Japan-led research group preparing to drill down to the mantle

Aiming for the world’s first-ever direct excavation of the Earth’s mantle (see below), an international research group led by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) will conduct a preliminary study in the waters off Hawaii in September, The Yomiuri Shimbun learned Tuesday.

The area is considered to be a leading candidate site for the drilling. The research group, including researchers from Japan, the United States and the Europe, plans to intensively investigate the underground structure of the area to find a suitable spot for drilling.

JAMSTEC and its partners aim to realize the excavation of the mantle in the early 2020s — at the earliest — using Japan’s deep-sea scientific drilling vessel Chikyu.

The mantle is located beneath the crust, which covers the surface of the Earth. About 80 percent of the planet’s volume is composed of the mantle. It is formed of rock and moves slowly, affecting the drift of continents, plate movements — which cause earthquakes — and volcanic activity.

http://the-japan-news.com/news/article/0003619423

Oh great, wake up Godzila again.

dv said:

Japan-led research group preparing to drill down to the mantle

Aiming for the world’s first-ever direct excavation of the Earth’s mantle (see below), an international research group led by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) will conduct a preliminary study in the waters off Hawaii in September, The Yomiuri Shimbun learned Tuesday.

The area is considered to be a leading candidate site for the drilling. The research group, including researchers from Japan, the United States and the Europe, plans to intensively investigate the underground structure of the area to find a suitable spot for drilling.

JAMSTEC and its partners aim to realize the excavation of the mantle in the early 2020s — at the earliest — using Japan’s deep-sea scientific drilling vessel Chikyu.

The mantle is located beneath the crust, which covers the surface of the Earth. About 80 percent of the planet’s volume is composed of the mantle. It is formed of rock and moves slowly, affecting the drift of continents, plate movements — which cause earthquakes — and volcanic activity.

http://the-japan-news.com/news/article/0003619423

Later…Volcano eruption at that exact spot.

dv said:

Japan-led research group preparing to drill down to the mantle

Aiming for the world’s first-ever direct excavation of the Earth’s mantle (see below), an international research group led by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) will conduct a preliminary study in the waters off Hawaii in September, The Yomiuri Shimbun learned Tuesday.

The area is considered to be a leading candidate site for the drilling. The research group, including researchers from Japan, the United States and the Europe, plans to intensively investigate the underground structure of the area to find a suitable spot for drilling.

JAMSTEC and its partners aim to realize the excavation of the mantle in the early 2020s — at the earliest — using Japan’s deep-sea scientific drilling vessel Chikyu.

The mantle is located beneath the crust, which covers the surface of the Earth. About 80 percent of the planet’s volume is composed of the mantle. It is formed of rock and moves slowly, affecting the drift of continents, plate movements — which cause earthquakes — and volcanic activity.

http://the-japan-news.com/news/article/0003619423

Yippee, that was supposed to be finished (Mohole project) in the year 1966. It was well worth doing then, it is well worth doing now.

My understanding is that the problem is heat. Boreholes work well enough up to a certain temperature, but have huge problems with failure of the cutting head and collapse of the borehole behind the cutting head at higher temperatures. So, the ideal place to do this project is not necessarily the thinnest part of the crust but instead the coldest part of the mantle.

Now Hawaii is over a hot spot in the mantle, so wouldn’t it be more sensible to drill as far away from Hawaii as possible? Say 2,000 km away.

Tau.Neutrino said:

dv said:

Japan-led research group preparing to drill down to the mantle

Aiming for the world’s first-ever direct excavation of the Earth’s mantle (see below), an international research group led by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) will conduct a preliminary study in the waters off Hawaii in September, The Yomiuri Shimbun learned Tuesday.

The area is considered to be a leading candidate site for the drilling. The research group, including researchers from Japan, the United States and the Europe, plans to intensively investigate the underground structure of the area to find a suitable spot for drilling.

JAMSTEC and its partners aim to realize the excavation of the mantle in the early 2020s — at the earliest — using Japan’s deep-sea scientific drilling vessel Chikyu.

The mantle is located beneath the crust, which covers the surface of the Earth. About 80 percent of the planet’s volume is composed of the mantle. It is formed of rock and moves slowly, affecting the drift of continents, plate movements — which cause earthquakes — and volcanic activity.

http://the-japan-news.com/news/article/0003619423

Later…Volcano eruption at that exact spot.

Is it much different to this:
Project Mohole was an ambitious attempt to drill through the Earth’s crust into the Mohorovičić discontinuity, and to provide an Earth science complement to the high-profile Space Race. The project was initially led by the American Miscellaneous Society with funding from the National Science Foundation.

Tamb said:

Tau.Neutrino said:

dv said:

Japan-led research group preparing to drill down to the mantle

Aiming for the world’s first-ever direct excavation of the Earth’s mantle (see below), an international research group led by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) will conduct a preliminary study in the waters off Hawaii in September, The Yomiuri Shimbun learned Tuesday.

The area is considered to be a leading candidate site for the drilling. The research group, including researchers from Japan, the United States and the Europe, plans to intensively investigate the underground structure of the area to find a suitable spot for drilling.

JAMSTEC and its partners aim to realize the excavation of the mantle in the early 2020s — at the earliest — using Japan’s deep-sea scientific drilling vessel Chikyu.

The mantle is located beneath the crust, which covers the surface of the Earth. About 80 percent of the planet’s volume is composed of the mantle. It is formed of rock and moves slowly, affecting the drift of continents, plate movements — which cause earthquakes — and volcanic activity.

http://the-japan-news.com/news/article/0003619423

Later…Volcano eruption at that exact spot.

Is it much different to this:
Project Mohole was an ambitious attempt to drill through the Earth’s crust into the Mohorovičić discontinuity, and to provide an Earth science complement to the high-profile Space Race. The project was initially led by the American Miscellaneous Society with funding from the National Science Foundation.

Well it will be drilling more than twice as deep (below sea level) than the Project Mohole achieved.

mollwollfumble said:

Now Hawaii is over a hot spot in the mantle, so wouldn’t it be more sensible to drill as far away from Hawaii as possible? Say 2,000 km away.

I don’t know exactly where they are planning to drill but note that
a) the hotspot is now located in south, centred (roughly) on the actual island called Hawaii. Supposedly it is less than 750 km wide.
b)the article says “The preliminary study will be conducted for about two weeks from mid-September in waters northeast of the Hawaiian Islands, using JAMSTEC’s deep-sea research vessel Kaire”, so it might be that where they are drilling is far enough away to be not influenced by the hotspot

dv said:

mollwollfumble said:

Now Hawaii is over a hot spot in the mantle, so wouldn’t it be more sensible to drill as far away from Hawaii as possible? Say 2,000 km away.

I don’t know exactly where they are planning to drill but note that
a) the hotspot is now located in south, centred (roughly) on the actual island called Hawaii. Supposedly it is less than 750 km wide.
b)the article says “The preliminary study will be conducted for about two weeks from mid-September in waters northeast of the Hawaiian Islands, using JAMSTEC’s deep-sea research vessel Kaire”, so it might be that where they are drilling is far enough away to be not influenced by the hotspot

“Less than 750 km wide.” That’s good news.

As for funding, sure the funding strategy is different.

Would it make sense to perhaps drill underneath a relatively recent dormant or extinct volcano as you could have easier access to the mantle as pre-existing tubes feeding the volcano could be drilled into

Cymek said:

Would it make sense to perhaps drill underneath a relatively recent dormant or extinct volcano as you could have easier access to the mantle as pre-existing tubes feeding the volcano could be drilled into

When volcanoes go dormant they tend to freeze, rather than leaving a deep array of empty tubes.

dv said:

Cymek said:

Would it make sense to perhaps drill underneath a relatively recent dormant or extinct volcano as you could have easier access to the mantle as pre-existing tubes feeding the volcano could be drilled into

When volcanoes go dormant they tend to freeze, rather than leaving a deep array of empty tubes.

Yeah I thought that but did wonder if you might be lucky but it would probably take more effort to check them than dig an new hole

Cymek said:

dv said:

Cymek said:

Would it make sense to perhaps drill underneath a relatively recent dormant or extinct volcano as you could have easier access to the mantle as pre-existing tubes feeding the volcano could be drilled into

When volcanoes go dormant they tend to freeze, rather than leaving a deep array of empty tubes.

Yeah I thought that but did wonder if you might be lucky but it would probably take more effort to check them than dig an new hole

drilling through voids is actually a difficult thing to do…

Cymek said:

dv said:

Cymek said:

Would it make sense to perhaps drill underneath a relatively recent dormant or extinct volcano as you could have easier access to the mantle as pre-existing tubes feeding the volcano could be drilled into

When volcanoes go dormant they tend to freeze, rather than leaving a deep array of empty tubes.

Yeah I thought that but did wonder if you might be lucky but it would probably take more effort to check them than dig an new hole

The material that comes up in a volcano isn’t mantle rock, but crustal rock that has been melted by heat from below. There are some very rare occasions when mantle rocks have been brought up part way to the surface by volcanos, but as far as I know this only happened when the Earth was young. It’s worth checking on the web, though.

“Mantle derived xenoliths in India are known to occur in the Proterozoic ultrapotassic rocks like kimberlites from Dharwar and Bastar craton and Mesozoic alkali …”

“14 mantle-derived xenoliths were measured. Samples were eclogites from the Roberts Victor Mine (Orange Free State), peridotites from the Matsoku Pipe (Lesotho) and diopside megacrysts from the four mines in Kimberley.”

“In the few places in the world where these types of xenoliths have been erupted, the xenoliths provide a little insight as to the mineral composition of the upper mantle. Inclusions, such as these xenoliths, are older than the rock itself, i.e., the solidification of the xenoliths had already taken place when they were included in the rising magma body. The composition of the peridotite xenolith defines it as being “ultramafic”. The ultramafic minerals are the first to solidify in a cooling magma.”

Kimberlite is probably best example of material that originated in the mantle.

diddly-squat said:

Kimberlite is probably best example of material that originated in the mantle.

Yes, certainly the best-known example. The purest examples of mantle rock may be the little inclusions that are found inside natural diamonds.

You want to drill through the crust where the seismic shear wave velocity is as high as possible. It varies quite a lot, even over places such as the Pacific oceanic crust.

Bear in mind that the dataset you get from drilling an atypical area that is easy to drill will be of lower value than a more representative dataset.

You don’t want to be like that drunkard looking for his contact lens under the streetlight.
Policeman-“Where did you drop it?”
Drunkard-“Over there in the parking lot.”
Policeman-“So why are you looking here?”
Drunkard-“The light’s better.”

dv said:

Bear in mind that the dataset you get from drilling an atypical area that is easy to drill will be of lower value than a more representative dataset.

You don’t want to be like that drunkard looking for his contact lens under the streetlight.

It’s easier to find typical areas to drill than atypical areas.

For an interesting but confusing discussion of ten or so aspects of the Earth’s mantle under Hawaii in particular and the Pacific in general, see http://www.mantleplumes.org/Hawaii.html