Posted on 12/18/2001 4:04:43 AM PST by blam
Wandering hot spots worry geologists
09:48 18 December 01
Betsy Mason, San Francisco
"Hot spots" where plumes of molten magma break through the Earth's crust appear to be wandering across the planet - a discovery that undermines many of the accepted ideas about how the Earth's tectonic plates are moving.
Geologists thought that magma plumes such as the one that created the Hawaiian Islands remain in place as the plates of the Earth's crust move over them. For years, they have used these hot spots as a fixed frame of reference to gauge the motion of the plates relative to the Earth's core.
The Hawaiian Islands and their underwater neighbours, the Emperor Seamounts, were used by geologists as a record of the path followed by the plate that makes up the floor of the Pacific. The islands formed as the plume of upwelling magma erupted onto the surface of the floor, creating volcanoes.
But a new study by Robert Duncan of Oregon State University in Corvallis and his colleagues shows that the Hawaiian hot spot has probably shifted.
Different directions
The researchers measured the direction in which the minerals in the volcanic rocks of the islands were magnetised. When the lava flows that formed the islands cooled and solidified, the minerals lined up with the Earth's magnetic field, providing a record of their location at the time.
If the islands had all formed in the same place, over a stationary hot spot, they should all have the same magnetic fingerprint. But the minerals line up differently - evidence that the islands formed at different latitudes.
"The reference frame that we were all hanging onto turns out to have legs it can move around on," says team member David Scholl of Stanford University.
Sudden shift
The finding challenges ideas about how the plates have shifted in the past. For example, a prominent bend in the Hawaiian-Emperor seamount chain that occurred 43 million years ago was thought to have been caused when the Pacific plate suddenly changed direction.
Now some geologists are throwing that idea overboard in favour of a moving hot spot.
The idea is likely to be controversial. "People suspected that hot spots were moving," says geologist Robert Butler of the University of Arizona in Phoenix. "But the one they all wanted to hang onto was the biggest, baddest hot spot of them all - the Hawaiian hot spot."
The research was presented at the American Geophysical Union meeting in San Francisco.
Might this not be true for other fields of science, too?
Things that science thought to be inviolate such as evolution and anthropology.
Psychology has already proven to be widely mistaken in some of its "reference frame" facts,
and now geology has been added to that list.
you obviously enjoy having heaps of scorn dropped on you! let me help with your load.
the only true reference point is god. all others are relative and like the hot spots are here today and gone tomorrow. (but relative hot spots can help us get our bearings, as long as we do not place our faith in them.)
Ah ... but you are missing an important point:
Geology accepts the proven changes to its reference frame; Psychology, being merely opinion, does not.
But you'd be hard-pressed to find a college professor who still espouses Frued like in the old days when his theories were considered Gospel.
(Although in the case of Klinton, it still is all about the penis).
Oh, I wasn't conciously trying to bait the evolutionists here - I'm not one to change the subject of a thread.
Besides, I don't have the energy today to engage.
The changes in the magnetic field orientation could just as easily be explained by shift in the Magnetic North Pole. We know for a fact that there have been polarity shifts over geologic time and the current location of the Magnetic North Pole isn't even over the geologic North Pole.
Unless they can rule out these kinds of wobbles, I don't think I'm convinced.
I agree.
Far as I know, nothing in science, including evolution and anthropology, is inviolate. Science is not religion -- it changes constantly to fit the known facts, regardless of what some may say.
It was quite awhile ago that I last read anything about that in the press, but I'm not planning on buying any newly formed property there. It isn't expected to reach the surface of the ocean for another 50,000 years.
There is a fly in the ointment. Earth's magnetic field does not seem to be constant. In fact it changes from day to day.
Sure, it tells me not to jump to conclusions,
it tells me to be wary of jumping on a bandwagon,
and it tells me that perhaps the Nobel Prize committee, in large part, may have another agenda besides the ultimate truth.
(Example: Fofi Annan as Nobel Peace Prize winner).
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