Drilling Hits an Active Magma Chamber In Hawaii 251
Smivs writes "The BBC are reporting that drillers looking for geothermal energy in Hawaii have inadvertently put a well right into a magma chamber.
Molten rock pushed back up the borehole several meters before solidifying, making it perfectly safe to study. Magma specialist Bruce Marsh says it will allow scientists to observe directly how granites are made. 'This is unprecedented; this is the first time a magma has been found in its natural habitat,' the Johns Hopkins University professor told BBC News. 'Before, all we had to deal with were lava flows; but they are the end of a magma's life. They're lying there on the surface, they've de-gassed. It's not the natural habitat.' It is hoped the site can now become a laboratory, with a series of cores drilled around the chamber to better characterise the crystallisation changes occurring in the rock as it loses temperature."
Old news.... This happened in 2005 (Score:5, Informative)
I would love to know why it was kept quiet for so long.
"The breakthrough was made in 2005. Only now are researchers confident enough about their work to discuss the details publicly."
So what were they not confident about? Hot temperatures - check. No drill bit left - check. Rock fused to end of drill - check.
Jon Pertwee era Doctor Who... (Score:1, Informative)
episode comes to mind, called "Inferno"
Drilling into the mantle released some odd mutation that ended up in the destruction of the planet.. (in an alternate reality)
Not granite... (Score:3, Informative)
"Magma specialist Bruce Marsh says it will allow scientists to observe directly how granites are made."
No, because the magma in Hawaii is mafic in composition, yielding basaltic [wikipedia.org] or gabbroic [wikipedia.org]) rocks, not felsic like granites [wikipedia.org]. Maybe they mean being able to observe intrusive processes like the ones that produce granite?
Re:Hot Drill Bit (Score:1, Informative)
http://en.wikipedia.org/wiki/Well_drilling
Re:They found it (Score:3, Informative)
You might not get as much heat conducted into that pipe as you'd hope. Magma has a finite thermal conductivity. More so after it's cooled to the point of solidification.
Re:Hot Drill Bit (Score:3, Informative)
The hole was 2.5km deep. Drill bits are rotational, so the friction with the rocks causes them to reach temperatures above 700 Fahrenheit. Thus they need to be kept cool using liquid coolant. From the article, the magma entered the drill hole, but cooled down after rising a good number of metres before solidifying.
National Driller [nationaldriller.com]
Re:Hot Drill Bit (Score:4, Informative)
You're picturing a drill bit like you'd find on the end of your drill at home, with grooves running all the way up the bit that transport the cuttings to the surface. In rock drilling there's a bit at the bottom of the hole(either percussive or rotary), connected to the drill rig by a pipe of smaller diameter than the bit. Cuttings are forced up through the space between the drill pipe and the wall of the borehole by either high pressure air or water.
Re:They found it (Score:3, Informative)
You mean like copper? Regeneratively cooled rocket engines use copper chambers quite commonly, in an environment far harsher. As long as the cold side has enough coolant flow, the whole chamber (or in this case pipe) stays cool. There's a boundary layer of cooler gas or rock between the copper and the hot stuff that is where most of the temperature difference lies.
For efficiency in a generator, though, you want the highest fluid temperature you can get. Copper would limit the temperature, so you'd probably go for some sort of nickel based superalloy, which would permit operation at temperatures around 1000C.
Sigh... RTFA. (Score:1, Informative)
I take it you didn't read the part where they went into that:
(I know, I know. The article was a *whole* *page* long, and it had to be shipped in from the BCC!)
Re:Not granite... (Score:2, Informative)
Yeah, see, that's what is apparently interesting about this magma - it *is* felsic, in Hawaii, the middle of the bloody Pacific.
They were scared! (Score:5, Informative)
In 1943 a farmer in Mexico was plowing his field, when smoke started coming from the soil. Today the nearby village is like this [wikipedia.org].
Even if the lava in the hole solidified almost instantly, they had to make sure there would be no unforeseen evolution.
Re:They found it (Score:5, Informative)
Like hell we don't, molten salt solar plants use salts that boil at 1400C and magma only reaches about 1300C max, the solidified area that would form around the pipe would lower the delta T to well below what such a system could handle.
Re:They found it (Score:3, Informative)
well if they had some space age, heat resistant pipes to shove down there into the magma, then run some liquid through the pipes to transmit the heat to a steamer
I believe those pipes would need to be made from an alloy known as 'unobtainium'.
Hold a lighter up to the bottom of a plastic water bottle. No, it won't melt. The water keeps it cool. As long as those pipes are always filled with water they won't melt.
Just about every method we use for creating steam uses this concept, from locomotive boilers, to hot water heaters, to the kettle on your stove. Just make sure they don't run dry, or bad things will happen. [wikipedia.org]
Re:Not granite... (Score:5, Informative)
I know this is Slashdot, but perhaps you should read the full article. The magma encountered was unusually high in silica (ie felsic) - a dacite-type lava. They are excited about this because it is showing how granitic continental-style magma can differentiate from your normal basaltic lava.
So yes, it would potentially be granitic rather than gabbroic in nature. Isn't geology fun!
The same thing happens in Iceland too, there are dacite-type and rhyolitic-type lava flows, although a far lower percentage than the normal basaltic flows. Silica-rich lava is a much nastier stuff when it gets to the surface, explosive, but more viscous and less runny than your basaltic lava. That's why you didn't get a geyser of molten-hot lava coming up the tubes [slight simplification, but hey, this is slashdot].
Jolyon
Re:Old news.... This happened in 2005 (Score:4, Informative)
-It's trolling... check
No, it is more like making light of a very serious problem. [ucsusa.org]
Re:They found it (Score:2, Informative)
Let's clear this up - you and a few others seem to have missed the contextual reference to the movie The Core...at least four /.ers got it right though. :)
magma doesn't have a habitat (Score:2, Informative)
Someone should tell these geologists that magma isn't alive and therefore, it doesn't have a habitat. Next thing you know, someone will want to put volcanoes on the endangered species list because we're destroying their "habitat."
Re:They found it (Score:4, Informative)
'unobtainium'
What a disappointment. If only there were some kind of material [scienceblog.com] that could withstand the 1200C of near-surface magma, or some means of rapidly extracting the heat [hoval.co.uk] so we could use it for generating electricity.
Unfortunately, there's no economic incentive [geo-energy.org] to develop these technologies.