Researchers have developed a lab model to find out the materials present in the Earth’s outer core.
This research has been done by the Yingwei Fei, a geochemist at the Carnegie Institution for Science in Washington, D.C. and collaborators, and published in the November 23 issue of the journal Nature.
According to researchers, this study could solve about 60 years old argument about the Earth’s core, in which two groups of scientists argue whether core has oxygen as the most common light element or sulfur.
Researchers have found that oxygen is making only a small percentage of the Core’s material. They have suggested that sulfur and silicon can be in more abundance in the core of the Earth. They made two samples in the lab in which iron was placed along with 8% oxygen and 2% sulfur by weight in one sample and 2.2% oxygen and 5.3 % sulfur in the other sample. They then used a high-pressure machine to send shockwaves through the samples making them to work like deep inside the Earth.
They found that sample with 2.2% oxygen better match the properties of Earth’s depth. Additional calculations showed that 0.5% oxygen showed better match to reality.
The results show that we can rule out oxygen as a major light element in the liquid outer core because adding oxygen into liquid iron would not reproduce simultaneously the observed density and sound velocity profiles of the outer core. An oxygen-depleted core would imply a more reduced environment during early Earth accretion.
Researchers are working on the Earth’s core to find the mechanism through which Earth is clumped about 4.5 billion years ago.
Haijun Huang, Yingwei Fei, Lingcang Cai, Fuqian Jing, Xiaojun Hu, Hongsen Xie, Lianmeng Zhang & Zizheng Gong, (2011). Evidence for an oxygen-depleted liquid outer core of the Earth. Nature, doi:10.1038/nature10621