Slashdot Mirror
The Recent Changes In Earth's Magnetic Field (esa.int)
Europe's Swarm constellation of satellites have documented bigger-than-expected changes that have been occurring in the Earth's magnetic field. Earlier this year SpaceWeather.com reported that the data show clearly that "the field has weakened by about 3.5% at high latitudes over North America, while it has strengthened about 2% over Asia. The region where the field is at its weakest -- the South Atlantic Anomaly -- has moved steadily westward and weakened further by about 2%. These changes have occurred over the relatively brief period between 1999 and mid-2016."
Science writer Robert Zimmerman reports: It was already known that the field has weakened globally by about 10% since the 19th century. These changes appear to be part of that generally weakening. Some scientists have proposed that this is the beginning of an overall flip of the magnetic field's polarity, something that happens on average about every 300,000 years and last occurred 780,000 years ago. At the moment, however, we have no idea if this theory is correct.
Science writer Robert Zimmerman reports: It was already known that the field has weakened globally by about 10% since the 19th century. These changes appear to be part of that generally weakening. Some scientists have proposed that this is the beginning of an overall flip of the magnetic field's polarity, something that happens on average about every 300,000 years and last occurred 780,000 years ago. At the moment, however, we have no idea if this theory is correct.
Actually the tsunami of climate change bollocks in the media and on most websites 24/7 implies precisely that. Nobody talks about natural variation at all.
This is likely nothing to worry about... if as hypothesized it is related to the magnetic flip. As the summary states this happens "on average" every 300000 years, and that's way more frequent than the return period of mass extinctions. Of course, this hypothesis could be wrong...
I like my dinosaurs feathery, and my pterosaurs hairy (or is it pycnofibery?)
You are mistaken about all of that. Current warming is decidedly NOT within the limits and extents of natural variation. The hockey stick graph was not "clearly untrue" and has been supported by more than two dozen reconstructions. The Medieval Warm Period was not a global phenomena and is therefore not comparable. Even if it was global, it still doesn't prove that the current warming is not the result of the greenhouse gases that we produce. That would be the same as saying the since people died before the invention of the gun then being shot won't kill you. Your opinion that the Medieval Warm Period has any relevance here is really down to the likes of Willie Soon, who has since been found to have received money from vested interests like Exxon Mobil and the American Petroleum Institute; a fact that he forgets to mention when he publishes papers on this subject.
If that is the basis of your claim then I stand by my statement that you are inferring the media's cover-up of this based on faulty assumptions.
TIL macro-evolved life wasn't around 780k years ago.
It's an event that's happened 3 times per million years on average for a long, long time that complicated life was around for. Yes, the weakening involved with a flip has had varying severity, but at this point there's a pretty large N.
Will it kill us off? Almost certainly not. Could there be bad cancer rates for a couple or a few generations as a result? Heck yes.
I thought our magnetic field was caused by our molten iron core. Which is not something to undergo rapid changes.
It is called Geomagnetic reversal. The cause is still up for debate, but the magnetic field is produced precisely because the molten core is not static. Have a look at the Wikipedia page for a summary of the phenomenon.