Featured Research

from universities, journals, and other organizations

Earth's core affects length of day

Date:
July 11, 2013
Source:
University of Liverpool
Summary:
Researchers have found that variations in the length of day over periods of between one and 10 years are caused by processes in the Earth's core.

The form of core motions giving rise to variations in Earth’s length of day.
Credit: Image courtesy of University of Liverpool

Researchers studied the variations and fluctuations in the length of day over a one to 10 year period between 1962 and 2012

Research at the University of Liverpool has found that variations in the length of day over periods of between one and 10 years are caused by processes in Earth's core.

Earth rotates once per day, but the length of this day varies. A year, 300million years ago, lasted about 450 days and a day would last about 21 hours.

Length of day increases

As a result of the slowing down of Earth's rotation the length of day has increased.

The rotation of Earth on its axis, however, is affected by a number of other factors -- for example, the force of the wind against mountain ranges changes the length of the day by plus or minus a millisecond over a period of a year.

Professor Richard Holme, from the School of Environmental Sciences, studied the variations and fluctuations in the length of day over a one to 10 year period between 1962 and 2012. The study took account of the effects on Earth's rotation of atmospheric and oceanic processes to produce a model of the variations in the length of day on time scales longer than a year.

Professor Holme said: "The model shows well-known variations on decadal time scales, but importantly resolves changes over periods between one and 10 years.

"Previously these changes were poorly characterised; the study shows they can be explained by just two key signals, a steady 5.9 year oscillation and episodic jumps which occur at the same time as abrupt changes in the Earth's magnetic field, generated in the Earth's core.

He added: "This study changes fundamentally our understanding of short-period dynamics of the Earth's fluid core. It leads us to conclude that the Earth's lower mantle, which sits above the Earth's outer core, is a poor conductor of electricity giving us new insight into the chemistry and mineralogy of the Earth's deep interior."

The research was conducted in partnership with the Universitι Paris Diderot and is published in Nature.


Story Source:

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


Journal Reference:

  1. R. Holme, O. de Viron. Characterization and implications of intradecadal variations in length of day. Nature, 2013; 499 (7457): 202 DOI: 10.1038/nature12282

Cite This Page:

University of Liverpool. "Earth's core affects length of day." ScienceDaily. ScienceDaily, 11 July 2013. <www.sciencedaily.com/releases/2013/07/130711103156.htm>.
University of Liverpool. (2013, July 11). Earth's core affects length of day. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2013/07/130711103156.htm
University of Liverpool. "Earth's core affects length of day." ScienceDaily. www.sciencedaily.com/releases/2013/07/130711103156.htm (accessed September 17, 2014).

Share This



More Earth & Climate News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) — Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) — A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Researchers Explore Shipwrecks Off Calif. Coast

Researchers Explore Shipwrecks Off Calif. Coast

AP (Sep. 16, 2014) — Federal researchers are exploring more than a dozen underwater sites where they believe ships sank in the treacherous waters west of San Francisco in the decades following the Gold Rush. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Isolated N. Korea Asks For International Help With Volcano

Isolated N. Korea Asks For International Help With Volcano

Newsy (Sep. 16, 2014) — Mount Paektu volcano in North Korea is showing signs of life and there's not much known about it. 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