Volcanos in Gakkel Ridge NOT responsible melting the Arctic ice
July 10, 2008I am not only a global warming skeptic, but a skeptic in general. I call ’em as I see ’em.
There have been some attempts to link the arctic sea ice loss of the last several years to reports of volcanoes under thousands of feet of water in the Gakkel Ridge,
The truth is that all the energy from a volcano the size of Mount St. Helens could only melt 100 square kilometers of three meter thick ice. This is a trivial amount of ice for the arctic region, which typically oscillates between about 4 million and 14 million square kilometers every year. 100 square kilometers is only one hundred thousandth of the yearly change in Arctic sea ice extent
.
Arctic region showing the location of the Gekkal ridge. This Google Earthimage, with annotation by Moriarty, obviously does not show the arctic sea ice.
Let’s do some simple math to work this out:
First, how much energy is released by a volcano? Of course, if varies greatly, but we just need an order of magnitude approximation for now. A common estimate for the energy released by the Mount St. Helens explosion is 24 megatons, where a megaton is supposed to be equivalent to the energy released by a million tons of TNT. A joule is the basic SI unit for energy, and one megaton is equal to 4.2 million billion joules (4.2e+15 joules). Therefore the 24 megatons released by Mount St. Helens translates into about 100 million billion joules (1.0E+17 joules). That is:
(4.2E+15 joules/megaton X 24 megatons = 1.0E+17 joules).
So now the question is: how much ice could be melted by 100 million billion joules of energy? It takes about 4 joules to heat one gram of water by 1 degree C. But it takes many more joules to melt a gram of ice. The amount of energy needed to melt a gram of a solid to a liquid is called the “heat of fusion.” The heat of fusion for water is 334 joules per gram. If we divide the total energy of the volcano by the heat off fusion of water, we will get the number of grams of ice that could be melted. Doing the math:
1.0E+17 joules / 334 joules per gram = 3.0E+14 grams
OK, the energy released by Mount St. Helens would melt about 3.0E+14 (three hundred million million) grams of ice. A gram of ice is about 1.1 cubic centimeters (1.1 cc), so we can round it to 1 cc just to make things simple. That means that Mount St Helens released enough energy to melt 3.0E+14 cubic centimeters of ice.
Let’s get a handle on what “3.0E+14 cubic centimeters of ice” means. A cubic meter of ice is the same as 1,000,000 cubic centimeters of ice. So, 3.0E+14 cubic centimeters of ice are the same as 3.0E+8 cubic meters of ice. Still a pretty big number to grasp. A sheet of ice that is one meter thick and one square kilometer would have a volume of 1 million cubic meters (1.0E+6 m3). In this case, 3.0E+8 cubic meters of ice would be the same as 300 square kilometers of ice that is 1 meter thick.
Now we have a number that is easier to deal with. That is, the energy of Mount St. Helens would be enough to melt 300 square kilometers or ice that is 1 meter thick. Finally, we’ll make the estimate that the ice is about 3 meters thick in the arctic. (Of course, it is much thicker some places and much thinner in others.) Then the energy of Mount St. Helens would melt about 100 square kilometers of ice in the Arctic.
The bottom line
The Arctic goes through some serious changes in sea ice extent every year as the season change. The sea ice extent changes by about 10 million square kilometers every year. 100 square kilometers is about one hundred thousandth of that. It would take a thousand volcanos the size of Mount St. Helens every year to account for just 1% of the yearly Arctic ice loss.
I am not only a global warming sceptic, but a skeptic in general. I call ’em as I see ’em.
Mount St Helens explosion, May 18th, 1980.
Climate Sanity 
I think it would translate to less than that in reality since the volcano is on the bottom of the Arctic sea and there is a considerable amount of water that would have to be heated before the ice would be affected.
Unless the volcanism is at or near the surface (as it is along the coast of the Antarctic) I would not think it would have much of an effect.
Lucky warm water doesn’t rise … oh wait it does!
Bill Marsh,
Thanks for your comment. You are absolutely correct. I am assuming all the energy is transferred through the water, without heating it, etc., directly to the ice.
My point is that the upper limit of the amount of melted ice is vanishingly small.
Tom
ClimateSanity
My mathematical knowledge consistsa of the multiplication tables I learned in 1932
Given how much we don’t know about this volcanism which wasn’t discovered till long after it occurred, I’d say there is no real evidence to disprove any such contention at this point. Let’s hear more about this before making a slam dunk comment on such huge processes.
David Gladstone,
Like I said, I call them as I see them.
The numbers pretty much say it all. This one is, in fact, a slam dunk.
Tom
So, what about the effect of the warming over time? There are quite a few volcanos under the water in the Arctic and they have been heating the water up there for years.
I like seeing the calculation and it its very interesting reading. Thanks. I just had a couple of thought reading this though.
When I first read about the volcano eruption under the arctic ocean, I heard that up until this was discovered it had been thought impossible for an eruption at that depth because of the intense water pressure above it. So wouldn’t that mean that this eruption would be large compared to Mt. St. Helens? As also indicated by the fact that this would have “created explosive fountains rising up to 2 km in the water column.” I think your energy cacluation might be off by an order of magnitude low. Even still by your figures that would be only 1000 sq kilometers. Maybe I’m guessing too high?
“The volcanic events at Gakkel Ridge were not a one-off, the team says, and could be ongoing.” So an ongoing effect could change your calculation too. What do you think?
My quotes come from: http://environment.newscientist.com/article/dn14203-arctic-volcanoes-exploded-at-impossible-depth.html
But the ongoing effect would have been likely occurring for hundreds or thousands of years. As such, it would not change the energy balance of the region at all, as it would already be factored in, so to speak.
In other words, regular volcanic eruptions do not explain changes in temperature. There would have needed to have been a recent massive change in eruption patterns. How massive a change? The mathematics provided above tell us.
Yes. The circulation cycles would carry steady heat out and back into Atlantic currents, maintaining an equilibrium. The observation question really is related to unusual, single eruptions. I wonder if you would entertain the math of a large magma rise under Iceland pre-dating the 2010 eruption?
Lloyd,
Thank you for the comment.
You are correct that we do not really know the energy released by this volcano, and it could indeed be an order of magnitude greater than Mount Saint Helens. Maybe two orders or magnitude greater.
But even if it were two orders of magnitude greater, it would still take 10 such eruptions a year to melt just 1% of the ice that normally melts during the expected seasonal oscillation.
And the chances of this happening year in and year out – very remote.
Tom
David G., even if the volcanic activity was ongoing, it’s not at a steady state. From what I’ve read, ’99 and ’01 had very large seismic activity in that area indicating very large volcanic activity.
What about the fact the ice is in contact with salty sea water? How would that play into your calculations?
Thanks.
I read there were 12 volcanoes discovered plus who knows how many thousands of under sea vents “black smokers”in the Arctic,Also an estimated 3 million vents world wide which would have an effect on water finding it’s way into the Arctic Sea.I think there’s a real possibility you may have underestimated the effect.Also there are satalite pics that clearly show the melt above the Gekkal ridge area.Don’t forget when boiling hot water or steam is released from high pressures it creates super heated steam.
The fact there were unusual polar axis wobbles that would create plate boundary stresses in the same time frame of BOTH 1930’s high temps AND AROUND 2000 high temps that makes a higher rate of geothermal activity therefore higher Ocean temps much more believable.
Besides the earth-quakes that go along with plate movement would be the reason for ice shelves to break and speeding up of some glaciers rather than an effect of melting.The fact that the Ice had sharp cracks showed no rounded edges from melting proves the point even further.
Lewis,
The numbers I calculated for the amount of ice that could be melted by a Mt. St. Helens size volcano are an upper limit. That is, if all the released energy were transported to the ice, without any losses along the way. In reality, the considerable amount of water between the volcano on the bottom of the ocean and the ice on the top would also have to be heated, reducing the amount of energy to reach the ice.
Consequently, the actual melting would have to be less than what I calculated. Hence, itis an upper limit.
Best regards,
Tom
Barry Day,
You make some interesting points, but I am unconvinced. Here’s why:
The volume of the oceans is about 1.3 billion cubic kilometers (1.3E+9 km3). There are 1,000,000,000,000,000 cubic centimeters (1E+15 cm3) in a cubic kilometer. So, there are about 1.3E+24 cm3 of water in the ocean.
It takes about 4 Joules of energy to raise one cubic centimeter of water 1 degree C. So it would take about 5E+24 joules of energy to raise the oceans 1 degree C.
Recall from the post above that Mt. St. Helens released about 1.0E+17 joules of energy.
So it would take the energy of about 2E+7, or 20 million, Mt. St. Helens sized eruptions to raise the temperature of the oceans 1 degree C.
Keep in mind that I am talking in terms of energy, and my calculations represent an upper limit. There really doesn’t appear to be anyway to get around it.
Black smokers, for example, are tiny pinpricks compared to a full scale eruption like Mt. St. Helens. They are found along deep ocean ridges. It would take billions and billions of them to have much effect.
Best Regards,
Tom
“It takes about 4 Joules of energy to raise one cubic centimeter of water 1 degree C. So it would take about 5E+24 joules of energy to raise the oceans 1 degree C.”
Is that the surface top centimeter only?as heat rises and spreads.
At least the Volcanoes and vents should be mentioned as a posibillity as a reason when ice shelves with no evidence of melting(sharp corner edges) break away.
As for not having much effect!
Circles in Thin Ice, Lake Baikal, Russia
http://eol.jsc.nasa.gov/sseop/EFS/photoinfo.pl?PHOTO=ISS019-E-10556
Thanks for answering Tom,
This is where I’m having problems understanding how the Ocean does warm up at all if that were the caseas,The same rules would apply for the rather weak effect of the Sun in that region.Thats why I think the under-sea Volcanoes,vents etc,and what has not been mentioned yet;
(1)”Who knows how many Sq Klm’s of warm Sea floor crust area heat transfer”?
(2The interaction between Sun,Earth Magnetic Fields.
“The fact that the core-mantle interface is a super-conducting region…….The “hot spot” generates a thermal power of up to 10 13 watts and an equatorial current of about 10 9 amperes. The current is held to a narrow equatorial path by the well-known “pinch effect”. The total resistance of the equatorial circuit is no greater than 10 -10 ohms. The 10 9 ampere current creates the “polar” magnetic field. The secondary “non-polar” fields are induction effects due to minor fluctuations (ripples) in the equatorial current.
Paleomagnetic polarity reversals are initiated by turbulence, and by imbalances in kinetic pressure (nkT) and magnetic pressure (B 2 /2μ0). Westward drift is explained by the common direction of rotation and the differential angular velocities of the Earth’s core and the Moon. The heat generated by the model explains the persistent molten state of the Earths core over a long geologic time, the nature of the deeper part of the geothermal gradient, and the non radiogenic heat emitted by the Earth. This heat is sufficient to drive all thermally-driven geodynamic processes that are of deep origin.”
http://www3.interscience.wiley.com/journal/120020443/abstract?CRETRY=1&SRETRY=0
Especially after finding this paper by;
Climate Change is Nothing New – By Emeritus Professor Lance Endersbee, AO.
“”As I write this a research ship is heading to a part of the Mid-Atlantic Fracture Zone where there is a huge gaping hole in the oceanic floor where the normal ocean crust seems to be missing. The ocean crust is normally about 6km thick, but in this place it is virtually nil.
>>It is claimed that the area of the hole is thousands of square kilometres in extent.<<
Without pre-judging the results of the expedition, it
is reasonable to anticipate that this area could be found to be another new source of high geothermal heat flow into the Atlantic Ocean.””
This is why I feel theres more that need to be taken into account and included in the maths equasion to make it believable.
The mountain range in question did not explode, it was built up much like the volcanos in the ocean that have been seen boiling the ocean surface. So the question then is if volcanos can boil the surface of the ocean then can they melt ice? Yeah I am pretty sure that is the case.
Jeff,
This post concerned this report of explosive volcanoes in the Gakkel Ridge. I am very interested (and skeptical) about any information you have concerning ocean bottom volcanoes “boiling the ocean surface.” Can you provide a link.
Best Regards,
Tom
I just remembered something else. In Antarctica, there is an underwater “dormant” volcano by Deception Island. The water in the caldera is apparently hot enough to scald you if you’re not careful, but people actually take a dip in the hot springs there. Check out this video:
“When Antarctica Was Green” http://www.geolsoc.org.uk/gsl/site/GSL/lang/en/page3155.html
(scroll down the page for the link to view)
You are ONLY using the thermal energy released during the erruption on ONE day 18May80. Also not factoring in the mechanical energy that ejected 0.67 cubic miles of material or the Lahars totaling 3,900,000 cubic yards of melted ice/snow and soil/rocks. Of that ONE day, that your were using to justify your ASSUMPTION.
The multible underwater volcanoes along the Gakkel Ridge have been active for 10+years. NOT just ONE day……..
Also you forgot to factor the Latent heat requirement to change the physical state of the ice into water. 144BTU of heat is required to change 5 pounds of ice to water or 3.34 x 105J/kg at 32 degrees.
Dear AC Robertson,
I am not “ONLY using the thermal energy.” of the Mt. St. Helens eruption in my calculation. I am using a common estimate for the TOTAL energy release by the Mt. St. Helens eruption. This includes the mechanical and thermal energy.
The daily activity in the Gakkel Ridge area is nothing compared to a full scale explosion. But what if the energy released in the Gekkel Ridge every single day for the last 10 years were equal to the energy of Mt. St. Helens on May 18th, 1980? That would still only be enough to melt 3.5% of the Arctic ice (assuming an average of 3 meters thick spread over 10 million square kilometers.
The number make is quite plain. This is not causing increased Arctic melting.
Best Regards,
Tom
While you’re all busy debating the amount of direct heat coming from these ‘eruptions’, have you considered the tremendous amount of ‘gas pressure’ required to affect them under such great depths? Gas pressure of such a magnitude would indicate magma coming from core depths .. along with phenomenal quantities of gas .. a large component of which is probably carbon dioxide. Whether by direct heat or percolating C02, there appears to be much potential here for natural warming of our biosphere!
I can see a number of flaws in your calculations and logic.
Firstly, the Mt. Helens eruption (which I had the privilege of watching) was working against less than sea level air pressure, and the majority of it occurred over a period of days.
The Gakkel ridge eruption was working against pressure many, many times greater than that of Mt. St. Helens. Your 24 megaton estimate is probably an order of magnitude off at least. There was a long period of earthquake activity where the quakes measured 4 – 6 on the richter scale
during the time of the eruptions. The eruptions created enough hot water
at a high enough temperature that the debris was carried far from the origin
– not by explosive energy, but by the velocity of the water. This would indicate a large temperature differential in order to generate velocities of this magnitude. If you look at the map of thin ice vs. lat. and long. the thinning lies directly over the Gakkel ridge. The ridge itself is over 1000 miles long,
with the sudden spurt of activity over a period of months, the heat release by earthquake, eruptions, lava flow (they found rocks that are normally found only very deep in the earths magma – again indicating tremendous releases of energy in order to bring them to the surface), and hot water vents, spread out over such a large area indicates a far larger release of energy then what you have estimated.
Also lastly, if global warming were true, then why is antarctica now at its greatest ice accumulation ever? If CO2 were responsible for global warming it would be affecting the antarctic as well – but clearly its not. And its not just antarctica either – while there are glaciers that are receding, many glaciers worldwide are growing, and the number is at least equal to those that are receding.
There is almost no statistical correlation between global temperature and CO2 levels. There is a much stronger statistical relation between sunspot activity and global temperature.
Lastly the data that is being used to support global warming is flawed.
The surface stations that are being used to record the US temperature history
are so poorly sited that there is a definite upward bias in the temperatures that they are recording. Go to http://www.surfacestations.org/ to see the sorry state of affairs. If it is this bad here, it certainly is far worse around the world.
Lastly it has come to light that for many socialist liberals, the desire for global warming to be true is so powerful that they are willing to perjure themselves – as is being revealed in “Climategate”.
Here is an example of data being manipulated so that it appears to match
this scenario that liberals so desperately want to be true:
Dear Kurt,
I appreciate your long comment.
However, The Gakkel Ridge question is quantifiable. If you followed the numbers, you saw that, roughly speaking, 1000 volcanos that release the same amount of energy as Mt St Helens would melt only about 1% of the ice that melts during the seasonal cycle.
Kurt, considering global warming in general, perhaps you should take a closer look at my blog.
Best Regards
ClimateSanity
How much energy does the Gakkel Ridge release per year? Has there been an increase in the geothermal energy released in the arctic region over the past 50 years?
I don’t think anyone actually knows the answers to these things. Indications are that the ocean surface temperature in the region has risen 1.5 to 2 degrees in that period. Would that have an effect on the amount of water vapor in the atmosphere, and perhaps the rate at which ice melts?
May I ask Kurt to name us the source of his following interesting statement: “If you look at the map of thin ice vs. lat. and long. the thinning lies directly over the Gakkel ridge.”? Thanks. With best regards, R.Schiesser (Univ of Naples, Italy)
First law of Thermodynamics: Energy is neither created or destroyed, but transferred.
People, the tremendous amount of energy that these volcanoes produce (Megaton Bomb amounts of energy) will be transferred to the closest physical sources surrounding them such as the water, the ice, and the land mass.
This amount of energy can easily lead to massive amount of ice melt in these areas.
You got to be very closed minded person to be stuck on this man made theory!
Brian,
Have you actually read this post or any of my other posts?
Just curious.
Best regards,
ClimateSanity
Mount St. Helens released 24 megatons
Krakatoa is equivalent to 200 megatons that quite an impressive explosion but even at that magnitude the math is still does not add up. But what about Flood basalt the two largest in recent time Eldgjá releasing estimated 18 km³ of lava and Laki estimated 14 km3 lava. of course the extreme example is the Siberian Traps.
Now I am not saying this is the cause. In fact i could not find any resource calming the existence of a flood basalt at the Gakkel Ridge. So proposing The question could a flood basalt on the ocean floor (at Gakkel Ridge) over a period of time generate a sufficient amount heat to raise the arctic ocean by one degree and if so what type of magnitude are we talking about. I know its a bit off topic thanks.
but the oil spill in the gulf of mexico will warm the waters leading to a bad hurricane season.
Huh?
The reason that scientists were able to “prove that bumblebees can not fly” is because conventional aerodynamic analysis methods simply don’t apply to insect wings.
Here’s the deal -some people who had a sophomoric understanding of how a conventional stiff airfoil-shaped wing, with steady state, or partially steady state, air flow analysis techniques, and lo and behold, the calculations did not work for the bee. Someone jokingly said, “I guess that proves bees can’t fly”, and they all had a good laugh. But, of course, they all knew it just proved that bee flight is too complicated to analyse with conventional airplane aerodynamic methods.
Also-we do not understand tornadoes. If incorrect analysis methods fail to accurately predict tornadoes, does that mean science has proven they don’t exist? (even if the math looks right)
Proving that the geothermal activity of the Gakkel ridge is not a major factor in the arctic ice melt??–and just like the bumblebee takes off–just so–the ice melts away.
I’m meeeeellltinggg
Dear wiseRILLIANTgenius,
yes, now I see your point. If you believe something to be true, and some calculation shows you to be wrong, then that calculation must be incorrect. How do we know this? Because you can find a calculation from a totally unreleated subject that was wrong.
QED
Thanks for the enlightenment.
Best Regards,
ClimateSanity
The same thought occurred to me as well. However showing that Mt. St. Helens didn’t cause the Arctic ocean to warm does not persuade to your point that it wasn’t warmed by causes which include geological ones, like the virtually unexplored Gakkel Ridge.
With roughly 60 active volcanoes inside the 10 degree line, the Arctic is one of the most geologically active regions on the planet. Why not attempt something more reasonable, and simply show how the ocean isn’t warmed by the atmosphere? Seems a better point to make.
With thanks and regards.
Scientists discovered the Gekkel ridge over SEVENTY years ago and no one knows for how long it’s been active prior to that. That makes for an awful of heat for an awful long time. Question! if the melting of the arctic ice is because of global warming how come the antarctic isn’t meltin at the same rate?
Joan.
You are implying a false dilemma. That is, either the Arctic is melting because of anthropogenic global warming, or because of volcanos in the Gakkel ridge. What about other, albeit more complicated, reasons?
Look at the math. “It would take a thousand volcanos the size of Mount St. Helens every year to account for just 1% of the yearly Arctic ice loss.
”
ClimateSanity
Apparently an adequate amount energy comes from somewhere. Is it your claim that it’s ‘sunnier’ at the North pole than the South pole? Why do Arctic glaciers melt from the bottom?
While the math is persuasive, and posters make some allowable points, I would like to point out that the real question is not AGW vs submarine volcanoes, but one more akin to prioritizing a list:
How much of the late 20th century warming was due to:
a. AGW
b. Land use
c. Solar effects
d. Oceanogrphic and Atmospheric Oscillations
e. Volcanoes
f. Milankovich cycles
g. Anything else?
I would be interested in reading other posters’ comments and estimates of this list. My current estimates:
a. AGW: [CG: 5-10%]
b. Land use [CG: 10-15%]
c. Solar effects [CG: ~>50%]
d. Oceanographic and Atmospheric Oscillations [CG: 25-30%, with important time-lag buffering of solar effects.]
e. Volcanoes [CG: ? The most important effects are short-term.]
f. Milankovich cycles [CG: Long-term effects only, so ~0% of 20th century effects.]
g. Anything else? [CG:?… moon effects? e.g. solar blocking, solar lensing, …. ]
If the question were specifically about arctic melting, then my estimates, after reading the articke and comments here, are:
a. AGW 0%
b. Land use 0%
c. Solar effects 25%
d. Oceanographic and Atmospheric Oscillations 75%
e. Volcanoes ~1% max
f. Milankovich cycles 0%
g. Anything else? ??????
The volcano example for the most part trivializes the problem. It is an example of one of several ways in which the Earth releases geothermal/radiogenic energy. Other mechanisms such as conduction, convection, and radiation are more productive examples. The average rate at which energy is radiated by the Earth’s core, mantle, and crust is estimated to be somewhat over 8 x 10^4 Joules per second per square kilometer. Over an area the size of the Arctic ocean, an amount of energy greater than a Mt. St. Helens eruption is produced every 3 hours.
This assumes it absorbs energy at the average rate for the entire planet. But it is well known that the Earth’s crust is considerably thinner in the area of the Arctic ocean. This is particularly true in the region of the Gakkel Ridge. And so, under such circumstances, it is reasonable that the rate at which energy is released into the Arctic ocean might be higher than average.
It is also worth considering that the Earth’s magma is not a homogeneous mass at a uniform temperature; there are hotter and cooler regions. It is also apparent that these regions are migratory over geological time periods. Repeated migration of hot spots near thin portions of the Earth’s crust might relate at least to one aspect of oceanographic and atmospheric oscillation. Over a period of a few years, moderate amounts of additional energy would be enough to raise the Arctic ocean by a degree or two.
Thank you for the comment.
Your value of 8 x 10^4 Joules per second per km^2 is correct. For the sake of simplicity, let’s round that up to 10^5. The Arctic Ocean is on the order or 10^7 km^2. So that is works out to 10^12 Joules per second over the entire Arctic Ocean.
Mt St. Helens released about 10^17 Joules of energy. Therefore it would take the 10^5 seconds (10^17 / 10^12) for the entire Arctic to receive from the Earth’s core the amount of energy released by Mt. St. Helens. That is 30 hours, not three hours. That is about 300 Mt. St. Helen’s worth of energy per year. But it would take a thousand volcanoes the size of Mount St. Helens every year to account for just 1% of the yearly Arctic ice loss. So, no cigar.
You say “Over a period of a few years, moderate amounts of additional energy would be enough to raise the Arctic Ocean by a degree or two.” The average depth of the Arctic Ocean is very close to 1 kilometer. Its area is on the order of 10^7 km^2. So its volume is about 10^7 km^3 or about 10^16 m^3 or about 10^22 cm^3. At 10^12 Joules per second it would take 10^10 seconds to raise the ocean temperature 1 degree C. That is about 300 years. Of course, this assumes that all of that added energy remains captured in the Arctic Ocean – none is carried away by currents and none is radiated out through the surface.
There is no evidence that I am aware of that the energy flux from the Earth’s interior into the Arctic Ocean has changed in any significant way in the last 100 years.
ClimateSanity
Your calculation assumes perfect mixing, since it assumes the entire volume of the Arctic waters are heated rather than very warm water over the smaller volcanic area rising quickly to the surface and spreading there, which is the much more likely behavior for water. The surface temps being a greater influence over surface ice extents than deep water temps. I dare say this flaw in your calculations is orders of magnitude more incorrect than the influence of currents etc.
Thanks for the math check, Tom. Yes, going back through it again it appears that the average amount of energy radiated by the Earth into an area the size of the Arctic Ocean equals the estimated energy released by Mt. St. Helens every 23 hours and change.
The point being overlooked is that the vicinity of the Arctic Circle is not at all average in its geothermal activity. While exact energy numbers are not known, and extensive research is currently underway, what is clear is that the region is one of the most active on the planet, and that it may have the highest geothermal gradients on the planet. Under such circumstances, energy output per unit area would be well above the planetary average.
In light of these facts, and given that the average Arctic ocean temperature has in fact risen 2 degrees C in the past 100 years, it is illogical to dismiss the possibility out of hand – such as you’re attempting to do.
[…] I’ve mentioned the Gakkel Ridge, Tom Moriarty of Climate Sanity, in Volcanos in Gakkel Ridge NOT responsible melting the Arctic ice, used the Mt St Helen’s eruption as a starting point. According to the U.S. Geological […]
Your calculation for melting ice makes sense. Now lets apply the same logic to heating the oceans.
Ocean volume: 310 million cu miles = 147 brillion cu. ft
Weight of 1 cu. ft of water: 62.4
Weight of World’s Oceans: 9.5 trillion lbs
Energy to raise 1 lb of water 1 deg F: 1055 joules
Energy to raise Ocean’s 1 degree: 1.0 E 16 joules
Energy from Mt St Helen size eruption:1.0 E17 joules.
So while a single eruption the size of Mt St Helen’s wouldn’t melt the Artic Ice, it would provide enough heat to raise the Artic Ocean’s temperature significantly.
Assume a series of on going eruptions to replace the heat taken out of the system by ice formation [the 334 joules mentioned earlier] and you could easily reach an state where there was a slight energy excess from volcanism, leading to decreased ice formation.
Seren,
Thanks for the comment.
However, your math has a few problems.
First, the volume of the oceans is 310 million cubic kilometers (km3) (not cubic miles, as you stated). This translates into about 74 million cubic miles, because one cubic kilometer is the same as 0.24 cubic miles.
There are nearly 150 billion cubic feet in a single cubic mile (5220 x 5280 x 5280 = 147 billion). You said the entire ocean’s volume was 147 billion cubic feet. That is off by a factor of 74 million.
Lets work it out using metric units
One cubic kilometer (1 km3) is the same as 1 billion cubic meters (1e9 m3) or one tillion liters (1e12 l) or one qaudrillion cubic cm (1e15 cm3).
If we ignore the fact that salt water density is slightly different than fresh water density, then we can translate from volume to mass. That is, we can say that one cm3 of ocean weighs 1 gram (1 g). So 1 km3 of ocean is equivalent 1e15 grams.
Consequently, 310 million cubic kilometers (3.1e8 km3) of ocean is equivalent to 3.1e23 grams (3.1e23 g) of water.
(3.1e8 km3) x (1e15 g/km3) = 3.1e23 g
The heat capacity of water is about 4.2 joules/g/degree C (4.2 J/g/deg). Therefore the amount of energy needed to raise the temperature of the oceans 1 degree C is…
(4.2 J/g/deg) x (1 deg) x (3.1e23 g) = 1.3e24 J = 1.3e24 Joules.
You said it would take 1e16 joules to raise the temperature of the oceans 1 degree. So, you were off by a factor of approximate 100 million
(1.3e24 joules)/(1e16 joules) = 1.3e8 = 130 million.
The energy of Mt St Helen’s was about 1e17 joules. Therefore it would take 13 million times the energy of Mt St Helen’s to raise the temperature of the ocean 1 degree C.
(1.3e24 Joules)/(1e17 Joules) = 13 million
It would take a Mt St Helens worth of energy dumped into the oceans every day for 35,000 years to raise the temperature of the oceans 1 degree C.
Now consider this:
The crossection of the earth is about 125 trillion square meters (1.25e14 m2). The solar energy flux from the sun at the top of the atmosphere is about 1300 Watts per square meter. That is the same as 1300 joules per second per square meter (1.3e3 Joules/m2)
So the total solar energy impinging on the earth at the top of our atmosphere is about 1.6e17 joules per second. Or about one Mt. St. Helens worth of energy every second.
Best Regards,
ClimateSanity
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Calculations notwithstanding, if one could show that undersea vulcanism actually did melt Arctic ice, as here…
http://www.climatechangedispatch.com/heat-from-deep-ocean-fault-punches-hole-in-arctic-ice-sheet.html
…then we should probably re-evaluate our model, no?