In the high Canadian Arctic, researchers at the University of Rochester have stripped away some of the mystery surrounding the powerhouse that drives the Earths magnetic field. The research strongly suggests that several of the characteristics of the field that were long thought to operate independently of one another, such as the fields polarity and strength, may be linked. If so, then the strength of the field, which has been waning for several thousand years, may herald a pole reversal-a time where compasses all over the Earth would point south instead of north. The findings are being published in todays issue of Proceedings of the National Academy of Sciences.
John Tarduno, professor of geophysics, took 14 students on four excursions, the most recent in the summer of 2000, far above the Arctic Circle to pitch tents near 95-million-year-old rocks on the snow-covered islands of Ellesmere and Axel Heiberg. The rocks, part of a formation called the Strand Fiord, were spewed forth from ancient volcanoes during a time when the Earths magnetic field was particularly stable. As the volcanoes lava cooled to become igneous rock, tiny crystals lined up with the Earths magnetic field and were solidified in the rock. Tarduno was seeking these crystals and the data they preserved about the magnetic field.
Tarduno wanted to find whether the crystals in this region bore evidence of brief fluctuations in the magnetic field. Several more accessible areas of the globe house such crystals, but Tarduno had to go to the edge of the "tangent cylinder"-a giant, theoretical cylinder that runs through the Earth like a pimento through an olive. This cylinder extends away from the Earths solid iron core to the north and south poles and represents an area of possible high turbulence in the molten iron of the core, stirred up by the Earths spin. Near the edge of this cylinder of turbulence scientists believe the liquid iron should be the most chaotic, twisting up the magnetic lines of force. Where this edge contacts the Earths crust high above the Arctic Circle should lie traces of the twisted magnetic field in the crystals.
Jonathan Sherwood | EurekAlert!
In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
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25.09.2017 | Power and Electrical Engineering
25.09.2017 | Health and Medicine
25.09.2017 | Physics and Astronomy