[Rockhounds] Hawaii's Moving Hot Spot

[William Dicks]

Thanks Pete.
This is just what I was looking for. I hadn't made the link to Kittys'
"aside" being different.
I have my students use a 1992 Nat Geo map of the Pacific Ocean Floor to
trace, among other things, the movement of the plate.
Obviously a moving hot spot would affect this work.
Further south, east of Australia you can find similar data. The Tuamotu
Archipelago mimics the Hawaiian Islands and the Line Islands mimic the
Emperor Seamounts. Would this mean a hot spot east of Australia also
moves?????? How odd!!!
I'll check out your google link.
Once again Rockhounds come thru. The list never fails to impress :-)))
Thanks again

Bill Dicks
Teacher,
Northville High School
Board Member,
Michigan Earth Science Teachers Association


>>> Pmodreski at aol.com 01/03/08 9:00 AM >>>
 
In a message dated 1/3/2008 4:47:22 AM Mountain Standard Time,  
DicksWi at northville.k12.mi.us writes:

Kitty  (or anyone else for that matter......)
I have skimmed thru  the link you provided for information on Lo'ihi
but can't find reference to  the moving hot spot.
As an educator I'd like to have/read the article or  any scientific
data/findings reporting on the moving hot  spot.



Hi, here's a reply from "anyone else", I'm interested in this too,
 
I don't think the matter of the moving hot spot has anything to do with
 
Loihi, that was just an aside from Kitty about interesting stuff about
Hawaiian  
volcanism...
 
I did a little Googling and came up with a good National Geographic
article  
about the "moving hot spot" research.  Here's the link,
 
_http://news.nationalgeographic.com/news/2003/08/0814_030814_hotspot.html_

(http://news.nationalgeographic.com/news/2003/08/0814_030814_hotspot.html)

which says in part,
 
"A recent discovery that the so-called "fixed" hot spot, which created
the  
Hawaiian Islands, actually drifted southward between 81 and 47 million
years 
ago  is causing geologists to revise their descriptions of the interior
workings 
of  the Earth. 
 
"...they create strings of seamounts and volcanic islands that are
believed  
to tell the story of how the overlying plates moved over time.  
"A well-known example of this phenomenon is the Hawaii-Emperor Seamount
chain 
 that stretches some 3,000 miles (5,800 kilometers) along the floor of
the  
Pacific Ocean from the Big Island of Hawaii to Alaska's Aleutian
Trench.  
"At the end of the Northwestern Hawaiian Islands, the chain turns
sharply  
northward and becomes the Emperor Seamounts, which stretch to their
intersection 
 with the Aleutian Trench at the Kamchatka Peninsula in Siberia.  
According to most researchers, this sharp bend represents a rapid
change in  
direction of the Pacific Plate as it passed over the fixed hot spot 47
million 
 years ago.  
"Tarduno and colleagues found that the hot spot actually crept
southward at a 
 rate of about 1.6 inches (40 millimeters) per year between 81 and 47
million 
 years ago. 
 
"The new findings were published late last month on Science Express, 
the 
online research journal of the American Association for the Advancement
of  
Science, and will be published in an upcoming issue of the print
journal  Science. 
" 
So, the "moving hot spot" is based on studies of old seamounts far west
of  
Hawaii itself, and the motion took place between 81 and 47 millions
years ago;  
they are concluding that the "spot" (the inferred mantle magma plume)
was 
moving  then, and is more stationary now, as the Pacific plate moves
over it. 
Pete



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