According to the Japanese scientists silicon is possibly the mystery element in the Earth’s inner core and can be used to solve one of the planet’s deepest secrets.
Earlier agreement has been that the centre of the planet Earth is composed of more than 85 percent iron and 10 percent nickel, with sulphur, oxygen and silicon prime candidates for the other five percent. But geophysicist Eiji Ohtani at Tohoku University in northern Japan and his research team have suggested that silicon is the most probably the element to be considered.
Ohtani’s team also conducted further experiments on iron-nickel alloys mixed with silicon, exposing them in the lab to the kinds of high temperatures and pressure found in the inner core. Expectedly it was discovered that the data for the mixed material observed with X-rays matched the seismic data- namely, sound velocity, or seismic waves which were obtained for the inner core of Earth.
Professor Ohtani told AFP , “Our latest experiments suggest that the remaining five percent of the inner core is composed mostly of silicon,” He also said “the finding helps understand whether the Earth’s surface was rich in oxygen in its early formation before photosynthesis began as oxygen has been another potential candidate for the mystery element in the Earth’s inner core.”
Ohtani later declared that more work needs to be done in order to confirm his findings on silicon to revel Earth’s core history.
Some scientists even believe that if the Earth’s inner core contains silicon then it means the rest of the planet must be moderately oxygen rich at the time of its formation. This is because it was earlier believed that oxygen existed when the planet was formed but was not confined to the inner core. But controversies arise like if the mystery element in the core is oxygen then the rest of the Earth must have been oxygen-poor in the beginning.
Ohtani later clarified that he does not think oxygen any more exists in the inner core of Earth, and explained the difficulty for silicon and oxygen to co-exist in the same place. “But it doesn’t necessarily mean the rest of the planet was oxygen rich because there is a possibility that oxygen did not exist as an element of the Earth at its formation in the first place.” said Ohtani.
Earlier the Earth was believed to be made up of three main layers: the solid outer layer where creatures including humans live, the mantle which is made up of hot magma and other semi-solid materials, and the core at the centre. The core is the outer layer of Earth’s crust made up of liquid iron and nickel, and an inner layer a hot dense ball of mostly ferrous.
Ohtani has presented his team’s work at a meeting in December of the American Geophysical Union in San Francisco, and is preparing to submit a research paper on the same.