The temperature 3,000 kilometers below the surface of the Earth is much more varied than previously thought, scientists have found
The discovery of the regional variations in the lower mantle where it meets the core, which are up to three times greater than expected, will help scientists explain the structure of the Earth and how it formed.
"Where the mantle meets the core is a more dramatic boundary than the surface of the Earth," said the lead researcher, Associate Professor Hrvoje Tkalči?, from The Australian National University (ANU).
"The contrast between the solid mantle and the liquid core is greater than the contrast between the ground and the air. The core is like a planet within a planet." said Associate Professor Tkalči?, a geophysicist in the ANU Research School of Earth Sciences.
"The centre of the earth is harder to study than the centre of the sun."
Temperatures in the lower mantle the reach around 3,000-3,500 degrees Celsius and the barometer reads about 125 gigapascals, about one and a quarter million times atmospheric pressure.
Variations in these temperatures and other material properties such as density and chemical composition affect the speed at which waves travel through the Earth.
The team examined more than 4,000 seismometers measurements of earthquakes from around the world.
In a process similar to a CT scan, the team then ran a complex mathematical process to unravel the data and build the most detailed global map of the lower mantle, showing features ranging from as large as the entire hemisphere down to 400 kilometres across.
The map showed the seismic speeds varied more than expected over these distances and were probably driven by heat transfer across the core-mantle boundary and radioactivity.
"These images will help us understand how convection connects the Earth's surface with the bottom of the mantle," said Associate Professor Tkalči?.
"These thermal variations also have profound implications for the geodynamo in the core, which creates the Earth's magnetic field."
Dr Hrvoje Tkalcic | EurekAlert!
Multi-year submarine-canyon study challenges textbook theories about turbidity currents
12.12.2017 | Monterey Bay Aquarium Research Institute
How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas
11.12.2017 | Leibniz-Institut für Ostseeforschung Warnemünde
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
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,...
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...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
12.12.2017 | Earth Sciences
12.12.2017 | Power and Electrical Engineering
12.12.2017 | Life Sciences