Scientists discover Earth’s inner-inner core

Scientists from China and United States have discovered that the Earth’s inner core has another core at its centre.

A research team, led by University of Illinois geology professor Xiaodong Song, gathered readings of seismic waves that resonate in an earthquake’s aftermath to probe far below the Earth’s surface, the university said in a statement.

The data show that the Earth’s inner core, which is about the size of the Moon, is in fact made up of two parts. Iron crystals in outer-inner core are aligned in a vertical manner from north to south, while those in the inner-inner core are aligned horizontally from east to west, according to the statement.

“The fact that we have two regions that are distinctly different may tell us something about how the inner core has been evolving,” Song said in the statement. “For example, over the history of the earth, the inner core might have had a very dramatic change in its deformation regime. It might hold the key to how the planet has evolved. We are right in the center – literally, the center of the Earth.”

RUNDOWN SHOWS:
1. Illustration of seismic waves
2. Illustration of using seismic readings to scan the Earth
3. Size of Earth’s inner core in comparison to the Moon
4. The alignment of outer-inner core and inner-inner core

VOICEOVER (in English):
“Researchers gathered seismic waves readings that resonate in an earthquake’s aftermath to probe far beneath the Earth’s surface.”

“The data show the Earth’s inner core, which is about the size of the Moon, is in fact made up of two parts.”

“The iron crystals in the outer-inner core are aligned in a vertical manner from north to south while those in the inner-inner core are aligned horizontally from east to west.”

SOURCES: BBC, University of Illinois, Nature
http://www.bbc.com/news/science-environment-31322817
http://news.illinois.edu/news/15/0209innercore_XiaodongSong.html
http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2354.html