Featured Research

from universities, journals, and other organizations

What direction does Earth's center spin? New insights solve 300-year-old problem

Date:
September 16, 2013
Source:
University of Leeds
Summary:
Scientists have solved a 300-year-old riddle about which direction the center of Earth spins. Earth's inner core, made up of solid iron, 'superrotates' in an eastward direction -- meaning it spins faster than the rest of the planet -- while the outer core, comprising mainly molten iron, spins westwards at a slower pace.

Scientists have solved a 300-year-old riddle about which direction the center of Earth spins. Earth's inner core, made up of solid iron, 'superrotates' in an eastward direction -- meaning it spins faster than the rest of the planet -- while the outer core, comprising mainly molten iron, spins westwards at a slower pace.
Credit: KristijanZontar / Fotolia

Scientists at the University of Leeds have solved a 300-year-old riddle about which direction the center of Earth spins.

Earth's inner core, made up of solid iron, 'superrotates' in an eastward direction -- meaning it spins faster than the rest of the planet -- while the outer core, comprising mainly molten iron, spins westwards at a slower pace.

Although Edmund Halley -- who also discovered the famous comet -- showed the westward-drifting motion of Earth's geomagnetic field in 1692, it is the first time that scientists have been able to link the way the inner core spins to the behavior of the outer core. The planet behaves in this way because it is responding to Earth's geomagnetic field.

The findings, published in Proceedings of the National Academy of Sciences, help scientists to interpret the dynamics of the core of Earth, the source of our planet's magnetic field.

In the last few decades, seismometers measuring earthquakes travelling through Earth's core have identified an eastwards, or superrotation of the solid inner core, relative to Earth's surface.

"The link is simply explained in terms of equal and opposite action," explains Dr Philip Livermore, of the School of Earth and Environment at the University of Leeds. "The magnetic field pushes eastwards on the inner core, causing it to spin faster than the Earth, but it also pushes in the opposite direction in the liquid outer core, which creates a westward motion."

The solid iron inner core is about the size of the Moon. It is surrounded by the liquid outer core, an iron alloy, whose convection-driven movement generates the geomagnetic field.

The fact that Earth's internal magnetic field changes slowly, over a timescale of decades, means that the electromagnetic force responsible for pushing the inner and outer cores will itself change over time. This may explain fluctuations in the predominantly eastwards rotation of the inner core, a phenomenon reported for the last 50 years by Tkalčić et al. in a recent study published in Nature Geoscience.

Other previous research based on archeological artefacts and rocks, with ages of hundreds to thousands of years, suggests that the drift direction has not always been westwards: some periods of eastwards motion may have occurred in the last 3,000 years. Viewed within the conclusions of the new model, this suggests that the inner core may have undergone a westwards rotation in such periods.

The authors used a model of Earth's core which was run on the giant super-computer Monte Rosa, part of the Swiss National Supercomputing Centre in Lugano, Switzerland. Using a new method, they were able to simulate Earth's core with an accuracy about 100 times better than other models.

The study was a collaboration between the University of Leeds and the Swiss Federal Institute of Technology, Zurich.


Story Source:

The above story is based on materials provided by University of Leeds. Note: Materials may be edited for content and length.


Journal Reference:

  1. P.W. Livermore, R. Hollerbach and A. Jackson. Electromagnetically driven westward drift and inner-core superrotation in Earth's core. Proceedings of the National Academy of Sciences, 2013; DOI: 10.1073/pnas.1307825110

Cite This Page:

University of Leeds. "What direction does Earth's center spin? New insights solve 300-year-old problem." ScienceDaily. ScienceDaily, 16 September 2013. <www.sciencedaily.com/releases/2013/09/130916162005.htm>.
University of Leeds. (2013, September 16). What direction does Earth's center spin? New insights solve 300-year-old problem. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2013/09/130916162005.htm
University of Leeds. "What direction does Earth's center spin? New insights solve 300-year-old problem." ScienceDaily. www.sciencedaily.com/releases/2013/09/130916162005.htm (accessed September 22, 2014).

Share This



More Earth & Climate News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Hundreds of Thousands Hit NYC Streets to Protest Climate Change

Hundreds of Thousands Hit NYC Streets to Protest Climate Change

AFP (Sep. 22, 2014) Celebrities, political leaders and the masses rallied in New York and across the globe demanding urgent action on climate change, with organizers saying 600,000 people hit the streets. Duration: 01:19 Video provided by AFP
Powered by NewsLook.com
Rockefeller Oil Heirs Switching To Clean Energy

Rockefeller Oil Heirs Switching To Clean Energy

Newsy (Sep. 22, 2014) The Rockefellers — heirs to an oil fortune that made the family name a symbol of American wealth — are switching from fossil fuels to clean energy. Video provided by Newsy
Powered by NewsLook.com
Inside London's Massive Sewer Tunnel Project

Inside London's Massive Sewer Tunnel Project

AP (Sep. 22, 2014) Billions of dollars are being spent on a massive super sewer to take away London's vast output of waste, which is endangering the River Thames. (Sept. 22) Video provided by AP
Powered by NewsLook.com
Washed-Up 'Alien Hairballs' Are Actually Algae

Washed-Up 'Alien Hairballs' Are Actually Algae

Newsy (Sep. 22, 2014) Green balls of algae washed up on Sydney, Australia's Dee Why Beach. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins