Field of Science

At the Earth's Core

Some days ago the Integrated Ocean Drilling Program announced a new record of the scientific vessel "Chikyu" (Japanese for "Earth") - the at this time deepest (scientific) borehole with 2.300 meter depth below the seafloor was completed in the 1.180 meter deep sea of the Shimokita-Peninsula. The longest rig ever done from board of the Chikyu was 7.740 meter long, however in the open sea the greatest problem is not the water, but drilling into the ground. 

Since old times people - especially geologists - were interested to know about the interior of Earth. The Italian poet Dante Alighieri (1265-1321) imagined an allegoric center of the Earth: a frozen wasteland, not reached by the divine light, where Lucifer is entrapped in eternal ice.

Fig.1. Illustration to Dante's "The Divine Comedy" from the "Codice Urbinate Latino 365" (1480) showing the frozen center of Earth.

Jules Gabriel Verne (February 8, 1828 - 1905) was a French author who pioneered the science-fiction genre with novels like "From the Earth to the Moon" (1865), "Twenty Thousand Leagues Under the Sea" (1870), "Around the World in Eighty Days" (1873) and most remarkable for geologists "A Journey to the Center of the Earth" (1864).
Many of the "predictions" of Verne became reality a century later, humans walked on the moon, submarines can travel under the sea and travels around the world are maybe quite a bit expensive, but possible in a shorter time then imagined by Verne.


Still one vision of Verne remains a sci-fi dream - the direct study of earth´s interior...

"Gentleman, the truth is that all our theories are just that, theories. None of us has the least idea of how the earth was really formed. Because the distance between the earths crust and its core is over 6.500 kilometres, and no men has ever descended to a depth of more than 3 miles. So it's obvious, we will never have a glimmer of true knowledge, until we are able to reach a depth of at least a 100 leagues.
- What's your opinion Professor Lindenbrook?
- Well gentlemen, at one point at least I agree with Professor Christophe, the materials of the geologists are not charts, chalk and chatter, but the earth itself. We should never know the truth, until we are able to make that journey, and see for ourselves
."
Dialogue from the Spanish movie "The Fabulous Journey to the Center of the Earth" / "Where Time Began" (1976).


Verne based his imaginary voyage on a more scientific ground than previous authors. In his novel Verne uses the hollow conduit of the Icelandic volcano Snæfellsjökull to venture inside earth, an idea supported by the geologic models of volcanoes proposed at the time - a single or a series of magma chamber(s) with conduits connecting them to the surface. Geologists assumed that during an eruption the magma reservoir becomes empty and large voids and caverns were left behind. 

Fig.2. This geological section, published in the book by German professor of geophysics August Sieberg "Einführung in die Erdbeben- und Vulkankunde Süditaliens" (1914), shows the anatomy of a stratovolcano, with a main conduit, various lateral dikes and a large sill connected to the magma reservoir. In contrast to the sketch, the conduits for magma are in reality only a few meter wide - too small for humans to travel into the Center of the Earth.

Verne's vision was adapted and made popular in the wonderful U.S. movie of 1959 "Journey to the Center of the Earth" and was reused in the mediocre "At The Earth´s Core" (1976, however this movie was based on the novel "At the Earth's Core* by Edgar Rice Burroughs, published in 1914), where even a civilization exists inside earth.


Trailer of the "Journey to the Center of the Earth" adaption of 1959 by Charles Brackett and based on the novel by Jules Verne.
Curious to note that the professor’s name in the original novel was Otto Lidenbrock, a German. In the movie it was changed to Oliver Lindenbrook, a Scotsman. The name of his assistant Axel was also changed into Alec. This was done as tribute to the famous Scottish geologists of the 19th century, like Lyell and Hutton.


 
Trailer of the "Journey to the Center of the Earth" adaption of 1959 by Charles Brackett based on the novel by Jules Verne, see here for Georneys Geo-movie critic.
Curious to note that the professor’s name in the original novel was Otto Lidenbrock, a German. In the movie it was changed to Oliver Lindenbrook, a Scotchman. The name of his assistant Axel was also changed into Alec. This was done because of historical hindsight, as 19th-century Scots had become known as the best field geologists, (remember Hutton and Lyell) with Germans preferring lab-bound geology in the 19th/20th century. - See more at: http://historyofgeology.fieldofscience.com/2011/02/journey-to-center-of-earth.html#sthash.SXOcEOz1.dpuf
Trailer of the "Journey to the Center of the Earth" adaption of 1959 by Charles Brackett based on the novel by Jules Verne, see here for Georneys Geo-movie critic.
Curious to note that the professor’s name in the original novel was Otto Lidenbrock, a German. In the movie it was changed to Oliver Lindenbrook, a Scotchman. The name of his assistant Axel was also changed into Alec. This was done because of historical hindsight, as 19th-century Scots had become known as the best field geologists, (remember Hutton and Lyell) with Germans preferring lab-bound geology in the 19th/20th century. - See more at: http://historyofgeology.fieldofscience.com/2011/02/journey-to-center-of-earth.html#sthash.SXOcEOz1.dpuf
Trailer of the "Journey to the Center of the Earth" adaption of 1959 by Charles Brackett based on the novel by Jules Verne, see here for Georneys Geo-movie critic.
Curious to note that the professor’s name in the original novel was Otto Lidenbrock, a German. In the movie it was changed to Oliver Lindenbrook, a Scotchman. The name of his assistant Axel was also changed into Alec. This was done because of historical hindsight, as 19th-century Scots had become known as the best field geologists, (remember Hutton and Lyell) with Germans preferring lab-bound geology in the 19th/20th century. - See more at: http://historyofgeology.fieldofscience.com/2011/02/journey-to-center-of-earth.html#sthash.SXOcEOz1.dpuf
Trailer of the "Journey to the Center of the Earth" adaption of 1959 by Charles Brackett based on the novel by Jules Verne, see here for Georneys Geo-movie critic.
Curious to note that the professor’s name in the original novel was Otto Lidenbrock, a German. In the movie it was changed to Oliver Lindenbrook, a Scotchman. The name of his assistant Axel was also changed into Alec. This was done because of historical hindsight, as 19th-century Scots had become known as the best field geologists, (remember Hutton and Lyell) with Germans preferring lab-bound geology in the 19th/20th century. - See more at: http://historyofgeology.fieldofscience.com/2011/02/journey-to-center-of-earth.html#sthash.SXOcEOz1.dpuf
Trailer of the "Journey to the Center of the Earth" adaption of 1959 by Charles Brackett based on the novel by Jules Verne, see here for Georneys Geo-movie critic.
Curious to note that the professor’s name in the original novel was Otto Lidenbrock, a German. In the movie it was changed to Oliver Lindenbrook, a Scotchman. The name of his assistant Axel was also changed into Alec. This was done because of historical hindsight, as 19th-century Scots had become known as the best field geologists, (remember Hutton and Lyell) with Germans preferring lab-bound geology in the 19th/20th century. - See more at: http://historyofgeology.fieldofscience.com/2011/02/journey-to-center-of-earth.html#sthash.SXOcEOz1.dpuf
Also the first movie featuring "Superman" touches the subject of a deep-earth civilisation. In "Superman and the Mole Men" (1951) the Mole Men invade earth's surface from the deepest oil well of the world (more than 6 miles/ 9 kilometer deep !).
In fact the deepest boreholes in the real world stopped at more than 12 kilometer - however that's just 0,2% of earth´s radius.
In May 1970, to celebrate the birthday of Lenin, the former Soviet Union initiated the secret project "SG-3" on the Kola-Peninsula. The drilling project planned to study the
Mohorovičić discontinuity, situated at 15 kilometer below the surface of the continents. The project was continued until 1989, when technical and especially financial problems, stopped the drill at 12.261 meter forever.
The United States initiated a similar ambitious project, but decided to drill the thinner oceanic crust (5-10 kilometer thick). Project Mohole started in 1961 and was abandoned in 1966, after recovering 170 meter long cores from the ocean floor in 3.500 meter depth. Modern commercial boreholes reach depths of 2.000-3.000 meter.

Bibliography:

CARLSON, D.H.; PLUMMER, C.C. & HAMMERSLEY, L. (2009): Physical Geology - Earth Revealed. McGraw-Hill Publ, 9th ed.: 645
SCHICK, R. (2002): The Little Book of Earthquakes and Volcanoes. Springer/Copernicus Books, New York: 164