African rocks record ancient magnetic field
2010 05 05
By Jonathan Amos | BBCNews.co.uk
Scientists have managed to push back the date for the earliest known presence of a magnetic field on Earth by about 250 million years.
The evidence is seen in tiny iron minerals that are aligned inside ancient dacite rocks from the Barberton mountains in South Africa.
Analysis of the 3.45-billion-year-old minerals indicates the strength the field was much weaker than today.
Earth’s magnetic field protects all life on the planet.
It forms a shield that deflects harmful particles from the Sun around our world, and limits the ability of this "solar wind" to erode our atmosphere.
The new work by Professor John Tarduno, from the University of Rochester, US, and colleagues has been discussed at a major Earth sciences meeting in Vienna, Austria.
"Earth’s magnetic field is important to us," Professor Tarduno told the European Geosciences Union meeting.
"[3.45 billion years ago] is a really critical time because it’s when we start seeing the first tentative signs of life, so perhaps these two things are linked together."
The Rochester team has developed techniques for studying tiny magnetite minerals trapped inside the crystals of volcanic rock.
These minerals orientate themselves with respect to the Earth’s magnetic field in a cooling magma and lock their positions once the temperature in the host rock dips below 580C.
The Barberton samples indicate the nascent field was considerably weaker than today’s protective shield.
Whereas the modern boundary between our planet’s magnetosphere and the solar wind might be located ordinarily at about 10 Earth radii, the ancient boundary would have been much closer - perhaps three to five Earth radii, said Professor Tarduno.
He explained that one likely effect of this would have been the production of polar lights, or auroras, at much lower latitudes as many more solar particles breached the shield to collide with atmospheric molecules.
It probably also meant the atmosphere lost more of its lighter elements, like hydrogen, faster than had previously been supposed, argued Professor Tarduno.
The Barberton greenstone belt preserves some of the oldest rocks on the planet.
"What that means in an evolutionary sense to us - and this is just speculation but something we want to follow it up - is that perhaps this is suggesting the Earth was much more water-rich very early on," he said.
"If, even with this magnetic field, we are losing hydrogen and water, that would suggest the palaeo-Earth in its infant state must have had more water than we think about today."
Professor Tarduno’s team is now looking back still deeper into the past for evidence of a global magnetic field.
The field is generated by convection currents in the molten-iron outer-core of the planet, and finding evidence of an even more ancient field would say much about the interior state of the young Earth.
There are volcanic rocks in Africa, India and Australia that possibly retain a record that is 3.6bn years old.
"To go back even further in time, however, we don’t have the rocks available. But what we do have is certain younger sedimentary rocks that record minerals which were eroded from more ancient rocks - as old as four billion years old," Professor Tarduno told BBC News.
"We are developing techniques and we believe we can actually record the Earth’s magnetic field in these minerals also."
Article from: news.bbc.co.uk
2012: Leaks Found in Earth’s Magnetic Field
Video from: YouTube.com
Origin of Earth’s Magnetic Field
Video from: YouTube.com
Also tune into:
Walter Cruttenden - Lost Star of Myth and Time, Rise and Fall of Civilization and Consciousness
Walter Cruttenden - Sirius, The Binary Star & Precession
Rens van der Sluijs - Plasma Mythology & The Axis Mundi
Wallace Thornhill - The Electric Universe
William Henry - The Apotheosis is at Hand, NWO, COP15, Norway Blue Spiral & Stargates
Edmund Marriage - Global Catastrophe, Restart of Civilization & The Anu-Nagi (The Shining Ones)
Earth’s Magnetic Field - Wikipedia
Earth’s Magnetic Field Is 3.5 Billion Years Old
Intro to magnetic fields - What is the structure of the Earth’s magnetic field?
Magnetite - Wikipedia
Henges: Stonehenge, Woodhenge, Avebury & Stanton Drew (Video)
Moral judgments can be altered ... by magnets
Earth’s north magnetic pole racing towards Russia due to core flux
Nathan Stubblefield and Electromagnetism
Russians order Flight Changes, after Massive Magnetic Shift downs Airliners
Playing the Field: Geomagnetic Storms and the Stock Market
’Hidden Portal’ Concept Described: First Tunable Electromagnetic Gateway
Chris Dunn & Great Pyramid 3D Electromagnetic Power Plant Walkthrough (Video)
Oceans charge up new theory of magnetism
Mayan Calendar & Human DNA II - Prophesies & Sun Magnetic Reversals - part 1 (Video)
Sweet dreams are made of geomagnetic activity
Magnetic Portals Connect Sun and Earth
Phoenix Pole Shift
Latest News from our Front Page
The Aeon of Horus is Ending and the Elites are Nervous as their Icons are Dying
2014 04 18
I predict there is going to be a huge resurgence of interest in European indigenous spiritual traditions from Norse to Celtic/Gaelic to Slavic and so on. Millions of Europeans are going to realise that we are the victims of Christianity and New Age garbage. Their bastardised Kabbalah, the psychic force used by Crowley and the elites to cement his Aeon ...
Easter - Christian or Pagan?
2014 04 18
Contrary to popular belief, Easter does not represent the "historical" crucifixion and resurrection of Jesus Christ. In reality, the gospel tale reflects the annual "crossification" of the sun through the vernal equinox (Spring), at which time the sun is "resurrected," as the day begins to become longer than the night.
Rather than being a "Christian" holiday, Easter celebrations date back ...
Man-Made Blood Might Be Used in Transfusions by 2016
2014 04 18
Researchers in the U.K. have created the first man-made red blood cells of high enough quality to be introduced into the human body
The premise of the HBO show and book series True Blood revolves around a technological breakthrough: scientists figure out how to synthesize artificial human blood, which, as an ample new source of non-human food, allows vampires to "come ...
The Trials of the Cherokee Were Reflected In Their Skulls
2014 04 18
Researchers from North Carolina State University and the University of Tennessee have found that environmental stressors – from the Trail of Tears to the Civil War – led to significant changes in the shape of skulls in the eastern and western bands of the Cherokee people.
The findings highlight the role of environmental factors in shaping our physical characteristics.
Our Fears May Be Shaped by Ancestral Trauma
2014 04 18
Last December, an unsettling Nature Neuroscience study found that mice who were taught to associate the smell of cherry blossoms with pain produced offspring who feared the smell of cherry blossoms, even if they had never been exposed to it before. We knew that the process was epigenetic—that it was not hard-wired in the permanent genetic structure of the mouse—but ...
|More News » |