Guest Post by Steven Goddard
The Guardian image below taken this week near Iceland has the caption “Smoke and ash billows from a volcano in Eyjafjallajokull, Iceland Photograph: Ingolfur Juliusson/Reuters”
The Guardian caption is for the most part incorrect. Note that the volcanic cloud is largely indistinguishable from the other clouds, except for it’s shape. The reason for the similarity is that the vast majority of the volcanic plume is water vapour, not ash and definitely not smoke. Where would smoke come from??? There aren’t any trees on Iceland to burn.
The abundance of gases varies considerably from volcano to volcano. However, water vapor is consistently the most common volcanic gas, normally comprising more than 60% of total emissions. Carbon dioxide typically accounts for 10 to 40% of emissions.
70% of the earth’s surface is covered with water. Where did that water come from? It is generally believed that most of it outgased from the interior of the earth during the first 700 million years of the earth’s existence.
Steam from the interiorToday most authors believe that early steam from the hot mantle but already cool atmosphere, caused the oceans in the very early stages of the planet. They reason from studies of chondrites (space rocks) in space that under compression, enough water could be released to form an ocean. Today one can observe the gases escaping from active volcanoes, and these too contain water. In this scenario, the oceans would still be increasing in size, a gradual process that would never really end.The amount of water stored in rocks of the primary lithosphere is estimated at 25E21kg (Hutchinson G E, 1957), whereas the water in all oceans is 1.35E21kg, so it is quite possible that all this water emerged slowly after rocks were compressed and heated while the atmosphere had cooled already.
We know that the oceans could not have condensed out of the early atmosphere, because even a 100% water vapour atmosphere would only contain 10 metres of liquid water. People have hypothesized that the oceans came from comets, but the hydrogen isotope ratios in the oceans are different than that seen in comets Halley, Hyakutake and Hale-Bopp.
The only plausible origin of the oceans is from the interior of the earth. So why don’t we see oceans on other planets and the moon? Liquid water only exists in a narrow range of temperatures and pressures. Other planets are too hot, too cold or too small to hold liquid water, though some of the moons of the giant planets may have liquid water.
Why is the relationship between volcanoes and water important? Because steam pressure is the primary driver of explosive volcanic eruptions.
Below are some images of potentially explosive eruptions :
Mt. St. Helens 1980 : Mostly steam, some ash, almost no smoke.
The video above shows the moment of the big eruption May 18, 1980
Mayon 1984 USGS photo : Steam rising, ash cloud falling down the sides of the mountain.
Fourpeaked Volcano, Alaska 2006 USGS photo : 100% steam
Tungurahua 2006 NASA EO image : Steam, ash and lava
Eyjafjallajökull 2010 NASA EO image : Steam, lava, ice
Below are USGS images of non-explosive eruptions at Mauna Loa, Hawaii
Note in the image above that there is some smoke on the left side – from burning trees, and a little steam at the summit. So what is the difference between explosive and non-explosive eruptions? The difference is mainly due to the presence or absence of water. Water mainly enters volcanoes from two primary sources.
- Subduction on the sea floor, and transport upwards into a magma chamber. (Mt. St. Helens)
- Melt from snow and ice above. (Eyjafjallajökull and Mt. St. Helens)
Mauna Loa on the other hand has very little water mixed in with the magma, as it is neither near a subduction zone nor is it covered with snow most of the time. So eruptions from Mauna Loa tend to produce lava rather than steam and ash.
Looking at the mechanics, it becomes clear that explosive volcanic eruptions can not occur in the absence of large amounts of steam. Liquids (like magma) have very low compressibility and can not store enough mechanical energy to cause an explosion. Gases on the other hand are extremely compressible and can store vast amounts of energy. Steam has the unique property that it is liquid until it comes in contact with the magma (or the overburden pressure becomes low enough to allow it to switch to vapour phase) – then it converts thermal energy into mechanical energy very efficiently. The world used to run off steam engines based on this principle.
Most modern power plants still use steam to convert thermal energy into mechanical energy. Same principle that makes volcanoes explode.
That was a steamy expose’
What is the definition of ‘smoke’? I always thought is was the combination of water + CO2 + maybe other stuff (SO2, particulates, …).
Interestingly enough last night on a ‘discovery sunday’ episode called “journey to the center of the earth” Water in the mantle was discussed. It was claimed that water from the oceans went underground with the sub-ducting plates.
Don’t forget the brimstone (sulfur) that gets converted to sulfur dioxide! In any case, vulcanism is a gas.
So it looks like we’re headed towards Waterworld in a few million years. Better teach your kids to swim!
So rising sea levels from volcanoes?
Tom_R (18:43:09) :
Smoke is generally considered to be the by-product of incompletely burned fuel from a fire. There isn’t much in the way of fuel inside a volcano, as everything is already oxidized CO2 SO2 H20, etc. Few things would burn in the presence of all that water anyway.
Volcanoes often start fires after they erupt, but Iceland doesn’t have much in the way of fuel to burn.
The hydrogen isotope ratios in several comets are different from those of Earth’s oceans. Now that’s a worry as even if the oceans came from water in the interior of the Earth it surely all comes from the accretion disc around the early sun. There must be some isotope differentiation process in action. Or else we really don’t have much of a clue about this, the early solar system or the Earth at all.
This outgassing process of the water must surely also lend weight to Tommy Gold’s inorganic oil hypothesis as tarry substances have been detected on comets and will likely be found at the Moon’s poles. Some volcanos also emit methane it seems.
OT but interesting:
Just heard a news bulletin on ABC radio (government propaganda arm- aka Always Been Communists) here in Australia. Lufthansa and Air France are annoyed that the aircraft grounding in Europe was done solely on the basis of a computer simulation. !!! Now on what basis is the proposed restriction on CO2 emission based???
The cloud in the first illustration is high and cold enough to cause droplet condensation from explosive dust particles to form Pyrocumulous clouds http://wapedia.mobi/en/Pyrocumulus_cloud
Having dinner with the Apostle Peter was probably interesting, especially when he went, as my kids would say, a bit ‘Random’:
‘……the earth was formed out of water and by water…’ 2Pe Ch3v6
Thanks Peter for that. Could you pass the bread please.
Very interesting and educational post Steve! Learned a lot about a lot.
This site is becoming addictive. Endless brain candy.
Brutal comment noting the lack of fuels to produce smoke in Iceland. Common sense strikes again…
From NASA’s web site….
Title: Water in the Early Earth
Authors: Abe, Y.; Ohtani, E.; Okuchi, T.; Righter, K.; Drake, M.
Publication: Origin of the earth and moon, edited by R.M. Canup and K. Righter and 69 collaborating authors. Tucson: University of Arizona Press., p.413-433
Publication Date: 00/2000
Origin: LPI
Bibliographic Code: 2000orem.book..413A
Abstract
In this chapter we discuss the behavior of water in the early Earth. Earth likely formed through accretion of water-bearing planetesimals. An H2O-rich proto-atmosphere should have formed during accretion by degassing from planetesimals and/or gravitational attraction of solar-nebula gas, and it may be a direct ancestor of Earth’s present atmosphere-hydrosphere. A hydrous magma ocean can form in response to the thermal blanketing effect of an early proto-atmosphere. The presence of water in a magma ocean
lowers the liquidus and solidus temperatures, affects phase relations, modifies mineral-melt and Fe-melt elemental partitioning, and alters its physical and thermochemical properties. In addition, because of the presence of water, a large amount of H may be partitioned into metallic Fe under high pressure and delivered to the core. Under plausible water concentrations in source materials, H can reconcile a major fraction of the observed density deficit in the present core. Many hydrous magnesian silicates are stable at pressures equivalent to those in Earth’s transition zone, and the mantle may have long-term water storage capacity. Evidence for a hydrous Archean mantle is provided by experimental work demonstrating the ability to generate komatiitic magma by melting hydrous peridotite…..’
There is an organization that I aspired to go to one of their meetings as a Chief Stationary Engineer … that is BLRBAC (Black Liquor Recovery Boiler Advisory Council) whose sole purpose is to prevent these catastrophic water to steam (instantaneous) explosions from occuring. Primary protection system is the rapid drain system which trips the boiler and drains the 13 story boilers wall tubes down to just 8 feet of water. Many people were killed by that 1800 times expansion from water to steam in the early days of Recovery Boilers.
Now I’m into burning coal and saving plants from being so efficient at sequestering their primary nutrient. Don’t tell my employer that’s my take on things, their’s money to be made (taken) in refrigerating flue gas and putting it underground for advanced ‘oil field’ recovery and just because we can do it … and those windmills with special disruptive destabilizing access to the grid.
Mauna Loa? Do you mean Kilauea? maybe not, but Kilauea spews some gasses-
http://hvo.wr.usgs.gov/archive/spotlight_images/20081114_0041_L.jpg
THis from Brian Cox’s Solar program on BBC2 goes into water plumes on one of Saturn’s Moons..Encelidus (sp?) as found by Casini. The heat on Encelidus is caused by eliptical interactions with saturn and it’s affect on the tectonic plates on Encelidus; heating the plate locals up, which heats the water, which causes…..volcanoes of water. …..FYI.
In any case, Hawaiian volcanoes are from a ‘hot spot’ and very fluid, which in the past has been the explanation why they were not explosive.
Druid (19:39:58) :
Mauna Loa is the primary active volcano on Hawaii. Kilauea is the volcano located near the visitor center of the National park.
http://www.soest.hawaii.edu/GG/HCV/mloa-eruptions.html
Phil’s Dad (18:58:38) :
Most of the water in volcanoes is recycled, but the volume of water on the surface has increased over time. The bulk of the oceans formed during the first 700 million years of earth history.
Druid (19:49:17) :
Iceland is also a hot spot, but is generating a plume of steam and ash which Hawaii rarely does.
Interesting that outgasing theory…
Noah’s flood in Gensis 7:11 … all the fountains of the great deep broken up, and the windows of heaven were opened.
And a Jewish commentary on the text, the Midrash, p. 14 – indicates that it was scalding water that washed away the land lubbers…
The usual commentary is that there was no rain before this event, because the ‘rainbow sign’ is given later – so Noah’s family may have never had seen one before.
I’d also speculate that this could have been the start of the Supercontinent breaking up.
Vulcanologists attribute fully a quarter of the Earth’s atmosphere to volcano eruptions. Most also believe that not only water, and other gases, but methane is largely from geologic origins, rather than biologic. In fact most vulcanologists, like astrophysicists, believe that climatologists are dolts. But funding and research means supporting AGW.
Mauna Loa is the primary active volcano on Hawaii. Kilauea is the volcano located near the visitor center of the National park.
Sorry, guess I missed the point…
Mauna Loa is the largest ACTIVE volcano on Hawaii. Last eruption was in 1984. However, it is largest active volcano and mountain in the world too.
Let me look over about 15 miles to the South here- Yup Pu’u O’o has been flowing for pretty much constantly for the last 25+ years.
Granted that the commonplace ‘definition’ of smoke isn’t accurate, however on some occasions during this eruption there has been plenty of ash.
http://inapcache.boston.com/universal/site_graphics/blogs/bigpicture/eyja_04_15/e16_23020943.jpg
Eyjafjallajökull, unfortunately, is located in region with abundant water, waiting to become steam.
I hope, it doesn’t continue to evolve as an active volcano, the threat to the climate, at least of Northern Europe is no laughing matter.
And what happens if a volcano is fed Salt water instead, would its chemical reactions split the Chloride and Sodium? I can imagine the outgassing would be pretty spectaculary bad, if that was the case.
Good Luck Europe.
Mike Borgelt – funny how the Met Office advice to NATS (National Air Traffic Services) has been omitted from almost all media coverage:
19 April: UK Daily Mail: Operation volcano! Navy armada ready to pick up thousands of stranded Britons after France scuppers DIY rescue mission
By Vanessa Allen and Ray Massey
The Met Office defended its forecasts and said its own test flight had detected volcanic dust at levels which would cause aircraft damage.
Transport Secretary Lord Adonis said he expected ‘continuing disruption’ and said all test flight data would be handed to international safety authorities.
Two major aviation bodies also questioned the flight ban. ACI Europe and AEA, which represent most of Europe’s airlines and airports, said volcanoes erupted around the world without triggering the kind of restrictions imposed in Europe…
http://www.dailymail.co.uk/news/article-1267116/Operation-volcano-Navy-armada-ready-pick-thousands-stranded-Britons-France-scuppers-DIY-rescue-mission.html?ITO=1490
18 April: NYT: JAD MOUAWAD and NICOLA CLARK: Airlines Press Europe to Ease Ban on Flights
Airlines complained that European governments were overreacting to the threat, relying on incomplete data from computer models rather than real-world safety tests in the air above Europe..
http://www.nytimes.com/2010/04/19/world/europe/19ash.html?src=me
and again..
18 April: German airlines question extended flight ban
“The closure of the airspace has been imposed solely on the basis of data from a computer simulation from the Volcanic Ash Advisory Centre in London,” Joachim Hunold, head of Air Berlin, told the paper.
http://www.thelocal.de/national/20100418-26615.html
Met Office: London Volcanic Ash Advisory Centre
http://metoffice.com/aviation/vaac/london.html
johnythelowery (19:29:37)
You aren’t going far enough back.
Matt B (20:02:45)
You’re closer, but still not there.
GE 1:1 In the beginning God created the heavens and the earth. 2 And the earth was formless and void, and darkness was over the surface of the deep; and the Spirit of God was moving over the surface of the waters. (NASB) He created light and separated the light from the darkness. This was all on the first day of creation. Five more days and He had finished creation. This all occurred a little more than 6,000 years ago.
I keep hearing that one volcano produces more CO2 than all the cars ever made have, but others have said that is not true, which is correct?
Some great Iceland volcano pics: click
With regards to the ash plume modeling, at least one of the numeric models of the Icelandic plume uses SO2 emissions as a proxy for ash – rather than modeling ash dispersal directly.
I’m not sure of the emission relationship between ash and SO2, but I’m pretty certain that the dispersion patterns are quite different. However there must be enough SO2 emissions to make it worthwhile – perhaps for initial airborne measurements?
Other experts promise all the water came from comets and ignored volcanoes. I am so confused.
Amusing and interesting article about how the ‘science’ of water vapour forcing was derived. Basically just a fudge to fit some figures, no science involved!
http://climaterealists.com/index.php?id=5563
stevengoddard (19:02:34) :
but Iceland doesn’t have much in the way of fuel to burn.
But they’ve got plenty of hot girls. That’s a different fuel though.
My favorite definition of an expert is “some guy from out of town”.
johnythelowery (19:29:37) :
Having dinner with the Apostle Peter was probably interesting, especially when he went, as my kids would say, a bit ‘Random’:
‘……the earth was formed out of water and by water…’ 2Pe Ch3v6
Thanks Peter for that. Could you pass the bread please.
Now THAT was funny. I don’t think I completely understood it but nonetheless, I’m laughing quite vigorously. Thanks
Walter M. Clark (20:33:36) :
The word ‘day’ in Genesis 1 is a mistranslation. It is the word yom. It means ‘time period’. Yom is commonly translated day because a day is a time period of 24 hours, and is the correct translation of yom in many cases. But there are other time periods: supereon, eons, eras, periods, epochs, ages, decades, years, months, weeks, etc. So it wasn’t 7 days but 7 time periods (maybe like Hadean/Archean, Paleo-proterozoic, Meso-proterozoic, Neo-proterozoic, Paleozoic, Mesozoic, Cenozoic). There is no disagreement between accurate translation of the scriptures and science. 🙂
That’s all the farther I’ll go on this because I don’t want to debate it, and I think there’s something in the rules here about not debating religion. I just wanted to present the idea to you.
BBC article about a water foot prints and a “Perfect Storm” and embedded water usage. Its all much worse then we thought, and its time we all radically changed our lifestyle or else…
http://news.bbc.co.uk/2/hi/science/nature/8628832.stm
johnythelowery (19:48:50)
I have read that there is meant to be lots of water on/in the asteroid Ceres too. Probably no vulcanism though.
“The reason for the similarity is that the vast majority of the volcanic plume is water vapour, not ash and definitely not smoke. Where would smoke come from??? There aren’t any trees on Iceland to burn.”
Maybe nitpicking, but let’s remember: clouds don’t consist of water vapour. It is water. Aerosol.
So is there or is’nt there an ash cloud over Europe? Reading this and reading about the test results from Lufthansa I get the distinct impression the Met Office models have struck again. Wonder if the airlines will be able to bill them for the bogus ban, if indeed it turns out to be bogus? Not flying in the immediate vicinity of a volcanoe I can understand but 2-3000 miles away? WUWT?
I wonder how much of our climate will change, will it be another cold NH summer and winter? Mt St Helen cooled us a bit, what will this erruption do? Maybe we will see iceskating on the river again.. heh.
http://www.swisseduc.ch/stromboli/perm/iceland/eyafallajokull_20100416-en.html
Best photos so far of eruption, check out the galleries!!
What’s the point of having a computer scientist regurgitate Wikipablum when volcanologists offer more professional geophysics commentary ?
An honest tar sand miner could unearth more and better data and link in an hour’s harrowing of the GSA, which hsa published literally volumes on explosive eruptions.
Phil. (20:09:43) :
Ash is formed by violent interaction between magma and water, which cools, solidifies and fragments the magma into small particles. It is another by-product of water interacting with magma.
The city of Los Alamos, NM is built on top of hundreds of feet of volcanic ash from a super volcano eruption about a million years ago.
http://en.wikipedia.org/wiki/Valles_Caldera#Geology_and_science
The Long Valley Caldera in Mammoth, California is similar, and started showing signs of resurgence about the same time as Mt. St. Helens erupted.
http://en.wikipedia.org/wiki/Long_Valley_Caldera#Caldera
EU – “EU emergency talks called on volcanic ash air chaos”
“Sixty-three thousand flights have been cancelled in the four days…”
And these people think they can control the Earth’s climate by shaving a small percentage of Co2 from that trace gas Co2. Ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha.
http://news.bbc.co.uk/2/hi/europe/8628867.stm
Anyone worked out how many tonnes of Co2 have been emitted so far?
Will the airline companies be claiming/selling carbon credits because of the grounding of their aeroplanes?
There does appear to be exposed water ice in patches on the dwarf planet Ceres. I eagerly await the Dawn mission getting there.
Yom with a number and “evening and morning” is always a 24 hour period.
The culprit behind The Wasteland in the Matter of Britain is thought to be either an asteroid impact, a comet airburst, a major eruption in Indonesia – or this particular volcanic complex in Iceland. The dark ages really were dark. 20-25 years without a summer, famine afflicting the grain farming Romano-British and Romano-Gauls, along with plague, the Germanic tribes living differently not so severely decimated, along with the Muslim conquest of Rome’s bread basket and trade routes collapsing the economy until significant recovery began in the 9th century thanks substantially to Alcuin of York (Lindisfarne, actually)
Steve,
Here’s my layman’s (i.e. not an igneous petrologist) view of water and volcanoes.
Water (and other volatiles) are constituents of all magmas. We know this from the nearly ubiquitous presence of fluid inclusions trapped within and between mineral grains in igneous rocks. These inclusions are sort of like the ones in glacier ice that are used to identify the compostition of the atmosphere in the recent past. In this case, the inclusions indicate the relative composition of the volatiles which, in theory, were homogenously mixed with the components of the silicate minerals in the melt at the time when the rock cystallized. These inclusions contain volatile constituents (H2O, CO2,Cl2,SO2,etc) and other incompatible elements that weren’t incorporated into the silicate minerals which make up the rock.
We also know that basaltic magmas, like Hawaii, are higher temperature, lower viscosity and have a lower volatile content than the continental, rhyolitic magmas. In fact, the existence of lower temperature rhyolitic Cascade-type magmas are only possible because of the presence of the volatiles. Anhydrous silicate melts have somewhat higher melting temperatures. When volatiles are added, the temperature of the melting point is lowered analogous to the way salts lower the melting temperture (or freezing point) of water. My understanding of the relatively greater explosive potential of Mt. St. Helens type magmas is due to higher amounts of volatiles combined with higher viscosities resulting from the lower magma temperatures.
Is it possible to exclude any natural event on Earth from the effects of man-made “global warming”? Not according to AGW fanatics.
Now we have the prospect of “man-made” volcanoes, earthquakes and tsunamis, according to British scientists.
This is from today’s Telegraph:
http://www.telegraph.co.uk/earth/environment/climatechange/7604188/Volcanic-ash-cloud-Global-warming-may-trigger-more-volcanoes.html
“Volcanic ash cloud: Global warming may trigger more volcanoes
Climate change could spark more ”hazardous” geological events such as volcanoes, earthquakes and landslides, scientists have warned.
“In papers published by the Royal Society, researchers warned that melting ice, sea level rises and even increasingly heavy storms and rainfall – predicted consequences of rising temperatures – could affect the Earth’s crust.”
“…The increase in seismic activity could, in turn, cause underwater landslides that spark tsunamis.
A potential additional risk is from ”ice-quakes” generated when the ice sheets break up, causing tsunamis which could threaten places such as New Zealand, Newfoundland in Canada and Chile. The reduction in the ice could also stimulate volcanic eruptions, according to the research…”
And our old friend the “tipping point” makes its reappearance here…
“…Other impacts of rising temperatures include glacial lakes bursting out through rock dams and causing flash flooding in mountain regions such as the Himalayas, as well as rock, ice and landslides as permafrost melts.
And he said there may be ”tipping points” in the geological systems, where the crust reaches a threshold that causes a step-change in the frequency of such events – but it was not clear where those thresholds might lie.”
Yes, it’s all our fault. If only humans didn’t exist, the whole Earth would be one gigantic paradise full of birds, butterflies and frolicking dolphins, and completely unaffected by any geological event, ever. What these guys know about the Earth’s geological history can be written on the back of a postage stamp and still leave room for the Gettysburg Address.
@Walter M. Clark (20:33:36)
————————————————————–
GE 1:1 In the beginning God created the heavens and the earth. 2 And the earth was formless and void, and darkness was over the surface of the deep; and the Spirit of God was moving over the surface of the waters. (NASB) He created light and separated the light from the darkness. This was all on the first day of creation
————————————————————–
“separated the light from the darkness”
Waste of time imho, why not remove the darkness _before_ creating light ??
…and why work in the dark ? – I would create light as the very first thing
Most of the volcanic ‘smoke’ is actually volcanic ash (essentially very fine rock), which appears to actually be raining down from the downwind part of the cloud in the top picture of Eyjafjallajokull. But then normal smoke is also composed of particulates and often steam if burning wet wood. “Volcanic smoke” is a commonly used term, even if it does not refer to combustion.
Hawaiian volcanoes are basaltic, and thus much lower viscosity than the andesitic volcanoes on continental margins. But there are occasional explosive eruption on Hawaii when groundwater mixes with the magma.
Oeuf en visage, je peur. Steam is invisible, as is water vapour. What you see in clouds and the volcano plume is water droplets and/or ice crystals. Common parlance is wrong when referring to what is visible at the end of the jet of invisible steam issuing from a kettle as ‘steam’.
Tom T (20:35:02) : “I keep hearing that one volcano produces more CO2 than all the cars ever made have, but others have said that is not true, which is correct?”
I suspect that in this particular case, the one volcano loses to all the cars, but I haven’t done the sums.
http://www.skepticalscience.com/argument.php?p=4&t=236&&a=28
“Volcanoes emit around 0.3 billion tonnes of CO2 per year. This is about 1% of human CO2 emissions which is around 29 billion tonnes per year.”
This is an unreliable source, but in this particular case I have no reason to doubt it. Of course, it still has to be broken down for the actual question, but their figures suggest that the single volcano might lose the contest.
I do find it interesting that they go on to say “In fact, the rate of change of CO2 levels actually drops slightly after a volcanic eruption, possibly due to the cooling effect of aerosols.“. They do love those aerosols when there’s cooling. They may be right, but it seems rather obvious to me that when there’s a major eruption, the blocking of sunlight cools the oceans which then absorb more CO2. Is all the blocking done by aerosols? I don’t know, but mine seems to be the simpler explanation.
A couple of glasses of Brennevin (Black Death) and all will become clear in the following joke from an Icelandic friend:
The economy has died, been cremated and its ashes are being scattered all over Europe.
I do hope that all these references to Genesis, the Bible etc. are a joke, yes? Here in the UK we’re often told about the USA’s ‘problem’ concerning religion (like no Senator being atheist, or the film [movie] ‘Darwin’ being released everywhere across the globe, but not in the US). It doesn’t tend to figure in scientific debate over here, so are some commentators here on this forum having a little laugh, or are they serious?
Note to moderator: Please note that this post isn’t about religion per se, but about comments being made on the subject of water.
Here’s Eyjafjallajökull’s webcam.
http://eldgos.mila.is/eyjafjallajokull-fra-valahnjuk/
It’s quietened down a lot now.
Looks like plenty of ash from this volcano to me: http://www.nasa.gov/images/content/444588main_icelandvolcano-20100615.jpg
http://www.flickr.com/photos/gsfc/4530571303/
What does this mean for the Yellowstone super volcano.
Bad news if you’re a Discovery Channel documentary producer, looking to make a low budget feature.
Good news for the Heartland of America though.
I heard an interesting take on the disruption of the Icelandic volcano on BBC radio today. It said:
“Good news for the carbon budget with all of those grounded planes.”
Eh?
I wonder what they think comes out of volcanoes?
Plenty of ash spewing out of that Icelandic volcano from what I saw on the TV last night. I wouldn’t be too sure that the “steam” has actually come out of the volcano anyway – as there is a lot of cloud there is a lot of water vapour on the vicinity – could be the water vapour in the air is condensing around fine ash.
By the way, flights were stopped not due to a computer simulation but on the basis of test flights with small propellor aircraft that went up to collect ash samples. As a regular flier I’m not sure I want to put flying in ash to the test myself – those small particles of pumice probably don’t do a jet engine much good. They may find that opening up flights won’t result in a rush of people queuing to buy tickets!
Thanks for another excellent post Steven, got me thinking again!
I read somewhere that there is evidence of water being made in the upper atmosphere due to chemical processes. I suspect that weathering of rocks and other chemical processes also produce water.
Regarding the climatic effects of eruptions, the gases/ash produced seem to be heavily ionised and this would increase their effectiveness to act as nucleation centres for precipitation.
Good picture of the electrical effects here:-
http://davidthompson.typepad.com/.a/6a00d83451675669e20133ecc09b5f970b-800wi
So sorry Steve,but didn’t you know Iceland is too far north for volcanoes(Sanchez,CNN).???? What are you going to say when we figure out Antartica is the most active volcanic region in the world?/sarc off
I understood that volcanic activity has an effect on climate, not ‘tother way about. In today’s Guardian, a writer is pleading for funding to enable scientists to study the threat that climate change is to increased volcanic activity so that, eventually, those scientists may save the world..
I also understood that the same newspaper has a ‘Science Editor’ who has some scientific qualifications. Does he not proofread the mad stuff his staff hand in, or does the Guardian have a New Science agenda?
fhsiv (23:54:33) :
The viscosity of magma is largely dependent on the amount of volatiles, like water, mixed in. Icelandic basalt is similar in composition to Hawaiian basalt, but we don’t see much steam or ash coming out of Hawaiian volcanoes.
Matt (01:54:56) :
Places where the plume is dark is indicative of the presence of ash. Ash is much more dense than air, and would not rise upwards very far unless it was being lifted by hot gases, like steam.
The Mt St Helens eruption was interesting because you could see large amounts of ash falling back to earth out of the rising plume. And note in the Mayon image above, you can clearly see that the darker material is tending to move downwards while the lighter material (mostly steam) is moving upwards.
Alexander (04:05:48) :
I saw that Guardian article and practically choked. Some former scientist appears to have sold his soul.
Tenuc (02:49:06) :
A rising plume of very hot gas and ash generates a lot of friction, and thus charged particles and lightning.
Steven,
Science rarily digs deep enough for the imporatant questions and science is rare to be correct. Huge areas of our basic knowledge are missing with theories that put under pressure fall apart.
Mass under high enough heat can burn and turn into a gas and ash. Our core made of nickel? And taking 2 billion years to form? Did we not have gravity and electrical field them? Moon slows the planet? Gravity is created from mass?
NO!
All these areas deal with understanding the relationship of rotation to gases and mass. Science lumped both together but there properties are totally different. Just the basic understanding of rotation is an extremely complex area that shows how mass can be compressed and the interaction of energy.
Why after 4+ billion years, we still have quakes and volcanoes? When pressure is released, the energy should be gone but it builds up again over time, why?
Only concept we have of our interior is from reading of earthqukes to the density of the interior.
The only explanation that fits all areas is that our core is super compressed gases like the sun that can take high pressure and emmense heat. When rotating mass, the centrifugal force forces mass to the outside(in our case the mantle and crust). When the planet slows, the gases expand minutely, keeping pressure building under the crust.
In the universe, gases are the most abundant and everything rotates and is moving.
Thanks Steve good work.
I think big oil had something to do with this eruption…maybe they were doing that horizontal drilling and caused the eruption….they are hoping the ash will temporarily reverse the effects of AGW long enough so people will forget that CO2 is EVIL!!!! (sarc off)
Einar Kjartansson, a geophysicist at the Icelandic Meteorological Office explains what is happening :
http://www.reuters.com/article/idUSLDE63H0OV20100418?type=marketsNews
Look away if you come out in a rash when you hear anything related to the bible
and I agree, this is not the place for a religion discussion. Having said that…..
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Walter M. Clark (20:33:36) :
johnythelowery (19:29:37)
You aren’t going far enough back.
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Actually, I wasn’t going forward far enough. As what Peter really said was
‘….the earth was formed out of water and by water. By these same waters also the earth was deluged and destroyed!…..” 2Pe Ch3v6
As the ‘deluge’ referred to is Noah’s—which possits a flooding to the ‘top of highest mountain-(yes, i know)–it was quickly falsifiable by the volume of water needed let alone other problems. Not anymore. ‘……..The amount of water stored in rocks of the primary lithosphere is estimated at 25E21kg (Hutchinson G E, 1957), whereas the water in all oceans is 1.35E21kg, so it is quite possible that all this water emerged slowly after rocks were compressed and heated while the atmosphere had cooled already….’
What ever Peter was trying to say, with his mouth full, was some primary role of water in the formation of the earth which i feel is counter intuitive and appears to be true. But, that’s it. Sorry. Shouldn’t mention this. People are aware of Genesis but not Peter’s remark (we can discuss Bart Ehrman’s take else where…and Dawkins). Thx.
Ac
The early atmosphere could have contained all that water if it were much denser and hotter. Don’t you think It probably was when the surface of the earth was still molten.
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Maybe nitpicking, but let’s remember: clouds don’t consist of water vapour. It is water. Aerosol
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This is interesting (to me)…….a H2O molecule and a …..what is Aerosol?
(I can feel the Solar issue standing in the back ground)
Joe (05:01:11) :
The energy source which drives earthquakes and volcanoes is mainly radioactive decay of Uranium and Thorium inside the earth.
What if the water cycle is not closed but opened?. Cosmic rays, as during solar minimums (mainly composed of protons-90%-, which, btw, we must remember are Hydrogen Nucleii), then these react with ozone to produce water 2H+…O3=H2O+O2.
Remember Aquarius, the constellation depicted as a girl pouring down on earth a jug of water?, well, a japanese satellite has discovered a big source of cosmic rays (aka: protons 90%) in that direction. Curious, isn´t it?
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THis from Brian Cox’s Solar program on BBC2 goes into water plumes on one of Saturn’s Moons..Encelidus (sp?) as found by Casini. The heat on Encelidus is caused by eliptical interactions with saturn and it’s affect on the tectonic plates on Encelidus; heating the plate locals up, which heats the water, which causes…..volcanoes of water. …..FY
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What I find interesting is that the infra-red scans of Encelidus revealed that the tectonic plates where heated. It was felt the center of Encelidus had long cooled down. As the earth mantal rises with motions of the tidal effect (LHC has to accomodate this effect) perhaps it is the phenomenon that heats the magma we see in volcanoes in localized areas as in Encelidus. What proof do we have that the center of the earth is molten to the core? Molten at the area of plates, heated by friction from the plates moved by the tidal effect? I’m going to get some protective clothing on now and wait for the answers!! 🙂
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Walter M. Clark (20:33:36) :
johnythelowery (19:29:37)
You aren’t going far enough back.
Matt B (20:02:45)
You’re closer, but still not there.
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I’m definately a ‘yom’ guy as explained by someone else here.
Re: Tom T (20:35:02) :
I keep hearing that one volcano produces more CO2 than all the cars ever made have, but others have said that is not true, which is correct?
—
I’m pretty convinced we produce more CO2 than volcanoes, but also the amount of volcanic CO2 may be underestimated, and same may be true for frequency. For example-
http://www.volcano.si.edu/faq/index.cfm?faq=06
So what counts as an eruption for estimating CO2 output given there’s lots of venting ongoing without eruptions. It seems to me to be one of those areas where we’re still discovering a lot and our ability to observe and measure is improving. To make things ever more complex, the chemistry in a volcano can change over time. Isotope analysis does show we produce more than they do though.
They are one of those things though where I sometimes wish I could go back in time and pick a career in geology as it seems we’ve still a lot to learn about volcanoes.
“The abundance of gases varies considerably from volcano to volcano. However, water vapor is consistently the most common volcanic gas, normally comprising more than 60% of total emissions. Carbon dioxide typically accounts for 10 to 40% of emissions.”
Well, then, look for a spike in temperatures in coming months. As CAGW proponents have told us over and over, more CO2 equals more greenhouse effect equals higher temperature. It’s quite simple really. What more do you need to know. You can prove it with a glass jar in a lab.
What? History shows volcanic eruptions cause cooling? But what about all that CO2? I guess it might be more complicated than that, huh?
Is it just me, or are the Brits being rather fussy and skittish about all this? I have yet to see anyone state that they have direct evidence of ash clouds but rather they seem to be relying on computer simulations. I even heard one “authority” state that the test flights are in no way adequate to re-open British airspace.
I also note with approval that British Airways CEO BA Willie Walsh will be on its test flight. Bravo!!
Maybe I’m just a cowboy, but if an airline and its passengers agree to lift off, then I’m OK with that. No nannies needed.
stevengoddard (04:48:44) :
The viscosity of magma is largely dependent on the amount of volatiles, like water, mixed in.
Actually, the viscosity of the magma is dependent on the amount of silica (SIO2) in the magma.
Low silica = fluid flow (basalts – Hawaiian volcanoes)
High silica = sticky magma/explosive (rhyolites – Mt. St. Helens)
This volcano’s ash, at the moment, is andesitic in composition (57-58% silica).
http://scienceblogs.com/eruptions/2010/04/eyjafjallajokull_eruption_cont.php
I’m not positive, but I think much of the ash is being produced by explosive mixing of glacial ice melt with the rising magma. That would also produce copious amounts of steam/water vapor.
Steven:
Right. The ash gets entrained into the steam and other rising gases, but once the steam cools downstream from the volcano, its the ash particles that make the plume visible. The particles that are left are small enough to become suspended in the air, and can remain aloft for years.
Comets are not made of ICECREAM That’s what the New Age post normal astronomers thought. The NASA “Deep Impact” probe, proved it was wrong:
http://www.thunderbolts.info/tpod/2006/arch06/060214comet.htm
The latest value : 13,768,594 km2 (April 18, 2010)
Paul Hildebrandt (06:57:49) :
Silica rich magmas melt at much lower temperatures than basalt magma -partly because of the presence of water. Their lower temperature makes them more viscous.
“The presence of even 0.8% water may reduce the temperature of melting by as much as 100 °C. ”
http://en.wikipedia.org/wiki/Magma
Madman (06:55:55) :
The fact that the ash didn’t bring down a plane on it’s first flight, doesn’t mean that the accumulated damage over 100 flights won’t significantly increase the odds of engine failure.
enneagram (07:20:06)
Interesting read in your link. What does it mean??? What are it’s implications??
Matt (07:01:07) :
I can see clouds and jet contrails just fine, without any ash.
kcom (06:36:17) :
Global temperatures will rise over the next few months because of the NH summer, but anomalies should drop as ENSO goes negative into the summer. The volcano won’t have much affect on temperatures.
Steven:
You see clouds and contrails because there are CCNs or other aerosols present for the water vapor to deliquesce onto. You’re not seeing ‘steam’ as you put it.
johnythelowery (08:12:14) Well, this leads you to a real science breakthrough, a new paradigm, which btw, reveals itself as a universal “key”, which contrasts with a purely flintstones’ universe conception, derived from Newton a man who saw the apple falling but forgot to see, above, the apple tree growing:
http://www.holoscience.com/index.php
stevengoddard (08:08:46) :
Silica rich magmas melt at much lower temperatures than basalt magma -partly because of the presence of water. Their lower temperature makes them more viscous.
Andesitic magmas usually erupt as blocky lavas.
http://www.geology.sdsu.edu/how_volcanoes_work/andesiterhyolite_lava.html
I’m not having an issue with whether there is water in the magma or not. What I’m having an issue with is whether or not the ash is being produced by the water in the magma (doubtful, not enough gas present, water or otherwise) or by the interaction of the magma with the glacial meltwater and/or groundwater.
“The presence of even 0.8% water may reduce the temperature of melting by as much as 100 °C. ”
That is true. However, your reference above is in regard to the formation of magma by melting of the parent rock. This is where the water is introduced into the magma and the reference is valid. Not at the surface, where it is being expelled.
This explains it much better detail. It’s known as a hydrovolcanic eruption:
http://www.geology.sdsu.edu/how_volcanoes_work/Hydrovolcanic.html
A senior Iranian cleric says women who wear revealing clothing and behave promiscuously are to blame for earthquakes.
‘Many women who do not dress modestly … lead young men astray, corrupt their chastity and spread adultery in society, which (consequently) increases earthquakes,’ Hojatoleslam Kazem Sedighi was quoted as saying by Iranian media.
Women in the Islamic Republic are required by law to cover from head to toe, but many, especially the young, ignore some of the more strict codes and wear tight coats and scarves pulled back that show much of the hair.
Read more: http://www.dailymail.co.uk/news/worldnews/article-1267262/Iranian-cleric-Women-wear-revealing-clothing-cause-earthquakes.html#ixzz0lYwFmU4m
Here we have it. Now it is the fracturing coupled with plate tectonics that creates a weak spot in the crust.
Paul Hildebrandt (08:54:25) :
Reposting, for you:
Paul Hildebrandt (08:40:27) :
I am assuming that you read my article above the comment section?
With all European air traffic grounded you have to hand it to the brave souls who risk their lives to bring us such beautiful AERIAL photos of this eruption.
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enneagram (08:32:31) :
johnythelowery (08:12:14) Well, this leads you to a real science breakthrough, a new paradigm, which btw, reveals itself as a universal “key”, which contrasts with a purely flintstones’ universe conception, derived from Newton a man who saw the apple falling but forgot to see, above, the apple tree growing:
http://www.holoscience.com/index.php
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…….um……what does?
Here’s a pretty stunning photo of the eruption:
http://i.imgur.com/U7UY1.jpg
As far as steam being a component of the explosivity, this very much echoes what our (Icelandic) volcanologists have been saying. By now, much of the ice that is likely to contribute towards the ash plume has already been melted (about 10% of the glacier), so things should hopefully start to calm down a bit. But you never really know, things can change extremely fast.
According to the NOAA website, “Climate scientists and climate modelers from around the world use the Mauna Lao data to project the state of the Earth’s climate.”
That seems farcical to me but can anyone explain to me how taking measurements of carbon dioxide on top of a volcano in the middle of an ocean has anything to do with man’s emissions of CO2?
stevengoddard (09:17:35) :
Einar Kjartansson, a geophysicist at the Icelandic Meteorological Office explains what is happening :
http://www.reuters.com/article/idUSLDE63H0OV20100418?type=marketsNews
Here’s part of the problem, this guy is a geophysicist (one who studies the earth through geofantasy). The article is also from Reuters (need I say more).
…the plume of ash that is choking the upper atmosphere with tiny particles of glass and pulverised rock…
The composition of the ash is andesitic (57-58% SiO2). Andesites typically do not produce explosive eruptions. Rhyolites (>70% SiO2) typically produce explosive eruptions because of the high silica content and the high water and gas content.
This eruption is explosive (in regards to ash production because the andesitic magma is coming in contact with the glacial meltwater and pulverizing the resulting cooling magma into very tiny particles of volcanic glass called ash.
Another reason why basaltic and andesitic magmas do not produce explosive eruptions is due to the relative low viscosity of the magmas which allows the gases to escape from the magma prior to eruption. The viscosity of rhyolitic magmas is high enough to prevent the release of the gases until the magma nears the surface and the internal pressure of the gases in the magma exceeds that of that of the overlying rock at which point, the gases (and magma) break through the rock pulverizing the cooling magma and overlying rock into ash. These same super hot gases are what causes the pyroclastic flows that destroyed the forests around Mt. St. Helens.
After re-reading your post above, I guess we are basically on the same page, other than the fact that the source of the water appears to be in dispute.
http://www.tulane.edu/~sanelson/geol204/volcan&magma.htm
Henry chance (09:06:04) :
The Iranians have nothing on westerners when it comes to superstition.
http://www.washingtonpost.com/wp-dyn/content/article/2010/04/18/AR2010041802725.html
“A British friend sees this as “judgment for the bad things we have done to the Earth.” Another thinks this is the beginning of many years of volcanic activity, thus heralding the end of civilization as we know it.”
Icelandic Volcano May Be No Weather-Changing Pinatubo (Update3)
Everyone place your bets…
enneagram:
Well….i’ve read that link and it’s like an ‘Iron Sun’ ala Oliver Manuel site I think. I just don’t know enough about it but like Oliver and Tallbloke but don’t see Tallbloke here and Oliver got booted off. I do know that Leif and Scarfeta agree that there is a solar-earth connection at a low level. The problem is that the variability of the sun from very angry to spotless is @ .1K (don’t know what the ‘K’ stands for) What is missing is an input of upto 1K to driver the earth’s climatic variability. That ‘gap’ was back filled in by Gore & Co. with manure: their CO2 AGW theory, absent anything else, to explain the warming trend seen in the 80s and early 90s. Now, the sun has stopped, the temperature rise decoupled from CO2 (15 years ago). From what I can tell, Piers Corbyn & Co think that the sun drives weather and makes bet money out forecasting the met office in London. The climate however, seems to cover over solar driven weather anomalies with it’s own systems of equilibrium. I think that is what they mean when they ‘detrend’ the data they see a link but in small ways. So, The race is on to account for the ‘gap’. That’s my take on where we are.
If the electric model could answer it, it’d get a massive boost. Does it?
What are we missing about the sun, or it’s TSI, or the photon itself, that would account for this deficit?
ps. We shouldn’t steal the thread here but here is a clip from Levy Walks thread @WUWT:
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Leif Svalgaard (07:44:04) :
Nicola Scafetta (06:48:29) :
We have already proven in our subsequent papers […] We have also proved that a decadal and bidecadal temperature oscillation have solar origin.
I don’t like the proven bit. That is much too strong. And even if there is a 0.1K 11-year period [which we expect], that is such a small part of the 1K long-term trend, that one cannot claim that 60% of that is due to solar activity.
Could you comment on the ‘Science Nugget’: http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/Waiting_Times_of_Solar_Hard_X-Ray_Flares and Aschwanden’s paper.
19042010 Leif Svalgaard (08:23:45) :
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Mike Kelley (21:46:42) : My favorite definition of an expert is “some guy from out of town”.
At one point in my life (a couple of decades, actually…) I was a “consultant”; which we defined as “Someone from more than 50 miles away; with a briefcase.”…
Consultants are clearly more important than Experts, as they have a briefcase 😉
Per magma, rocks, water, etc.:
Please remember that a very many kinds of rock have chemically bound water in them (all sorts of chemical hydrates). As these are subducted, you get many kinds of chemical and physical changes. More than enough to put water INTO the volcanos in the first place. That water comes out of present day volcanoes does not say much about “where it came from” 4 billion years ago.
IMHO, it didn’t ‘come from’ anywhere. It was always here. We find it in space all over the place. It’s only the moon that’s dehydrated (and that is likely due to it being a melt artifact of planetary collisions). So the whole question of “where did the water come from” is a “Mu” question (ill formed). The real question is “Why is is liquid now?” (i.e. not chemically bound in rocks nor frozen) and that is fairly easily answered by “Solar warmth and volcanic rock decomposition”. Both, eventually, driven by nuclear energy of one end of the spectrum or the other… So we’re at a proper balance point between fusion (solar) and fission (U and Th in the planet core). That’s all…
IIRC the “us vs Volcano” CO2 number has been calculated many times and it’s “Us by a lot”. Which does not surprise me at all. We dig up far more coal and oil than volcanos do in a given year. I also don’t think it matters at all. The total carbon on the planet is a constant (modulo a few rocks falling from space and a few spacecraft launched each year). All that happens is the form changes a bit between us, trees & plants, volcanos, and rock formation / decomposition (think limestone). To think we have any significant impact is sheer hubris. The real ‘race condition’ is with plants, and they can beat us any time. Do the math… fast growing species can completely deplete ALL the CO2 in the air column above them in a single year… Measure the tons / acre of wood ( cottonwood can add 50 tons / acre of ‘wet wood’ per year…) and compare to the tons / acre of CO2 over it. I did.
http://chiefio.wordpress.com/2009/06/02/of-trees-volcanos-and-pond-scum/
i’m a consultant…..lots of money and none of the responsibility! 🙂
E Gardarsson (09:51:31) :
Here’s a pretty stunning photo of the eruption:
http://i.imgur.com/U7UY1.jpg
That photo looks like the one taken to the Chilean Chaiten Volcano eruption:
http://4.bp.blogspot.com/_SjBd7nY9Kp0/SCfJktNsxUI/AAAAAAAAAnQ/PBdoV_8D9-4/s400/Chaiten.jpg
Which is shown, also, in : http://chiefio.wordpress.com/
Quite an electrical display!
“So what is the difference between explosive and non-explosive eruptions? The difference is mainly due to the presence or absence of water. ”
That is true to some extent but another is the silica content of the magma. While water and other gases certainly do have an impact on the explosive potential, the type of magma determines how it reacts to the rapid depressurization. Magma that is silicon rich like that in the Cascades in the US erupt explosively. Magma that is silicon poor such as in Hawaii and flood basalt eruptions is more “runny” in consistency and tends to create fountains like those seen in Hawaii and early in the recent Icelandic eruption.
The current eruption in Iceland became more of an ash generator when a new vent opened that re-melted more evolved magma from a 17th century eruption that is richer in silicon (andesitic vs. basaltic). Basaltic eruptions can produce tremendous amounts of gas (including water vapor) with very little ash.
Paul Hildebrandt (10:08:34) :
Mt. St. Helens is made up of layers of andesite and basalt, yet it is known to have rather explosive eruptions from time to time.
http://en.wikipedia.org/wiki/Mount_St._Helens
The largest explosive volcanoes, like Long Valley, Valles, and Yellowstone do contain Rhyolites. The reason that they store so much energy is because they are low temperature (viscous) magmas with lots of volatiles that can’t easily escape.
I am learning quickly about volcano physiology!
I posted a comment recently that I had been told by two vulcanologists that there are two types of lava (or volcanos – not sure which since that was 40 years ago) with the Hawaiian names a’a and pahoehoe. Now we have a debate between two knowledgeable people regarding the chemical make-up of the basalt. Is it andesites vs rhyolites or just the presence of water and makes the difference?
On the water hypothesis, I question the recent posting that “This eruption is explosive (in regards to ash production) because the andesitic magma is coming in contact with the glacial meltwater and pulverizing the resulting cooling magma into very tiny particles of volcanic glass called ash.” My feeling is that the presence of ice / water outside the volcano is incidental and that the explosive nature is due only to the pressure of water and gases inside the magma. Rightly or wrongly, I picture this like the making of puffed wheat and puffed rice, in which wet wheat or rice is placed in a vessel in which the pressure and temperature are built up and then quickly released, causing steam within the wheat / rice to expand rapidly. Those of us of “a certain age” will remember Quaker Oat’s advertising that their puffed wheat was “shot from guns”. I suspect that volcanic explosions may be similar.
IanM
We don’t know where all the water in Earth’s oceans came from. Multiple sources, almost certainly, but how much from where, still much debated. And the water has been through a lot of “processing”, which makes it’s origins hard to nail down. Certainly some of it had to have been in the original accretion material, and some from infalling material of various kinds, at various times.
OT: Current sunspot number=0
Not OT: The Chilean city of Concepcion moved three meters to the west after the earthquake of magnitude 8.8 on the Richter scale that struck Feb. 27 central and southern Chile, according to a study released today by the University of Santiago
http://www.latercera.com/contenido/739_252611_9.shtml
The rise in CO2 levels was predictable: CO2 lags temperature by around 800 years….it’s been that long since the MWP.
Just a head’s up that there is a really interesting to and fro on Dr. Pielke’s Sr. blog between him, Dr. Trenberth and Dr. Willis.
Such as – “….You should also note that Karina’s paper suffered from errors in the altimeter data that were still not corrected at the time of her paper. These errors tended to make the altimeter time series show too much global sea level rise, and after correcting them the trend in globally averaged sea level since 2004 or 2005 is significanly lower.
Finally, I do not think that any of the techniques used by various groups should be supressing the global warming signal in the data over the period from 2005 to the present. As I mentioned above, the Argo data coverage during this period is such that any reasonable interpolation technique should do. Capturing the trend over 50 years, however, is another story.
Cheers,
Josh”
http://pielkeclimatesci.wordpress.com/2010/04/19/further-feedback-from-kevin-trenberth-and-feedback-from-josh-willis-on-the-ucar-press-release/
Simplicio (10:00:03) writes:
According to the NOAA website, “Climate scientists and climate modelers from around the world use the Mauna Lao data to project the state of the Earth’s climate.”
That seems farcical to me but can anyone explain to me how taking measurements of carbon dioxide on top of a volcano in the middle of an ocean has anything to do with man’s emissions of CO2?
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It produces the desired result.
” E.M.Smith (11:40:17) :
[…]
http://chiefio.wordpress.com/2009/06/02/of-trees-volcanos-and-pond-scum/
”
ChiefIO, interesting essay, but one word re the “one generation short of CO2 depletion”: Lack of CO2 would cause a plant die-back and release some CO2 again; a forest fire would do the same, rotting trees do the same so the game of life can always continue – albeit on a nearly depleted atmospheric level of CO2 – always just short of starvation if you will…
Ian L. McQueen (12:18:46) :
a’a and pahoehoe are both types of basalt.
The larger categories are Basalt, Ryholite and Andesite – which is essentially a mixture of Basalt and Granite. The difference between Ryholite and Granite is that Ryholite made it to the surface before cooling.
crosspatch (11:58:50) :
The reason that high silica magmas can be explosive is because they contain a lot of water. The compressibility of liquids and solids is much to low to store the energy required to create a large explosion.
Hawaiian basalts are not explosive because they don’t come into contact with much water, unless the lava flow pours into the sea.
PDF document on Concepcion city movement to the west:
http://www.usachaldia.cl/images/stories/pdf/terremoto-chile.pdf
“70% of the earth’s surface is covered with water. Where did that water come from? ”
The “Water Fairy”, you dolt! Didn’t your mother teach you ANYTHING?
FOR
Walter M. Clark (20:33:36):
And there was evening and morning the first day…
The old Hebrew words for morning and evening were the same agricultural words for opening a furrow to plant (morning) and closing the furrow (evening). So the words evening and morning can be argued to mean God’s starting the “planting” and finishing it.
Also, the word to create, in Old Hebrew “barah” means to create from nothing. God “barahed” the heavens and the earth. the Bible uses the O.H. “asah” for the days of creation meaning to create, as a sculptor from clay, from some material already present.
“There are various types of volcanoes. Let’s remember the story of Pompeii, for instance, where the entire city was buried under streams of lava. But Icelandic volcanoes are unique, and their eruptions are completely different,” Fyodorov explained.
“These volcanoes are dry, because ashes ejections are dehydrated to 0.5% unlike, for instance, Indonesia volcanoes with the level of humidity at 8%. Since dry volcanoes emit small amount of haloid acids (HCl; HBr), chances of acid rains after the eruption are very slim. However, ejected ashes may form a “hot cloud” which is a mixture of ashes, gas and water steam that transform into a heavy vapor suspended matter and blanket flatlands.
http://english.pravda.ru/hotspots/disasters/19-04-2010/113073-volcano-0
People who doubt that water is the cause of explosive volcanic eruptions should ask themselves “what is it that causes explosions?”
The main types of explosions are
1. Explosions caused by release of energy from chemical reactions. Not much of that going on in volcanoes.
2. Explosions caused by release of energy from nuclear reactions. Not much of that going on in volcanoes.
3. Explosions caused by conversion of thermal energy to mechanical energy, normally using steam as the transfer agent. Happens often in volcanoes.
4. Explosions caused by compressed gases (like water vapor) being released. Happens when dissolved gases in magma reach the surface.
All of the previous eruptions were precursors to more massive activity from the neighbouring Katla volcano, which this time, according to geologists, could take one to two years to erupt. And Eyjafjallajökull is the dwarf, Katla the giant.
http://english.pravda.ru/world/europe/17-04-2010/113070-iceland_volcano-0
Hoorah! Mechanical engineering comes to the rescue with a simple explanation on volcanic eruptions!
And for all the techno-geeks out there, remember this: with the exception of the miniscule contribution of wind, solar, biomass, etc., all significant electric generation, whether nuclear or fossil, starts out as steam driving a turbine which is coupled to a generator. The only difference is: nuclear derived steam is for the most part saturated; fossil derived steam is invariably superheated, more efficient and packs more of a punch per pound.
Increasing activity at the Katla volcano, live data:
http://hraun.vedur.is/ja/Katla2009/stodvaplott.html
“DirkH (13:02:22) :
[…]
of life can always continue – albeit on a nearly depleted atmospheric level of CO2 – always just short of starvation if you will…”
One more thought on this:
When CO2 depletion sets in, we will see plant die-back. Where will we see it? In the places where it’s hard for plants to survive, so deserts start to grow in the +-30 degree latitude range because of the Hadley cells. The available carbon doesn’t suffice to cover the entire available landmass area with plants, so some places turn into deserts.
So the Sahara and all the other great deserts are caused by a combination of CO2 and H2O scarcity.
stevengoddard (12:05:04) :
Mt. St. Helens is made up of layers of andesite and basalt, yet it is known to have rather explosive eruptions from time to time.
All the Plinian eruptions (explosive) are dacitic magmas (see 3rd link below). Dacite has the same relative percentage of silica that rhyolite does but tends to contain more calcium-rich feldspar (plagioclase versus potassium feldspars).
http://en.wikipedia.org/wiki/File:Dacite-AphaniticQAPF.gif
http://www.geology.sdsu.edu/how_volcanoes_work/Controls.html
http://geology.geoscienceworld.org/cgi/content/abstract/23/6/523
The largest explosive volcanoes, like Long Valley, Valles, and Yellowstone do contain Rhyolites. The reason that they store so much energy is because they are low temperature (viscous) magmas with lots of volatiles that can’t easily escape.
Again, the reason why the volatiles can’t escape is because of the high silica content. High silica means sticky lava/magma. Low silica means fluid lava/magma (hence, the volatiles escape early on before the magma gets any way near the surface).
The ash from the Icelandic volcano is andesitic in composition and is not normally erupt in a Plinian style.
stevengoddard (13:39:30) :
People who doubt that water is the cause of explosive volcanic eruptions should ask themselves “what is it that causes explosions?”
The main types of explosions are
1. Explosions caused by release of energy from chemical reactions. Not much of that going on in volcanoes.
2. Explosions caused by release of energy from nuclear reactions. Not much of that going on in volcanoes.
3. Explosions caused by conversion of thermal energy to mechanical energy, normally using steam as the transfer agent. Happens often in volcanoes.
4. Explosions caused by compressed gases (like water vapor) being released. Happens when dissolved gases in magma reach the surface.
I agree.
Wasn’t Spock a Vulcanologist?
For anybody doubting Steve, check this out, it gets real interesting about 4 1/2 minutes in.
johnythelowery (05:41:03)
Well said. But I don’t see that the flood covering the highest mountain is an issue if it occurred at the start of the supercontinent breakup. The highest mountains we know today (on earth) are caused by the tectonic plates colliding. So if the flood heralded the start of the breakup (hot water under pressure coming up from deep fissures – ‘the fountains of the deep’) – then present day highest mountains obviously couldn’t have formed yet. If it’s given that the supercontinent was flatter than our present day land masses, then covering the super continent in water doesn’t take as much water as one might initially surmise, as the highest mountain back then may have been like a hill in comparison.
Joe (05:01:11) :
I wonder if earth’s unexplained increases in orbit (somewhere around 10m/cy) could also be contributing to volcanic activity. I was hoping it might provide a mechanism for the expanding earth theory, but I may be hoping for too much there.
Matt B (18:29:40) :
Thank you. It’s a tough one really, frankly, the Noah story. Mt. Ararat and all that. I’m definately not a young earth guy but better get off this. Another time maybe.
Paul Hildebrandt (15:13:20) :
You said “High silica means sticky lava/magma. Low silica means fluid lava/magma (hence, the volatiles escape early on before the magma gets any way near the surface).”
This is true, but the reason why high silica magmas are viscous is because they melt at lower temperatures, and because they contain a lot of volatiles. It is the volatile gases which create the explosions, not the quartz/potassium feldspar content.
RE: johnythelowery (05:50:15) : “Maybe nitpicking, but let’s remember: clouds don’t consist of water vapour. It is water. Aerosol”
This is primarily why I do not like the term ‘water vapor.’ In common parlance, a ‘vapor’ is an aerosol. In most cases here, especially with regard to greenhouse (earthshine resonant) gases, the term ‘water vapor’ is used to indicate ‘clear air water content.’ I am not sure that this distinction is well understood by the general public.
Steve Schaper (23:52:26) :
“evening and morning”
again, translation problem
it does not say “night and day”
“evening and morning”, same as “ending and beginning”, or “dusking and dawning”, i.e., ending, dusking of one eon or era, beginning, dawning of a new one
Darkinbad the Brightdayler (00:19:01) :
A couple of glasses of Brennevin (Black Death) and all will become clear in the following joke from an Icelandic friend:
The economy has died, been cremated and its ashes are being scattered all over Europe.
…………………………………………………………………………………………………………..
Europe, from whence its economic problems came. But then Icelandic banks shouldn’t have been greedy and made themselves an offshore haven for European money.
KeithGuy (02:15:53) :
I heard an interesting take on the disruption of the Icelandic volcano on BBC radio today. It said:
“Good news for the carbon budget with all of those grounded planes.”
Eh?
I wonder what they think comes out of volcanoes?
………………………………………………………………………………………………………………
Ya, boy, they’re thinking.
Ian L. McQueen (12:18:46) :
On the water hypothesis, I question the recent posting that “This eruption is explosive (in regards to ash production) because the andesitic magma is coming in contact with the glacial meltwater and pulverizing the resulting cooling magma into very tiny particles of volcanic glass called ash.” My feeling is that the presence of ice / water outside the volcano is incidental and that the explosive nature is due only to the pressure of water and gases inside the magma.
What makes you think that the andesitic magma has enough water and other gases in it to cause a Plinian eruption?
A small quibble here, but according to Webster’s one definition of smoke is:
A suspension of particles in a gas
By this definition, the caption describing the cloud as smoke and ash is absolutely correct. Sure, we most often think of smoke as a combustion phenomena, but that’s not necessarily the only definition, just as we usually consider ash to be the carbonized remains of combustion, but of course volcanic ash is something else entirely.
Finally, pretty much all smoke, whether from combustion or otherwise consists largely of water vapour (in this case by vapour, I mean the mixture of steam and liquid aerosol particulates).
stevengoddard (19:40:58) :
This is true, but the reason why high silica magmas are viscous is because they melt at lower temperatures, and because they contain a lot of volatiles. It is the volatile gases which create the explosions, not the quartz/potassium feldspar content.
Ok, I’ll give you partial credit. However, please read the following (which is what I have been trying to impress upon you from the beginning):
Viscosity of Magmas
Viscosity is the resistance to flow (opposite of fluidity). Viscosity depends on primarily on the composition of the magma, and temperature.
* Higher SiO2 (silica) content magmas have higher viscosity than lower SiO2 content magmas (viscosity increases with increasing SiO2 concentration in the magma).
* Lower temperature magmas have higher viscosity than higher temperature magmas (viscosity decreases with increasing temperature of the magma). (I’ll give you partial credit here.)
Thus, basaltic magmas tend to be fairly fluid (low viscosity), but their viscosity is still 10,000 to 100,0000 times more viscous than water. Rhyolitic magmas tend to have even higher viscosity, ranging between 1 million and 100 million times more viscous than water. (Note that solids, even though they appear solid have a viscosity, but it very high, measured as trillions time the viscosity of water). Viscosity is an important property in determining the eruptive behavior of magmas.
Volcanic Eruptions
* In general, magmas that are generated deep within the Earth begin to rise because they are less dense than the surrounding solid rocks.
*
As they rise they may encounter a depth or pressure where the dissolved gas no longer can be held in solution in the magma, and the gas begins to form a separate phase (i.e. it makes bubbles just like in a bottle of carbonated beverage when the pressure is reduced).
*
When a gas bubble forms, it will also continue to grow in size as pressure is reduced and more of the gas comes out of solution. In other words, the gas bubbles begin to expand.
*
If the liquid part of the magma has a low viscosity, then the gas can expand relatively easily. When the magma reaches the Earth’s surface, the gas bubble will simply burst, the gas will easily expand to atmospheric pressure, and a non-explosive eruption will occur, usually as a lava flow (Lava is the name we give to a magma when it on the surface of the Earth).
*
If the liquid part of the magma has a high viscosity, then the gas will not be able to expand very easily, and thus, pressure will build up inside of the gas bubble(s). When this magma reaches the surface, the gas bubbles will have a high pressure inside, which will cause them to burst explosively on reaching atmospheric pressure. This will cause an explosive volcanic eruption.
Anyway, hit the wrong button. Wasn’t quite finished.
Gas does play a minor part in the viscosity of the magma. Let me repeat that, MINOR. Silica content is the main player. Here is the link to the article: Actually, it’s Geology 204 at Tulane.
http://www.tulane.edu/~sanelson/geol204/volcan&magma.htm
Here’s a better description from another source:
http://www.geology.sdsu.edu/how_volcanoes_work/Controls.html
MAGMA VISCOSITY, TEMPERATURE, AND GAS CONTENT
The viscosity of a substance is a measure of its consistency. Viscosity is defined as the ability of a substance to resist flow. In a sense, viscosity is the inverse of fluidity. Cold molasses, for example, has a higher viscosity than water because it is less fluid. A magma’s viscosity is largely controlled by its temperature, composition, and gas content. The effect of temperature on viscosity is intuitive. Like most liquids, the higher the temperature, the more fluid a substance becomes, thus lowering its viscosity.
Composition plays an even greater role in determining a magma’s viscosity. A magma’s resistance to flow is a function of its “internal friction” derived from the generation of chemical bonds within the liquid. Chemical bonds are created between negatively charged and positively charged ions (anions and cations, respectively). Of the ten most abundant elements found in magmas (see above), oxygen is the only anion. Silicon, on the other hand, is the most abundant cation. Thus, the Si-O bond is the single most important factor in determining the degree of a magma’s viscosity. These two elements bond together to form “floating radicals” in the magma, while it is still in its liquid state (i.e., Si-O bonds begin to form well above the crystallization temperature of magma). These floating radicals contain a small silicon atom surrounded by four larger oxygen atoms (SiO4). This atomic configuration is in the shape of a tetrahedron. The radicals are therefore called silicon-oxygen tetrahedra, as shown here.
These floating tetrahedra are electrically charged compounds. As such, they they are electrically attracted to other Si-O tetrahedra. The outer oxygen atoms in each tetrahedron can share electrons with the outer oxygen atoms of other tetrahedra. The sharing of electrons in this manner results in the development of covalent bonds between tetrahedra. In this way Si-O tetrahedra can link together to form a variety shapes: double tetrahedra (shown here, C), chains of tetrahedra, double chains of tetrahedra, and complicated networks of tetrahedra. As the magma cools, more and more bonds are created, which eventually leads to the development of crystals within the liquid medium. Thus, the Si-O tetrahedra form the building blocks to the common silicate minerals found in all igneous rocks. However, while still in the liquid state, the bonding of tetrahedra results in the polymerization of the liquid, which increases the “internal friction” of the magma, so that it more readily resists flow. Magmas that have a high silica content will therefore exhibit greater degrees of polymerization, and have higher viscosities, than those with low-silica contents.
The amount of dissolved gases in the magma can also affect it’s viscosity, but in a more ambiguous way than temperature and silica content. When gases begin to escape (exsolve) from the magma, the effect of gas bubbles on the bulk viscosity is variable. Although the growing gas bubbles will exhibit low viscosity, the viscosity of the residual liquid will increase as gas escapes. The overall bulk viscosity of the bubble-liquid mixture depends on both the size and distribution of the bubbles. Although gas bubbles do have an effect on the viscosity, the more important role of these exsolving volatiles is that they provide the driving force for the eruption.
Hopefully, this will help clear thing up for you.
There are some VERY cool photos of volcanic lightning posted on this site, check ’em out!
http://www.spaceweather.com/
Oh yeah, “the sun is blank, no sunspots.”
Hot off the press – Quake hits Kalgoorlie, Western Australia
The quake struck with a magnitude of 4.8 at 8.17am (WST) on Tuesday, Geoscience Australia said.
This is the largest event in the last 25 years in this region and it might be the largest since we started recording
From http://au.news.yahoo.com/a/-/latest/7084400/quake-hits-kalgoorlie-damages-buildings/
Paul Hildebrandt (20:13:17) : [Surface Water Driven Volcanic Explosions]
My take on this is that a truly explosive eruption requires confinement of the water in contact with magma so that pressure can build up to the surface-rupture point. If you have a mechanism that allows surface water to leak into the magma stream and subsequently be confined long enough to allow explosively high pressures to develop then I would agree that this is possible. I note that the undersea volcanoes near Hawaii have not produced any grand explosive eruptions.
I suspect that water entrained in marine rocks subducted from the sea floor might produce a much more explosive emerging magma than similar material subducted from a dry environment.
The late Professor Lance Endersbee, Emeritus Professor; former Dean of Engineering and Pro-Vice Chancellor of Monash University claimed that water was created internally.
Endersbee’s main focus was on the state of the world’s groundwater, the rapid consumption of which has put the world on the edge of a little understood catastrophe because contrary to popular belief groundwater reserves are not replenished from the surface.
http://www.abc.net.au/rn/latenightlive/stories/2006/1808528.htm
http://mpegmedia.abc.net.au/rn/podcast/2006/12/lnl_20061211.mp3
Spector (21:42:48) :
If you put a bullet in a fire, it will make a loud bang. If you put a bullet in a gun in a fire, it can be lethal. The explosion which sends the bullet flying at high speed is created by the confinement inside the steel barrel and chamber of the gun.
Don’t try either experiment at home.
BTW – if you took a .223 rifle to the moon and pointed it straight up in the “air,” the bullet would travel well over 50 miles upwards before it started to fall.
Paul Hildebrandt (20:32:18) :
If you heated up a high silica magma to 1200C (basalt temperature) it would lose most of it’s viscosity and volatiles.
Again, the reason why high silica magmas are viscous is because the eutectic melt with quartz, feldspar and water happens at a low temperature. Low temperature means more viscous. (You can’t have molten basalt at 800C) This allows it to retain volatiles which increase the viscosity further.
It is the presence of the volatile gases, like water, which makes high silica magma often explosive.
If you think carefully about what I am saying, it is consistent with the references you are providing. I am just adding a further dimension explaining what makes those lavas potentially explosive.
Iceland is a “hot spot”? I thought it was a mid ocean spreading ridge exposed above the surface.
See: http://vulcan.wr.usgs.gov/Glossary/PlateTectonics/description_plate_tectonics.html
Not that the two are mutually exclusive, I suppose . . . .
Mike Fox (22:55:37)
Iceland is definitely a hot spot. Do you see other similar places along the mid-Atlantic ridge?
“When there’s the right ratio of water to magma, volcanoes can have what are known as phreatomagmatic eruptions, where the water flash-steams, creating a huge plume of ash and steam. “Once the interaction with the (water in the) glacier stops, you go into dry mode,” says Shanaka deSilva, a professor of geoscience at Oregon State University in Corvallis.”
http://www.usatoday.com/tech/science/2010-04-19-volcano-eruption-lava_N.htm
RE: stevengoddard (23:21:42) : [Phreatomagmatic Eruptions]
Steve:
I assume this applies to the case where the volcano is already exploding with such violence that the overburden of ice is quickly boiled or melted away on direct contact with the expanding plume of erupting material. I suspect that a major eruption at the Crater Lake Volcano could vaporize the whole lake in short order.
Matt B (18:29:40) :
Orbit does not effect the build-up of pressure under the planet surface. Orbit is the mechanics of rotating and the enegy infused at the time of creation is slowly being used up. All planets orbits are slowly moving away from the sun and the suns corona explading slowly is the slowing of rotation.
Spector (21:42:48) :
I note that the undersea volcanoes near Hawaii have not produced any grand explosive eruptions.
Of course, it does have 3,000 or so meters of water over top of it. Here’s a video of one coming near the surface:
It seems to be rather violent.
Spector (21:42:48) :
I suspect that water entrained in marine rocks subducted from the sea floor might produce a much more explosive emerging magma than similar material subducted from a dry environment.
That water does not necessarily stay with those rocks. The water tends to be forced out into the overlying rock and helps with the partial melting of the overlying rock. This water is then incorporated into the magma. Depending on the degree of melting and the temperatures reached, the water either is incorporated into the mineralogy (plutonic rocks); is exsolved on the way up (basaltic to andesitic volcanics); or remains in the magma to help produce the explosive volcanics (andesitic to rhyolitic). If the dacitic to rhyolitc magma doesn’t quite make it to the surface, the gases (along with the other incompatible elements) are driven off as the magma body cools and crystallizes. As these gases and other elements cool on their way away from the plume, the elements eventually precipitate out forming those fantastic mineral deposits containing everything from molybdenum to silver and gold. Sometimes that water doesn’t quite make it to the surface.
Spector (21:42:48) :
I suspect that water entrained in marine rocks subducted from the sea floor might produce a much more explosive emerging magma than similar material subducted from a dry environment.
Forgot to ask, where would you find a dry subduction zone?
E.M.Smith (11:40:17) :
[…]
http://chiefio.wordpress.com/2009/06/02/of-trees-volcanos-and-pond-scum/
My botany is a bit rusty but as I recall, during the day while photosynthesis is the dominant process in leaves, carbon dioxide is taken up from the air and used in the process of making sugars. At night, when photosynthesis does not occur – no sunlight for energy – respiration occurs, which gives off carbon dioxide just as it does in animals.
Is this nighttime respiration from plants figured in to your CO2 calculations? Are your calculations “net” CO2 being scrubbed by plants?
janama (21:52:47) :
The late Professor Lance Endersbee, Emeritus Professor; former Dean of Engineering and Pro-Vice Chancellor of Monash University claimed that water was created internally.
Endersbee’s main focus was on the state of the world’s groundwater, the rapid consumption of which has put the world on the edge of a little understood catastrophe because contrary to popular belief groundwater reserves are not replenished from the surface.
http://www.abc.net.au/rn/latenightlive/stories/2006/1808528.htm
http://mpegmedia.abc.net.au/rn/podcast/2006/12/lnl_20061211.mp3
———————————————————-
There is a massive under ground reservoir lake in the American Mid-West
called, I think, the Magellan…, which due to high water extraction for farming
in Nebraska, Etc. is running dangerously low. That was from a National Geographic a few years ago. With the flooding out there, has this
Under ground reservoir returned to normal? Without replenishment, it’ll conk out in our life times and end the mid-west farming. it stretches from the Canadian border (?) to New Mexico(?). Anyone know anything about this issue and can provide an update??
You’re assuming the surface of the Earth became molten, that at one time all of Earth was molten, and that magma can’t contain water. The first two are difficult to prove, while it is known that there is water in magma and it is important to magma characteristics and chemistry. Also, even if early Earth was molten early on, was it in that condition when the Mars-sized impactor created the Moon — and was the impactor fully molten? That impact would have provided a lot of new material. There also is evidence that the resulting rock atmosphere may have lasted only a few hundred years because there was an ocean on Earth shortly after the Moon was created. There’s been a lot of water around.
Much of earth’s water is tied up in rocks. Almost all minerals are hydrates, with some rocks holding H2O as a clathrate, or complex, with as many as twenty molecules of water per molecule of dry mineral.
When rocks are heated, even moon or Martian rocks, they give off water. Also, water is subducted into the mantle at plates, and if they are in or adjacent to the sea, this material contains lots of free water as well.
RE: Paul Hildebrandt (06:07:02) : “Forgot to ask, where would you find a dry subduction zone?”
I think these may be found in places where continents from two different plates have come together forming a huge mountain chains such as under the Alps or Himalayas.
BTW, I believe the Cascadian volcanoes in the Pacific Northwest are thought to be the result of a stream of marine material from the Juan de Fuca Plate that is being subducted under the North American Plate.
Spector (14:32:56) :
I think these may be found in places where continents from two different plates have come together forming a huge mountain chains such as under the Alps or Himalayas.
No subduction there. Hence, the great height of the Himalayas. In fact, they are still going up. Also, try to find volcanoes in the Himalayas. Let me know if you find any.
BTW, I believe the Cascadian volcanoes in the Pacific Northwest are thought to be the result of a stream of marine material from the Juan de Fuca Plate that is being subducted under the North American Plate.
Correct.
johnythelowery (10:32:14) :
There is a massive under ground reservoir lake in the American Mid-West
called, I think, the Magellan…, which due to high water extraction for farming
in Nebraska, Etc. is running dangerously low. That was from a National Geographic a few years ago. With the flooding out there, has this under ground reservoir returned to normal? Without replenishment, it’ll conk out in our life times and end the mid-west farming. it stretches from the Canadian border (?) to New Mexico(?). Anyone know anything about this issue and can provide an update??
It’s called the Ogallala Aquifer. It was a problem back in the 80’s when I lived along the Front Range, Colorado.
http://www.waterencyclopedia.com/Oc-Po/Ogallala-Aquifer.html
http://www.iitap.iastate.edu/gccourse/issues/society/ogallala/ogallala.html
http://www.npwd.org/Ogallala.htm
http://www.washingtonpost.com/wp-dyn/content/article/2010/04/20/AR2010042005301.html?hpid=topnews
RE: Paul Hildebrandt (19:43:31) : [Himalayan Subduction Zone] No subduction there. Hence, the great height of the Himalayas. In fact, they are still going up. Also, try to find volcanoes in the Himalayas. Let me know if you find any.
This may depend on how you define ‘subduction zone.’ I believe there must be a zone of descending magma underneath these mountains that is pulling the continents together. This subduction process may be occurring at such depths that the subducted material can only come near the surface again after a complete convection cycle when it might rise again under a line of active sea-floor spreading.
Spector (06:43:39) :
This may depend on how you define ’subduction zone.’ I believe there must be a zone of descending magma underneath these mountains that is pulling the continents together. This subduction process may be occurring at such depths that the subducted material can only come near the surface again after a complete convection cycle when it might rise again under a line of active sea-floor spreading.
Let’s try this one, even though it’s from a wiki:
Definitions of Subduction zone on the Web:
* In geology, subduction is the process that takes place at convergent boundaries by which one tectonic plate moves under another tectonic plate, sinking into the Earth’s mantle, as the plates converge. …
en.wikipedia.org/wiki/Subduction_zone
My definition, above, says that one tectonic plate has to override another tectonic plate resulting in the subduction of the overridden plate into the mantle. Even if the subducted material is incorporated into the mantle, most of the water and/or volatiles will be driven off due to the high temperatures and pressures. Even if continental crust is subducted, the crust is too dry to initiate melting in the overriding crust. Hence, the lack of volcanics.
RE: Paul Hildebrandt (10:06:41) :
Ref: USGS site document entitled “Understanding Plate Motions”
http://pubs.usgs.gov/gip/dynamic/understanding.html
At this site I note that there is a diagram that appears to show the lithosphere of the Indian Plate being subducted under the Eurasian plate and dropping into the asthenosphere without producing any volcanic activity. When this subduction stops pulling the two land-masses together, I assume the Himalayan mountain building will also stop. This appears to be a classic example of one of the three types of convergent plate boundaries.
Another type of convergent plate boundary is the deep trench that forms at the convergence of two oceanic plates. I presume that material subducted there would be more likely to pull water and carbon compounds down into the interior of the earth.
Iceland, BTW, appears to be located on a divergent plate boundary.
Spector (14:51:26) :
At this site I note that there is a diagram that appears to show the lithosphere of the Indian Plate being subducted under the Eurasian plate and dropping into the asthenosphere without producing any volcanic activity. When this subduction stops pulling the two land-masses together, I assume the Himalayan mountain building will also stop. This appears to be a classic example of one of the three types of convergent plate boundaries.
I stand corrected on the subduction of continental crust. However, only thin slices of it actually get subducted. The majority of the crust is scraped off and piled up against the overriding plate. This brings us back to the original statement you made. Here it is below for your convenience.
Spector (21:42:48) :
Paul Hildebrandt (20:13:17) : [Surface Water Driven Volcanic Explosions]
I suspect that water entrained in marine rocks subducted from the sea floor might produce a much more explosive emerging magma than similar material subducted from a dry environment.
You state that magma from a dry subduction zone would produce less energetic eruptions than from a wet subduction zone. I’m not sure if any melting takes place except at extreme depths due to the absence of sufficient quantities of water. What little magma that is produced most likely never even comes close to the surface and therefore crystallizes over the millenia forming a pluton, stock, or sill.
Iceland, BTW, appears to be located on a divergent plate boundary.
Correct. There is some speculation in some circles that Iceland may have been the impact point of a meteor on a spreading center, thus the island and copious volcanic activity.
RE: Paul Hildebrandt (16:04:52) :
On reflection, I probably should have said that the overall dissolved gas content of the rising magma contributes to the rate or frequency of volcanic activity at any given site. This gas content, including water, probably depends on the overall history of the rising magma at each location.
I think the explosivity of these eruptions is primarily determined by the typical strength of the confinement structure that forms after each eruption to block the continued flow of magma. This strength would determine how high the magma pressure must increase to once more rupture the structure. I assume this blockage may contain cracks allowing some gas but not magma penetration as long as it remains in a general state of compression. I believe that strong confinement structures produce less frequent, but more violent eruptions.
I am not sure whether ice-loading on a volcano acts to delay eruptions by offsetting the pressure building up from below or if it might cause top-heavy torsional stresses that would weaken the magma confinement.
I note that the following site from the Department of Geological Sciences, San Diego State University entitled “How Volcanoes Work” seems to contain a lot of useful information:
http://www.geology.sdsu.edu/how_volcanoes_work/
“”” Paul Hildebrandt (06:07:02) :
Spector (21:42:48) :
I suspect that water entrained in marine rocks subducted from the sea floor might produce a much more explosive emerging magma than similar material subducted from a dry environment.
Forgot to ask, where would you find a dry subduction zone? “””
Isn’t India the Poster Child for that ? Supposedly it is still pushing northwards, and driving the Himalayas to new heights.
George E. Smith (10:38:34) :
Forgot to ask, where would you find a dry subduction zone? “””
Isn’t India the Poster Child for that ? Supposedly it is still pushing northwards, and driving the Himalayas to new heights.
It’s more of oceanic crust/continental crust subduction zone, followed by crustal collision with the mantle breaking off and the “subducted” crust underplating the overriding crust as can be seen in Figures 26 and 27 of this link:
http://www.geo.arizona.edu/~ozacar/models~1.htm