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Post by principled on Jun 16, 2011 16:40:00 GMT 1
Nicck rr So what is your position? Do you believe that CO2 rises because changes in solar output raises temperature which causes CO2 to be released from natural sinks, thus "magnifying" the temp. change or do you think that CO2 rises (pre industrial) for some natural reason and that this in turn causes warming whether or not solar activity activity has increased? P
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Post by speakertoanimals on Jun 16, 2011 19:04:18 GMT 1
No need for an OR there. The CO2 doesn't care where it came from. With everything else being equal, more CO2 means greater greenhouse effect, hence greater equilibrium temperature. If system already reached that temperature, CO2 can then maintain it (or slow the cooling), when the driver that initiated that higher temperature is removed. Which explains the relation between the curves for solar forcing and that glacial/interglacial temperature curves.
If CO2 is added to the system when the system is a lower temperature than that which the amount of CO2 would give as the equilibrium temperature, then the sun will cause temperature to rise, as system tries to attain that new equilibrium temperature.
Which is a grossly simplifed (but not as simple as yours!) scenario.
Perhaps some on here are mystified by my use of 'equilibrium temperature'? It's not necessarily an actual temperature of the system, just the temperature that the system is trying to reach. Until it's there, you can have a net cooling or net warming depending on which direction you're approaching it from.
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Post by nickrr on Jun 16, 2011 20:03:26 GMT 1
The whole point is that CO2 levels rise for all sorts of reasons. For ice ages this is initiated by orbital changes etc (as discussed above). In recent decades the evidence is clear that it's been principally burning fossil fuels.
To argue that because it happened in one way in the past it always has to happen that way is nonsensical.
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Post by StuartG on Jun 21, 2011 9:04:01 GMT 1
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Post by marchesarosa on Jun 25, 2011 14:52:41 GMT 1
Megaplumes and Volcanic Gasses 24 June 2011 by E.M.Smith Well, a bit more “Settle Science”… Seems we’ve figured out that we really don’t know what is happening on the ocean floor in terms of volcanic venting of massive amounts of heat and gasses after all… From: news.nationalgeographic.com/news/2005/12/1212_051212_megaplume.htmlHydrothermal “Megaplume” Found in Indian OceanBrian Handwerk for National Geographic News December 12, 2005 Yes, that’s 2005, but I still like the article… An enormous hydrothermal “megaplume” found in the Indian Ocean serves as a dramatic reminder that underwater volcanoes likely play an important role in shaping Earth’s ocean systems, scientists report. The plume, which stretches some 43.5 miles (70 kilometers) long, appears to be active on a previously unseen scale. “In a nutshell, this thing is at least 10 times—or possibly 20 times—bigger than anything of its kind that’s been seen before,” said Bramley Murton of the British National Oceanography Centre. Scientists reported the finding last week at the fall meeting of the American Geophysical Union (AGU) in San Francisco. Researchers also announced newly discovered deep-sea hydrothermal fields in the Arctic Ocean and the south Atlantic. The appearance [discovery, rather] of hydrothermal vents around the world suggests that they are a far more common part of the ocean system than once believed and could be a major influence on circulation patterns and ocean chemistry... “I’d be surprised if in the next five years we didn’t experience a mini-revolution in terms of finding these [fields] in places where they are not supposed to exist,” said geophysicist Robert Reves-Sohn of the Woods Hole Oceanographic Institution. Volcanic Bombshell Hydrothermal vents are volcanic hotspots that emit gasses and mineral-enriched water as hot as 760°F (400°C). The heat from these vents supports unique ecosystems where creatures survive using thermal and chemical energy in place of sunlight. Megaplumes like the one found in the Indian Ocean are probably caused by undersea volcanic eruptions, though scientists aren’t yet certain. “Once formed they can possibly hang around for years,” Murton said. The heat from such events could have a dramatic effect on ocean circulation, which plays a role in determining Earth’s climate. “The energy content is an order of magnitude greater [than ordinary plumes], and the thermal power may be many orders of magnitude greater,” Murton said. “A normal hydrothermal vent might produce something like 500 megawatts, while this is producing 100,000 megawatts. It’s like an atom bomb down there.” Recent studies have attempted to factor the heat from the world’s known hydrothermal ridges into ocean circulation models. “Some studies estimate that for the Pacific, background thermal heating might increase ocean circulation by up to 50 percent,” Murton said. Regular hydrothermal fields stir the water for only a few hundred meters (about a thousand feet) above the ocean floor. “But these megaplumes can reach a column of 1,000 to 1,500 meters [3,280 to 4,920 feet], so it reaches right up into the midwater,” he said. But even the Indian Ocean megaplume may be small compared to larger underwater eruptions that have as yet gone undetected.... The new data on hydrothermal fields and megaplumes underscores the fact that volcanic activity on the ocean floor remains a largely mysterious phenomenon.
“Ninety percent of the Earth’s volcanic activity takes place underwater,” Murton said. “Just because we can’t see it doesn’t mean it’s not there.”So we know we are substantially clueless about 90% of the global volcanic activity, that it has a massive energy and CO2 output, and that it varies in ways we do not ken. It stirs the ocean from great depth to much higher levels than we ever thought, and “is like an atom bomb” in terms of energy; but can run for years… Yeah, so much for “settled science”… Courtesy of Chiefio here chiefio.wordpress.com/2011/06/24/megaplumes-and-volcanic-gasses/
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Post by speakertoanimals on Jun 27, 2011 13:57:54 GMT 1
Isotopic analysis my dear, you just keep recycling OLD papers, and hoping that the questions you repeatedly fail to answer will just stay hidden under the dross.
WHY do you think people on these boards are too stupid to follow a link? Most of us know how to open more than one tab, you know......................
Anyway, looks as if what is interesting about megaplumes is that volcanic activity at mid-ocean ridges is sporadic:
what seems to be the case is that when a vent forms, can get this intial huge belch, which gives rise to a large and relatively long-lived swirl of hot hydrothermal fluid in the oceans. It's not, as far as I can see, NEW volcanism, just a sporadic (and interesting), big belch.
We all knew the transfer of heat from earths interior to the exterior was very patchy anyway.
I should just add, the SIZE figures for the megaplume refer to the water circulation, not the site that produced it.
It sounds pretty exciting, but five years down the line since the Indian Ocean event.........................
The significance of these megaplumes? I have to stress they are TRANSIENT events. Article by Murton (quoted in Indian Ocean stuff):
So, main interest here is that having a BIG swirling lump of water may distribute larvae, and help explain why distance new ventb systems get colonized in the way they do.
So, big, transient, showy, and interesting, but not for the reasons that the volcano-warmers claim......................
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Post by speakertoanimals on Jun 27, 2011 16:06:03 GMT 1
This seems to be creating confusion. The megaplume, from all the references I can find, is a transient belch. Okay, a BIG belch, with overall a lot of thermal energy. but its not as if there is a continuous atom bomb going off (and the atom bomb comparison is a bit of hyperbole anyway). Persists for years -- it's not clear if they meant the circulation pattern caused by an individual bolus of hydrothermal fluid, or the potential to generate further belchs. The point is that rather than being a slow, continuous venting (as in black smokers), there seem to be these occassional BIG belchs -- the point being they generate a DIFFERENT sort of water circulation to the slow, continuous stuff. That is why oceanographers are interested, the stirring effect. Persists for years -- finally tyracked some stuff down, it is the Carlsberg ridge that is the thing. Seems that the megaplume is a transient event, that releases maybe 10^17 joules for CR2003, butu a year later, they can still measure chemical anomalies in the water column, but thermal and optical signals reduced with time. THAT seems to be the 'persists for years' line. Hence rather than 'an atom bomb' going off for years, we have a transient, extremely large event compared with what people expected on these slow-spreading ridges, but a short-term belch, although the 'smell', if you like, persists for quite a while. www.ias.ac.in/currsci/aug102008/355.pdfbut it's NOT volcanic activity where we never expected it, it IS on a mid-ocean ridge after all, seems people just didn't expect such large events on what were thought of as slow-spreading ridges. and finally I found the CR2005 event by Murton: eprints.soton.ac.uk/40706/So, looks like rather than slow leak, occassional big belches, but NOT the great unseen undersea volcanism sufficient to heat the seas that the volcanic-warming crowd seem to think.................... In terms of CO2, same applies as for rift activity and spreading in general -- the NEW oceanic crust being created, that is the root cause of all this activity, is a SINK for CO2....................
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Post by StuartG on Jun 27, 2011 22:57:10 GMT 1
"In terms of CO2, same applies as for rift activity and spreading in general -- the NEW oceanic crust being created, that is the root cause of all this activity, is a SINK for CO2...................." As I understand it, some CO2 is taken into the lava, but most is 'free' and either combines to form carbonic acid or just gases off. "Low oxygen and pH levels are important factors in supporting the high amounts of Fe (iron), one of the hallmark features of Lōʻihi. These characteristics make a perfect environment for iron-oxidizing bacteria, called FeOB, to thrive in." The vent fluids are characterized by a high concentration of CO2 (up to 17 mM) and Fe (Iron), but low in sulfide. %CA%BBihi_Seamount#Hydrothermal_vent_geochemistry" rel="nofollow" target="_blank">en.wikipedia.org/wiki/L%C5%%CA%BBihi_Seamount#Hydrothermal_vent_geochemistry
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Post by speakertoanimals on Jun 28, 2011 13:27:06 GMT 1
The entire process of what happens to carbon from the mantle at mid-ocean ridges is complicated, but I found this nice comment which summarizes what I thought was the situation:
MORB: mid-ocean ridge basalt.
Some of that carbon DOES get out, but by a long route (I think), subduction zones then subaerial volcanism.
As with megaplumes, I think some people are thinking about submarine volcanism as if it were just ordinary volcanoes, but under the sea, whereas the volcanism at mid-ocean ridges (whcih after all IS the major volcanic/tectonic activity going on!) is rather different.
Also:
It is easy to understand how SOME people can be convinced by the 'hidden submarine volcanoes' argument. What do volcanoes do on land? Pump out loads of dust and ash and gases. Hence what would volcanoes underwater do? Find some link which says that majority of planets volcanic activity occurs underwater, plus some newly discovered big feature (like megaplume of some snazzy underwater volcanism), and hey presto, you have created a plausible-sounding look where all the CO2/heat came from argument.
Riposte:
1) Isotopic composition of CO2 not correct (if you believe CO2 is increasing in the first place).
2) Heating the sea from underneath isn't what we see, instead we see heating of the surface waters.
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Post by principled on Jun 28, 2011 17:58:39 GMT 1
STA: One thing that came to mind whilst reading your post was that what effect does the absorption of CO2 by the deep ocean via these mega-plumes etc. impact on the ocean's ability to absorb CO2 from the atmosphere? IE: Rather than considering the scenario of (incorrect Isotopic) CO2 eventually being released form the ocean to the atmosphere and so adding to "atmospheric CO2", is it not possible to turn the argument on its head and consider whether the absorption of CO2 by the deep ocean affects the uptake of CO2 from the atmosphere? The net result in each case would be a rise in atmospheric CO2, but in the second case there would be no isotopic difference in the CO2. Just a thought P
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Post by speakertoanimals on Jun 28, 2011 18:31:34 GMT 1
I don't know if there IS any net increase of carbon in the deep ocean -- WHERE do you think the cooling crust gets the carbon it 'sinks' if not from the sea-water?
As far as I can see, what they are most interested in with megaplumes is the HEAT (only about 0.25 degrees C difference compared to 'ordinary' seawater, but its the total heat content that amazes), and the transport of minerals and larvae for vent lifeforms.
But then I was just interested un debunking the undersea volcanism stuff, not the whole carbon cycle in the oceans............................
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Post by StuartG on Jun 28, 2011 20:45:30 GMT 1
'Smokers etc' Here's some of the 'finds' made on the 'net. The term 'Hydrothermal vent' seems to cover at least three types, and the Wiki seems to give the best account to start with... en.wikipedia.org/wiki/Hydrothermal_vent#Physical_properties and this extract is the most interesting, "In contrast to the approximately 2 °C ambient water temperature at these depths, water emerges from these vents at temperatures ranging from 60 °C up to as high as 464 °C.[2][3] Due to the high hydrostatic pressure at these depths, water may exist in either its liquid form or as a supercritical fluid at such temperatures. At a pressure of 218 atmospheres, the critical point of water is 375 °C. At a depth of 3,000 meters, the hydrostatic pressure of sea water is more than 300 atmospheres (as salt water is denser than fresh water). At this depth and pressure, seawater becomes supercritical at a temperature of 407 °C (see image). However the increase in salinity at this depth pushes the water closer to its critical point. Thus, water emerging from the hottest parts of some hydrothermal vents can be a supercritical fluid, possessing physical properties between those of a gas and those of a liquid.[2][3] Besides being superheated, the water is also extremely acidic, often having a pH value as low as 2.8 — approximately that of vinegar." so 'things aren't behaving like they do on the surface'. two main divisions of hydrothermal vents are black and white smokers. Black smokers seem like the 'dark satanic mills' of the undersea world, belching all sorts of minerals. gases, bits of lava and, including our new word, supercritical fluids. The white smokers are more 'gentle' [relatively speaking!] than the black ones, "White smokers are vents that emit lighter-hued minerals, such as those containing barium, calcium, and silicon. These vents also tend to have lower temperature plumes. These alkaline hydrothermal vents" So there is a 'characterisation' [US word] of these by difference, in that 'White are alkaline' and Black, "black smokers typically emit particles with high levels of sulfur-bearing minerals, or sulfides" are 'Acidic'. Of further interest on this Wiki page is the picture of a White smoker [top right] with the attached legend "White smokers emitting liquid carbon dioxide at the Champagne vent, Northwest Eifuku volcano, Marianas Trench Marine National Monument" , so a Carbon Dioxide superfluid, new word and concept. en.wikipedia.org/wiki/Hydrothermal_vent#Black_smokers_and_white_smokersStuartG
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Post by StuartG on Jun 28, 2011 21:04:42 GMT 1
From National Geographic, news.nationalgeographic.com/news/2005/12/1212_051212_megaplume.html"Hydrothermal vents are volcanic hotspots that emit gasses and mineral-enriched water as hot as 760°F (400°C). The heat from these vents supports unique ecosystems where creatures survive using thermal and chemical energy in place of sunlight. [that refers to the 'normal' ones as mentioned above... Megaplumes like the one found in the Indian Ocean are probably caused by undersea volcanic eruptions, though scientists aren't yet certain. "Once formed they can possibly hang around for years," Murton said. The heat from such events could have a dramatic effect on ocean circulation, which plays a role in determining Earth's climate. "The energy content is an order of magnitude greater [than ordinary plumes], and the thermal power may be many orders of magnitude greater," Murton said. " ""A normal hydrothermal vent might produce something like 500 megawatts, while this is producing 100,000 megawatts. It's like an atom bomb down there." " ""Some studies estimate that for the Pacific, background thermal heating might increase ocean circulation by up to 50 percent," Murton said. " ""Ninety percent of the Earth's volcanic activity takes place underwater," Murton said. "Just because we can't see it doesn't mean it's not there." " StuartG One criticism of this article is that they appear to use 'plume' and 'hydrothermal vent' interchangeably. They don't know at present what generates the 'megaplume', possibly a seamount.
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Post by marchesarosa on Jun 28, 2011 21:43:07 GMT 1
How refreshingly different Murton's opinions are from the usual "negligible effect" fob off I have received when I have raised the effect of undersea vulcanism before from those who claim the atmosphere rules the planet's heat and CO2 budget.
As for the other quotes you have provided, STA, I see they peppered with phrases indicating high levels of uncertainty and lack of knowledge like "apparently triggered", "observed only rarely". "significance remains uncertain", "inferred", "the question remains", "thought to cause", "may be more significant and effective than hitherto imagined".
This is my problem, STA. About this almost totally unexplored realm people like YOU (not Murton) are recklessly promoting the idea that we have ENOUGH knowledge to suffice for unconditional acceptance of the catastrophic CO2 induced global warming scenario and for placing all our eggs in the CO2 basket.
Sorry, no, I don't think so and NOTHING you claim that is "known" about the ocean depths will convince me otherwise.
And your pal's "Thing is, all of this CO2 ends up disolved in seawater, or precipitated in hydrothermal alteration, so it has no direct short term impact on the atmosphere." is just far too neat - all this emitted CO2 immediately absorbed into sinks in the very place it is produced? I don't think so, but it is highly convenient for alarmists to claim this.
And I have heard no-one is denying that the sun heats the surface waters, STA. It's the sources of deep sea heat that are under discussion on this thread.
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Post by nickrr on Jun 29, 2011 7:46:08 GMT 1
You started this thread and your first post was entirely focused on CO2, nothing about heat. You can't even report your own posts correctly!
Unlike AGW deniers, science doesn't deal in certainty.
Your usual distortion of the arguments. Of course the CO2 isn't immediately absorbed in the same place. There is a cycle of carbon in the deep oceans. It's just that the evidence shows that the net result of this cycle almost certainly doesn't release extra carbon into the atmosphere.
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