Journey Towards The Center of the Earth

linumax wrote to mention an article detailing an ambitious Japanese-led voyage towards the center of the earth. From the article: "The deep-sea drilling vessel Chikyu made a port call Thursday in Yokohama after ending its first training mission at sea since being built in July at a cost of 500 million dollars. The 57,500-ton Chikyu, which means the Earth in Japanese, is scheduled to embark in September 2007 on a voyage to collect the first samples of the Earth's mantle in human history. The project, led by Japan and the United States with the participation of China and the European Union, seeks clues on primitive organisms that were the forerunners of life and on the tectonic plates that shake the planet's foundations" They also hope to use the information to detect earthquakes more accurately. A 4 page PDF presentation about the Chikyu deep-sea drilling vessel is also available."

Comments

Center of the Earth?

[fanblade]

"on a voyage to collect the first samples of the Earth's mantle in human history"

Mantle != Core

Re:Center of the Earth?

[Wyatt Earp]

"Yeah, but the mantle is mostly liquid, right? So we should be able to dump a capsule with measuring equipment on it and wait for it to "sink"'

No, it's mostly solid rock, mantle rock consists of olivines, mantle rocks also possesses a higher portion of iron and magnesium and a smaller portion of silicon and aluminium than the crust. In the mantle, temperatures range between 100C at the upper boundary to over 3,500C at the boundary with the core. Although these temperatures far exceed the melting points of the mantle rocks at the surface, particularly in deeper ranges, they are almost exclusively solid. The enormous pressure exerted on the mantle prevents them from melting.

Re:I've always wondered...

[pin_gween]

I thought the Russians had been drilling for a long time. They had reached 40,000 ft by 1985

A major problem they will encounter is the plasticity of rocks as the approach the mantle -- the heat and pressure allows rocks to flow, much like silly putty will ooze. That plasticity make it difficult to maintain an open well for the bit to drill through.

Re:I've always wondered...

[LeadfootCA]

The mantle is composed primarily of solid rock. From Wikipedia:

Mantle rock consists of olivines, different pyroxenes and other mafic minerals. Typified by peridotite, dunite, and eclogite, mantle rocks also possesses a higher portion of iron and magnesium and a smaller portion of silicon and aluminium than the crust. In the mantle, temperatures range between 100C at the upper boundary to over 3,500C at the boundary with the core. Although these temperatures far exceed the melting points of the mantle rocks at the surface, particularly in deeper ranges, they are almost exclusively solid. The enormous lithostatic pressure exerted on the mantle prevents them from melting.

Re:Journey to the center of the earth?

[Anonymous Coward]

Maybe that's why the submission is cleverly titled "Journey towards the center of the earth"?

Re:thin crust, extra cheese

[jdhutchins]

They're drilling through the ocean floor, not from land- so the ocean takes care of a bunch of the crust for them.

Re:Detecting quakes? What about causing them?

[BrynM]

the field shift is kind interesting considering it is accelerating. And acceleration can't occur without an outside force acting on it.

Here's some better info on the magnetic field. I doubt an outside force needs to be involved with something as dynamic as the mantle. It's pretty much a world of it's own within ours.

Re:The Atheist Agenda

[dcapel]

What do you mean God?

It was the Flying Spaghetti Monster, you insensitive clod!

Those pesky kanji...

[gnownaym]

If anyone's interested, the kanji (Chinese-derived characters) for "chikyuu" are (if this shows up at all):

(if that didn't work, try this one: http://www5.big.or.jp/~otake/hey/kanji/gifmoji/f5/ chikyuu.gif)

where the first one is read "chi", meaning earth (in the dirt sense). The second is read "kyuu" and means "ball".

So. Welcome to my planet, dirtball.

Re:That drill bit better ...

[Chowderbags]

A believable framework? Fooled this guy...: http://www.intuitor.com/moviephysics/core.html

Dupe...of course

[Anonymous Coward]

This was posted long ago: http://science.slashdot.org/article.pl?sid=05/06/0 4/0526254&tid=14