Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New frictional motion study could provide tool for earthquake prediction

27.09.2004


A new study on “waves (or fronts) of detachment” involved in the process of friction offers a new perspective on an old scientific puzzle and could provide a key to improving predictions of future earthquakes, say scientists at the Hebrew University of Jerusalem.


Top illustration shows two surfaces, greatly enlarged, with the microcontacts connecting them. In the middle illustration, the surfaces are starting to move against each other, with the microcontacts being broken. In the bottom drawing, sliding takes place as a slow-motion wave (white area) moves between the surfaces.



The work of the scientists, Prof Jay Fineberg, head of the Hebrew University’s Racah Institute of Physics, Dr Gil Cohen and graduate student Shmuel N Rubinstein, is described in an article in the journal Nature entitled “Detachment Fronts and the Onset of Dynamic Friction.”

Though studied for hundreds of years by names as distinguished as Leonardo da Vinci, and physicists Charles Augustin de Coulomb and Heinrich Rudolf Hertz, the study of friction remains as intriguingly current today as it was 500 years ago. Scientists have yet to fully decipher the fundamental mechanisms of friction – that is, what goes on when two surfaces begin to slide against one another?


Using near-field optics and recent technological advances in rapid imaging, the Hebrew University researchers have observed for the first time how three different types of waves govern the onset of friction. These waves, which function within the micron-thick interface between sliding surfaces, move at widely different velocities, from sonic and supersonic and down to slow speeds. The researchers showed that detachment – the actual separation of the points of microcontact between one surface and another that occurs during frictional movement – is governed mainly by the newly discovered, slow-wave phase.

These findings, says Prof Fineberg, have relevance for the issue of earthquake measurement and predictions, as well as for other future scientific and industrial applications. (Over 5 percent of losses due to both wear and energy dissipation in industry are due to friction, resulting in the loss of hundreds of billions of dollars a year worldwide, says Prof Fineberg.)

An earthquake is felt (and is measured seismically) as a sudden, rapid movement, or sliding, of tectonic plates in a frictional action, says Fineberg. However -- based on the Hebrew University researchers’ findings -- it would seem that it is actually the slow, “unfelt” or “silent” waves in the earth’s crust to which we should be paying closer attention and that are apparently the precursors of the frictional movement that we call earthquakes, says Fineberg.

These waves, though not actually felt, can be measured, Fineberg says, by applying the technology developed on a micro-scale in the Hebrew University laboratories to the macro-scale of sub-surface earth measurements. By doing so, it might be possible to prevent to some extent earthquake-related damage through warnings of approaching “detachment” of earth plates.

Jerry Barach | alfa
Further information:
http://www.huji.ac.il

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>