Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tracking Earth's Wobbles Down to the Size of a Cell Phone

26.06.2006
New technologies are enabling scientists to determine precisely the extent and causes of Earth's short-term wobbling. Like a spinning top, Earth wobbles as it rotates on its axis. In fact, it displays many different wobbling motions, ranging in period from a few minutes to billions of years. Some of these are well studied, like the Chandler wobble of 433 days and the annual wobble, which together can tilt Earth's axis up to 10 meters [30 feet] from its nominal center.

Earth's irregular, shorter term wobbles, lasting a week or so, have been more difficult to study, partly because these motions are usually masked by those of more prominent wobbles. Now, scientists in Belgium and France have taken advantage of a quirk in the pattern of large-scale motions and the advent of the Global Positioning System (GPS) to pin down short-term wobbles that occurred from November 2005 through February 2006.


Motion of the North Pole, as determined by the IERS. Earth Orientation Parameter Center of the Paris Observatory, for the study period, 1 November 2005 to 14 February 2006. Each marker represents the position of the pole on one day. Five loops are identified. Never before have these small polar movements been traced with such precision.

During this period, the Chandler wobble and the annual wobble essentially cancelled each other out, an event that occurs every 6.4 years, allowing the researchers to focus on the short-period wobbles. Over these three and a half months, the pole position traced small loops, ranging in size from that of a sheet of A4 [8-1/2x11 inch] paper down to that of a cell phone, and it remained within a one meter [yard] square during these four months.

Sebastien Lambert of the Royal Observatory of Belgium and colleagues there and at the Paris Observatory took advantage of the opportunity to track short-term wobbles, using newly available GPS data that establish the location of the poles precisely. They then sought to determine why these motions occurred when they did.

In a paper scheduled to be published 1 July in Geophysical Research Letters, they conclude that weather patterns in the northern hemisphere played a significant role. Both the location of high- or low-pressure centers--for example, over Asia or northern Europe--and the relationship of these weather systems to each other played a measurable role in creating, or "exciting," small, short-term wobbles, they report.

The ocean also affects short-term wobbles, according to Lambert and his colleagues. They were able to correlate oceanic and atmospheric pressure variations with the small observed wobbles during the study period. Although these forces had been credited by previous researchers with maintaining the large Chandler wobble, this was the first time that scientists have been able to demonstrate that day-to-day changes in atmospheric pressure produce a measurable effect on Earth's rotation.

The study was funded by the Belgian Science Policy Office, the Royal Observatory of Belgium, and the Paris Observatory.

Harvey Leifert | American Geophysical Union
Further information:
http://www.agu.org

More articles from Earth Sciences:

nachricht Six-decade-old space mystery solved with shoebox-sized satellite called a CubeSat
15.12.2017 | National Science Foundation

nachricht NSF-funded researchers find that ice sheet is dynamic and has repeatedly grown and shrunk
15.12.2017 | National Science Foundation

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>