Surprisingly rapid changes in the Earth's core discovered
July 7th, 2008In a recent paper published in Nature Geoscience, the geophysicist Mioara MANDEA from the GFZ German Research Centre for Geosciences, Potsdam and her Danish colleague Nils OLSEN from the National Space Institute/DTU Copenhagen, have shown that motions in the fluid in the Earth’s core are changing surprisingly fast, and that this, in turn, effects the magnetic field of our Planet.
The very precise measurements of the Earth’s magnetic field delivered by the geosatellite CHAMP combined with Ørsted satellite data and ground observations over the past nine years, have made it possible to reveal what is happening at 3000 km under our feet.
Indeed, for the first time, Nils Olsen and Mioara Mandea have computed a model for the flow at the top of the Earth’s core that fits with the recent rapid changes in the magnetic field, and is also in agreement with the changes in the Length-of-Day variation.
This core flow is rather localized in space, and involves rapid variations, almost sudden, over only a few months – a remarkably short time interval compared with the respectable age of our Planet or even with the time of the last magnetic field reversal, some 780000 years ago.
Scientists from the Helmholtz Centre GFZ and other institutions are currently involved in the ESA Swarm mission, which will follow on the CHAMP achievements. The Swarm constellation consists of three CHAMP-type satellites, which will measure the Earth’s magnetic field even more accurately than before.
Citation: Rapidly changing flows in the Earth’s core, Nils OLSEN and Mioara MANDEA, Nature Geoscience 1, 390 - 394 (18 May 2008), doi: 10.1038/ngeo203
Source: Helmholtz Association of German Research Centres
Jun 29, 2009 |
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I just want to know if this is predicted to be a factor in global climate models as having any effect. There is a bunch of mention of it out there on the internet - but I am wondering what the "party line" ,if any, is on this correlation from the scientific community.
Posted below - just some fodder from the Internet:
Having been sited to cut the deepest Antarctic ice known, it seems to me likely that at the time of the last reversal of the earth's magnetic field, about 780,000 years ago, all the ice in Antarctica very likely melted away. So there may be no older ice to be found. Deep ice core drillers are still hoping to get beyond the million-year mark. I hope they do, but I do not fancy their chances
I'm not speaking with authority, but it is logical to think that with a declining magnetic moment (such as that of the Earth's), more solar ions and radiation will penetrate the Earth's magnetosphere and ionosphere, particularly at polar latitudes. This may lead to lower latitude, more intense aurora, and consequently more heat being dumped into the Earth's environment.
Curiously, almost all the Arctic ice melts away every summer now. I've never heard of any correlations between the previous pole shift and a lack of Antarctic ice... However, if that hypothesis is true, it could explain recent sea ice observations, as it is widely agreed we are in the starting era of another pole shift (which may take anywhere from 3,000 to 30,000 years to complete, from the best models).
Even if it is hookey, it would make a great basis for a sci-fi movie where mutants take over the earth. =)
If you could point me in the direction of a paper published on these subjects, I would be very greatful. I will be checking out your book, however.
Everything I didn't quote, I more or less agree with.
Also, if the extra heat you hypothesize being pumped into the planet by this mechanism was actually present, we would have observed heating throughout the stratosphere in the places that the heat enters. What we actually observe is heating confined to the lower atmosphere, indicative of warming caused by the greenhouse effect. http://en.wikiped...e_effect