Wednesday, June 2, 2010

Earth's outer core consists of which materials?

Despite an impressive technological advances scientists still know very little about Earth's interior. It is a bit odd that we seem to be gathering knowledge about distant planet and far galaxies while at the same time we know so little about our own planet.

Scientists at the University of Calgary hope to put more light on the interior of our planet, specifically the outer core, and their latest findings have been published in the May edition of the journal Physics of the Earth and Planetary Interiors.

They have gathered valuable data by observing distant earthquakes, and according to them these earthquakes can provide valuable clues about Earth's outer core. One of the lead scientists, professor Dave Eaton, said that Earth's outer core is composed of molten iron, nickel and other as-yet unknown lighter elements such as silicon, sulfur, carbon or oxygen.

Earth'c core is located almost 3,000 km below the surface (2,891 km), and in order to determine of which materials does the earth's core consists scientists measured the seismic wave speed (speed of sound) at the top of Earth's core.

This method isn't exactly novelty but scientists from the University of Calgary used brand new digital processing approach, which helped them analyze faint signals, produced by 44 earthquakes, and with it they were able to measure the sound speed at the top of Earth's core with unprecedented accuracy.

The results of this study should be of great help to research efforts at laboratories where core composition is studied by simulating extreme pressure and temperature conditions that exist in the Earth's core.