Did you even know there was a discipline called paleomagnetics? Probably not.(1) It isn't easy to find a category on this site to put it in, that's for sure.
But a discipline it is and it even has its own controversies, as all science must; namely, the nature of Earth's magnetic field 1.1 billion years ago.
The Earth's magnetic field in two sentences: it wraps around the globe and helps shield us from cosmic rays - lest we all burst into flame or turn into orange rock and say things like, "It's clobberin' time!"
If you don't have superpowers or look like a Jack Kirby drawing, blame Earth's magnetic field. © Marvel Comics and/or Disney, depending on when you read this article.
The magnetic field is a result of the planet's iron core, the spinning of the Earth and differences in temperature between the inner core's outer layers and the lower mantle.
Some paleomagnetists believe that the Earth's magnetic field was unstable in the past but a group at Princeton says that, in ancient times, the Earth's magnetic field was structured like the two-pole model of today, suggesting that the methods geoscientists use to reconstruct the geography of early land masses on the globe are accurate.
In other words, the controversy is that there is now no controversy.
By examining t the 1.1 billion-year-old volcanic rocks on the north shore of Lake Superior, they say they have found that Earth's ancient magnetic field was a geocentric axial dipole - that's a large bar magnet centered in the core and aligned with the Earth's spin axis.
So what's the rumpus? Earlier studies of those same rocks led researchers to believe that the magnetic field of ancient Earth had four or even eight poles, which meant that modern models of the supercontinents that relied on that paleomagnetic data and its axial dipole assumption were wrong.
Nope, says the new report in Nature Geoscience, those other researchers were just confused by the migration of the continent toward the equator in the past.
Why does it matter? If we don't know how continents moved in the past and how they massed to form supercontinents, we can't accurately model ocean currents, global average temperatures and wind patterns - which means models of ancient climate would be a lot less made up than they are right now.
You may not have heard of paleomagnetics before but how they deduced this was interesting. They studied the lava flows near previously mentioned Lake Superior, obtained magnetic measurements and used magnetic minerals within the rocks to record the orientation of the geomagnetic field at the time the rocks erupted onto the Earth's surface.
Clever, right? Using the layers, they were able to track how the Earth's magnetic poles have flipped over the eons, when the North Magnetic Pole became the South Magnetic Pole and so on. They studied three of these reversals that occurred over a few million years.
According to recent hypotheses, a supercontinent known as Rodinia (a Russian word meaning “homeland”) existed between 1 billion and 800 million years ago. As it broke up, and the climate cooled 700 million years ago, it is believed the the rapid evolution of primitive life began.
Artist’s conception of the supercontinent Rodinia circa 750 million years ago. What will be North America lies in the center of the surrounding lands. Original painting by Tomo Narashima.
You've probably heard of the Pangaea supercontinent which came together about 300 million years ago and scientists learned about Rodinia in much the same fashion - detective work comparing rocks with similar geological features that are now widely dispersed.
That means the science of ancient geology can be a lot more ... scientific.
(1) Princeton had a paranormal research group for 40 years also. They cover all the bases.
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Sexual Fantasies: Threesomes Are Normal, Golden Showers Not So Much
- Ghost Light From Dead Galaxies - A Hubble Halloween
- US Wildlife Bans On GMOs And Neonics Lack Transparency And Scientific Rationale
- Is It Possible To Build A Spacesuit Or Spaceship To Travel Through The Sun With Future Tech? - Just For Fun.
- Does Max Tegmark Kill A Daughter In A Parallel World ?
- Aging Brains Aren't Necessarily Declining Brains
- The Vampire Deer Of Afghanistan
- "It's good we are still taking advantage of the bounty of the seas. ..."
- "Except you are all forgetting one MAJOR flaw (esp. in regards to Medicare for all..In the words..."
- "It's alive and well! The Maine Seaweed festival just celebrated the growth of kelp farming in Maine..."
- "Verduyn is right on the money when he says it's not the emotion of sadness itself that's inherently..."
- "A very astute observation, given that they're both, in essence, electrical phenomena...."
- Two-faced anti-GMO groups: Block crop and food innovations then claim Big Ag prevents GMO innovations
- Why support erodes for GMO labeling (Hint: It’s not because of spending by Big Ag)
- Genetic “hall of mirrors” with large palindromes, yet smaller: What’s mighty about the mouse
- Gut bacteria an easy scapegoat for disease, but connections hard to prove
- Vermont Rube Goldberg-like GMO labeling law exempts GMO filled natural supplements
- Downside to GMOs: Yields have become so good, they exceed processing capacity