Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists probe Earth's core

29.04.2010
University of Calgary researchers listen to earthquake "whispers" reveals new clues about Earth's formation

We know more about distant galaxies than we do about the interior of our own planet. However, by observing distant earthquakes, researchers at the University of Calgary have revealed new clues about the top of the Earth's core in a paper published in the May edition of the journal Physics of the Earth and Planetary Interiors.

Knowledge of the composition and state in this zone is key to unraveling the source of the Earth's magnetic field and the formation of our planet.

"Some scientists have proposed a region of sediment accumulation at the top of the core, or even distinct liquid layers, but this study shows that the outer core is, in fact, well mixed," says professor Dave Eaton, co-author of the paper. "This inaccessible region is composed of molten iron, nickel and other as-yet unknown lighter elements such as silicon, sulfur, carbon or oxygen."

To help try and determine the materials that make up the Earth's core, which is 2,891 km below the surface, Eaton and co-author Catrina Alexandrakis, University of Calgary PhD student, measured the seismic wave speed (speed of sound) at the top of Earth's core.

"Observation of distant earthquakes is one of the few tools that scientists have to investigate deep parts of the Earth," says Alexandrakis. "This isn't the first time earthquake data has been used, but our research method is the most definitive to date."

The researchers' method is based on 'listening' to earthquakes on the other side of the planet using an approach that is akin to hearing a conversation across a whispering gallery, such as those in the domes of some large cathedrals.

Using a novel digital processing approach, they analyzed faint signals, produced by 44 earthquakes, and were able to measure the sound speed at the top of Earth's core with unprecedented accuracy.

Their results will help to guide research efforts at laboratories where core composition is studied by simulating extreme pressure and temperature conditions that exist in the Earth's core.

Precise seismic-wave velocity atop Earth's core: No evidence for outer-core stratification by Catherine Alexandrakis and David Eaton is published in the journal Physics of the Earth and Planetary Interiors: http://dx.doi.org/10.1016/j.pepi.2010.02.011

Grady Semmens | EurekAlert!
Further information:
http://www.ucalgary.ca

More articles from Physics and Astronomy:

nachricht Smallest transistor worldwide switches current with a single atom in solid electrolyte
17.08.2018 | Karlsruher Institut für Technologie (KIT)

nachricht Protecting the power grid: Advanced plasma switch for more efficient transmission
17.08.2018 | DOE/Princeton Plasma Physics Laboratory

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

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....

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

Quantum bugs, meet your new swatter

20.08.2018 | Information Technology

A novel synthetic antibody enables conditional “protein knockdown” in vertebrates

20.08.2018 | Life Sciences

Metamolds: Molding a mold

20.08.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>