Hot Water, Hot Earth 236
Calopteryx notes a New Scientist article on the discovery of "supercritical" water emerging from a vent in the Atlantic Ocean at 407 deg. C (765 deg. F). One of its discoverers actually said, "It's water, but not as we know it"; it's the hottest water ever found on earth. The cause seems to be a huge bubble of magma beneath the ocean floor, 3 km below the sea surface. Meanwhile Nymz shares a journal entry on a hot spot on land: a 2-acre patch in Ventura county, in California, that has heated up to 433 deg. C (812 deg. F). Here geologists blame buried hydrocarbons burning as they get access to air through cracks in the ground. That high temperature was measured a foot below the ground surface.
Does this seem a bit obvious to anyone (Score:5, Informative)
As heat increases, density decreases due to increased movement of the particles.
Therefore, shouldn't water at the bottom of the ocean have an unusually high boiling point - and water which is heated to near that boiling point be much less dense?
To me it seems like they're backing up existing thermodynamic properties with evidence
Supercritical water oxidation (Score:5, Informative)
Once you put water under enough pressure (think 4000 PSI), you can pump almost an infite amount of heat into it without it undergoing a phase change. [wikipedia.org] Useful for all sorts things, like breaking down any organic compound into constituant atoms. So the water in the story isn't the hottest on earth, only the hottest naturally occuring.
Re:Can we still blame pollution for this? (Score:3, Informative)
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Seriously, though, wouldn't the water just convert to steam at that point, even if it WAS under that much water?
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Not under that amount of pressure.
Re:Can we still blame pollution for this? (Score:5, Informative)
The term "supercritical" doesn't just make a nice-sounding buzzword to toss into the article.
It literally means that you can make no meaningful distinction between the liquid and gaseous phases of the water at that pressure and temperature - You have something between the two phases with no phase-change energy transition separating them.
As an aside, humans use supercritical water all the time, in power plants. This only counts as interesting because we've never seen it occur naturally before (most likely because we don't tend to hang out a lot in places at pressures above 22MPa).
Re:Does this seem a bit obvious to anyone (Score:4, Informative)
Re:The Year Was 1977 ... (Score:5, Informative)
Re:Can we still blame pollution for this? (Score:5, Informative)
Actually there is a reason: it's "supercritical".
For it to turn to steam would require a phase change between it and the surrounding water, and a supercritical fluid by definition has no distinct phase change between the liquid and gasous phases.
You'd think that if the pressure would be high enough, a liquid would stay a liquid at any arbitrary temperature, but that's not what happens. If you have a vessel strong enough to withstand the increasing pressure, and you heat a liquid within it, that has a gasous phase above it, you first see boiling. Then, as the pressure in the gas phase rises, the boiling stops. But, if you keep heating it, an interesting thing happens: the line between liquid and gas phase disappears, and the fluid only has one phase. It is supercritical.
In this case, boiling never starts because the pressure is high to begin with.
Now, the supercritical water is much less dense than seawater (or plain water, for that matter), so it does rise, and if it cools slower than the pressure drops as it rises, yes, it might start to boil.
Re:Does this seem a bit obvious to anyone (Score:2, Informative)
Pressure at 3000m is about 290 atmospheres.
Absent Temperture Scale (Score:5, Informative)
Ground temperatures exceeding 800 degrees (C? F? HOT!) are being recorded [latimes.com] at the Los Padres Forest in Ventura County, California. Geologists are uncertain why, but a popular theory is that hydrocarbons in some form (petroleum, gas, coal) are being exposed to air through cracks formed in dry ground. (Fuel + Oxygen + Heat = Fire Triangle) [wikipedia.org] The last thing California needs are forest fires from below, after so recently fighting off forest fires from lightning above, [ca.gov] so fire fighters are closely monitoring the area.
Re:Start drillin'! (Score:5, Informative)
Yeah, that's how they still put out oil well fires. However, if you ever seen oil "gushing" these days, that's a huge, huge problem. That stuff only happened back pre-1950's or so when they use "spudders" to drill without significant drilling fluid. These days, using rotary drilling, such heavy "mud" is used while drilling that blow-outs should never occur, as they can obviously be ridiculously dangerous.
I, personally, can't wait for Al Gore to propose a new tax because the earth is burning its own petroleum without any heed to environmental impact. SHAAAAAAAAAAAME, SHAAAAAAAME!
J
Re:Start drillin'! (Score:5, Informative)
Dousing with copious amounts of water
Raising the plume- Inserting one metal casing 30 to 40 feet high over the well head (thus raising the flame above the ground). Liquid nitrogen or water is then forced in at the bottom to reduce the oxygen supply and put out the fire.
Drill relief wells to redirect the oil and make the fire smaller (and easier to extinguish with water).
Using a jet engine to direct high pressure water and air over the well.
Using dynamite to 'blow out' the fire by blasting fuel and oxygen from the flame and consuming oxygen in the combustion. This was one of the earliest effective methods and is still widely used. The first use was by Myron Kinley's father in California in 1913
Dry Chemical (mainly Purple K) can be used on small well fires such as those in refineries.
The above was stolen from wikipedia (duh!) and there is actually a page for oil well fires:
http://en.wikipedia.org/wiki/Oil_well_fire [wikipedia.org]
Re:Burning Hydrocarbons (Score:5, Informative)
This isn't the town that had to be condemned because the coal underground was ignited?
That would be Centralia, Pennsylvania [wikipedia.org]
Re:Start drillin'! (Score:3, Informative)
The area in Ventura County where this is happening is pretty close to where there are already quite a few oil pumps. A large chunk of the land alongside the highway going from Ventura toward Fillmore (the hotspot is North of Fillmore) is owned by some oil company.
The offramps indicate that it's Shell, but it may have changed hands since the roads were named.
My point is that some oil company already has a pretty strong presence in the area, so maybe it wouldn't be as difficult as you think. On the other hand, it sounds like the area is inside the Los Padres National Forest, so it may well be untouchable.
Re:Burning Hydrocarbons (Score:3, Informative)
This isn't the town that had to be condemned because the coal underground was ignited?
That would be Centralia, Pennsylvania [wikipedia.org]
And that's not the only underground coal fire [wikipedia.org].
Re:When will people learn?!?!?! (Score:1, Informative)
Perhaps I should explain. If I put a 100 pound weight on one side of scale and 100 pounds of gold on the other the scale should stay balanced right? I mean assuming this is scale is working like a scale should. Now suppose I put just one ounce of gold extra on the scale. It's just one ounce of gold right? Compared to the 100 pounds that's like a shaving. Shouldn't make much difference, but now the scale's off balance.
Actually, your choice of gold is rather amusing, since 100 pounds of gold = 100 Troy pounds, while 100 pound weight generally means avoirdupois pounds (which are heavier). On the other hand, troy *ounces* are heavier than avoirdupois -- the flip is because troy pounds are 12 troy ounces, whereas avoirdupois pounds are 16 avoirdupois ounces.
So, in fact, the scales started off out of balance and the addition moved them a bit closer to proper balance. (You need ~257.3 more ounces of gold to get there.)
[/pedantry]
Re:Video of Triple Point (Score:3, Informative)
The CO2 triple point is interesting to watch. The discovery in the article is regarding water hot enough at high enough pressure to cross this point in nature.
Video of CO2 crossing this point is here;
http://video.google.com/videosearch?q=Carbon+Dioxide+critical&hl=en&emb=0#q=CO2%20phases&hl=en&emb=0 [google.com]
In a nutshell, it's the point where the vapor is just as dense as the liquid state. Watch to video to the triple point.
Re:Can we still blame pollution for this? (Score:3, Informative)
Well, that post of yours could go either sarcastic or honest. Don't know you so...
At any rate, I recall that in my grade 11 Chem course we did a bit on pressure. The teacher created a "vacuum" over a bowl of water at room temperature and it boiled. That's less than an atmosphere difference and boiling. So, imagine what one more atmosphere would do to the boiling point. It'll go up quite a bit. Now try to imagine how much more pressure than that there is down at that depth i.e. at that pressure, it's really really *really* hard to make something boil.
Beyond that, I /could/ open up one of my Physics books and calculate something, but I'm not exactly that enamoured in this problem to do that. But, if you want to...
Re:Start drillin'! (Score:3, Informative)