Tuesday, January 17, 2006
The world’s most technologically advanced exploration ship sails today on a mission that may reveal the origin of life on Earth. The Japanese ship Chikyu intends to drill seven kilometres (4.3 miles) below the sea bed — more than three times deeper than has been done before. It will then raise to the surface a cylinder 1.5m (5ft) long and 15cm wide which could contain science’s first glimpse of a “living” sample of the Earth’s mantle.
The deep-sea drilling vessel Chikyu“The 20th century was all about the origin of matter and the universe, so it seemed useful to go to space and the Moon,” the project’s director general, Asahiko Taira, told The Times. “There were extraordinary advances and we learnt about atoms and the Big Bang. The 21st century is about the fundamental question of where life comes from.” The ship will also be conducting research into the origin of earthquakes. By sinking sensors beneath the Earth’s crust scientists aboard the Chikyu want to provide Japan and East Asia with the first effective earthquake prediction system. The theory behind the life sciences side of the research is that life may have originated beneath the Earth’s crust at temperatures and pressures unknown on land or sea. The energy that provoked the first semblance of life may also have been geothermal rather than solar. Samples of mantle that have been pushed to the Earth’s surface over thousands of years have been studied by scientists but nobody has ever seen a “living” slice or had the opportunity to see whatever micro-organisms may be living there. “This planet is home and we know so little about what is going on just a relatively little distance below our feet. If the secret of life exists to be seen, it is in the deep somewhere,” Dr Taira said. After completing the training missions that begin today, the ship, which cost about £350 million to build and will cost another £50 million for every year it is drilling, will head to the Nankai Trough, 200 kilometres off the coast of Nagoya, where the sea-bed is 2.5 kilometres below the surface. The mission of discovery is not restricted to biology. Physical samples of the mantle are also expected to deliver a rich trove of seismological, volcanic, geological, environmental and climatological information. The reason the Japanese project offers the prospect of such important scientific discoveries is not depth alone. The now-abandoned Russian Kola Well bored nearly 12 kilometres into the Earth, but contributed virtually nothing to science because its entire depth was all in the crust. The Japanese project will be the first to reach the entirely unsurveyed environment of the mantle — the next layer of depth within the Earth — and will do so by exploiting that the Japanese archipelago lies near to a site where main tectonic plates overlap, making it an area where the Earth’s crust is thinner. By boring beneath the seabed the scientists will take advantage that the Mohorovicic Discontinuity (the point where the crust officially becomes the mantle) is nearer than it is on land. Although the international project has the financial and scientific involvement of the US, South Korea, several European countries and China, it is led by the Japan Agency for Marine Earth Science and Technology and is heavily funded by the Japanese taxpayer. The cost can be justified because of what the Chikyu may find about the origins of earthquakes. By drilling to record-breaking depths below areas where tectonic plates overlap, the ship may have its sensors in place as an earthquake begins and significantly advance the science of seismology. Other areas of research include using deep rock samples to construct a better picture of Earth’s environmental history, particularly in the areas under ice caps, which may offer clues to the baffling question of why the polarity of the planet’s magnetic field has repeatedly switched. The project’s chief engineer, Kiyotaka Yamamoto, said: “We will be drilling at possible temperatures of 200C (392F), pressures at which we make industrial diamonds and through rock that even the oil industry has never scratched. Of course there will be failures before we get down there, but this is Japan’s Apollo mission.”