Drilling Hits an Active Magma Chamber In Hawaii

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."

Comments

Old news.... This happened in 2005

[Maddog Batty]

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.

Re:Hot Drill Bit

[syncrotic]

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.

They were scared!

[mangu]

So what were they not confident about?

In 1943 a farmer in Mexico was plowing his field, when smoke started coming from the soil. Today the nearby village is like this.

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

[afidel]

We simply don't have anywhere near the technology to harness this sort of heat into energy.

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:Not granite...

[jolyonr]

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