the Strait of Gibraltar. An interesting account is at:
http://formontana.net/uboats.html
[begin quote]
4. How fast are the currents through the strait?
The surface water in the strait consists of eastward flowing Atlantic water. At depth, there is dense, high-salinity westward flowing water. The water between these two layers is a mixing zone. Depending on the winds, the non-tidal water at the surface flows between 2 – 4 knots (2.3 – 4.6 mi/hr). The non -tidal currents below the surface flow to the west with speeds decreasing with depth.
The overall speed of the current can be affected by the tide as well. The tides in the region follow a semidiurnal pattern (two high tides and two low tides per 24 hrs). The strongest tidal currents occur midway between the high and low tides. The maximum current in the center of the strait can reach 5 knots and is typically stronger in the autumn and weaker in the winter. The strength and direction of the current, on and below the surface, is also slightly affected by the varying geography and depth along the coast.
5. How long would it take U-boats to pass through?
The length of the Strait of Gibraltar is approximately 25 – 30 miles long. Depending on where a U-boat commander decided to submerge, a passage of this length of time would take 5 hours or longer if relying only on the current to carry the boat. The most reasonable approach would have been to catch the tide when it was flowing the fastest and rig the U-boat for “silent running” to slightly increase speed without too much engine noise. Without good knowledge of the tides and currents a U-boat could easily lose a few precious knots in speed, which could make the difference between life or death. On the surface the U-boats could travel up to 17 knots and drastically cut down the amount of time they spent in the area.
I looked at seabed topography on Google Earth. There appears to be nothing unusual about the area. The continental shelf does extent further out from Gibraltar than from adjacent Spain or Morocco. Finding material in this outflow area seems completely expected.
Thanks Neil.
My only knowledge of currents at Gibralter comes from the movie Das Boot so I was surprised to learn of the Westerly flow. Always learning something at WUWT!
Gray:
“This is the biggest hoax I’ve ever heard in my life.”
NikFromNYC –
it could be a very expensive HOAX***
(3 pages) 16 June: Weekly Standard: Steven F. Hayward: Climate Cultists
Has the desperate global warming crusade reached its Waterloo?
The climate change crusaders, who have been at it for a quarter-century, appear to be going clinically mad…
While climate skeptics are denounced for mentioning “uncertainty,” the terms “uncertain” and “uncertainty” appear 173 times, while “error” and “errors” appear 192 times, in the 218-page chapter on climate models in the latest IPCC report released last September. As the IPCC admits, “there remain significant errors in the model simulation of clouds. It is very likely that these errors contribute significantly to the uncertainties in estimates of cloud feedbacks and consequently in the climate change projections.” The IPCC’s latest report rates the confidence of our understanding of clouds and aerosols as “low,” and allows that it is possible that clouds could cancel out most of the warming effect of greenhouse gases. If anything, our uncertainty about future climate change has increased with each new IPCC report…
The cruel irony for the climateers is that the more they hype the apocalypse of future climate change, the more farcically inadequate are their proposed remedies. Global primary energy demand is going to double over the next generation, and there is no one who thinks hydrocarbons—especially coal—aren’t going to play a large role in providing this energy, especially in developing nations…
***Absent an unusual level of political resolve from Congress, the climate campaign may yet succeed in hobbling the electric power sector in America. That would be a high price to pay for indulging a fanatical movement that in every other respect must be reckoned a pernicious failure.
http://www.weeklystandard.com/articles/climate-cultists_794401.html
Dr.Grey didn’t go along with then VP Gore’s campaign against the US over climate control so he suddenly found himself in the Clinton maul and ended up being awarded emeritus status.
Steven Mosher says:
Steven you are being paged.
http://wattsupwiththat.com/2014/06/12/the-temperature-forecasting-track-record-of-the-ipcc/#comment-1660952
From Alan Robertson on June 12, 2014 at 5:19 pm:
I meant Crypt-Mosh dropped off another reference, allegedly to a pdf in this case, that he cryptically won’t tell us what it is yet he expects us to examine it. Not so hard to figure out, A.
And if you click on links with a presentation like that, may you find all your M$ boxen enslaved to the botnets to their seventh past backup as just punishment for your transgressions.
Willis says:-
The Med is shallow.
No it is not it includes two subduction zones– so mini ocean trenches. It does have very high evapouration so its surface is actually lower than the Atlantic, hence the surface inflow at the Gib Straites. Water does flow out there as very dense bottom water which will carry sediment with it. The floor of the Med has many areas of evapourite, halite and gypsum/selenite, accumulating. The Suez Canal is concerned with surface waters only so no outflow there to the Red Sea which has similar evapouration rates and is again deep due to tectonics.
Reminds one of the Heinrich Event where debris from icebergs are dropped (after melting) onto the ocean floor which also indicate ocean currents. See paper here:
http://www.nature.com/nature/journal/v360/n6401/abs/360245a0.html
Perhaps they will check for iceberg material in their samples.
Curious George says:
June 12, 2014 at 1:56 pm
““examined samples from the seabed off the coast of Spain and Portugal which provided proof of shifts of climate change”. When examining corks from wine bottles from Spain and Portugal, I observed many sudden shifts of a horizontal plane.
What the hell is a shift of a climate change? A climate change?”
Perhaps the second derivative of climate change? d2/dct2 (humor?)
indeed Jim…. d “double-dot’ 😮
Steve Oregon says: June 12, 2014 at 1:44 pm
Steve,
In addition to the replies above and for a geological perspective Google the Messinian Salinity Crisis.
When the Mediterranean dried out in the late Miocene, the rivers of southern Europe and the Nile eroded down to form ancient canyons which are now buried below the site of their modern deltas. In the case of the Nile the canyon extended up stream as far south as Aswan. The footings for the Aswan High Dam were built into this buried canyon.
Merrick said @ur momisugly June 12, 2014 at 1:14 pm
There ya go – and I thought Jim Morrison was a Merkin. Butt then what would I know being a “commonwealthian”?
Phillip Mulholland.
The Med has never ”dried out”. due to plate tectonics it is a closing ocean, due to Africa moving north, formerly the Tethys Ocean.
Steve.
The Med stays more saline due to it being an enclosed basin with high evapouration. Evapouration exceeds inflow, through the Gib Straites,
johnmarshall says:
June 14, 2014 at 3:18 am
You say:
So the presence of the buried river canyon 2,400 m (7,900 ft) below Cairo can be ignored?
The Med did dry out. There’s a salt layer underneath sea floor sediments in the deep basin. There’s also a really thick salt layer in the Gulf of Suez, Miocene age I believe. I can’t recall if there’s also salt underneath the Red Sea sea floor. We also see a salt layer underneath Texas and Louisiana and the Gulf of Mexico. There’s salt in Nigeria, and all the way to Angola, and also offshore Brazil. And I saw a salt layer in Tanzania. They are all over. It looks like sometime seas dried out once in a while as continents moved around and closed access to the worldwide ocean.
Yes they’re on the right track. Weather comes from the atmosphere, climate from the ocean. Its where all the climate heat is and it circulates it on millennial timescales.
So … what did they find? When was it hotter and colder? Does it correspond with other palaeo data or, in the style of contemporary climate studies by the likes of Shakun, Marcott, Oreskes et al. does it totally ignore all previous research on the subject.
It looks like we only got the introduction – it would be nice to have the methods, results and discussion also.
One good thing about the short article however – no mention of CO2.