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Old 24-09-2008, 12:37   #1
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This Is Really an Interesting Read ! Beveridge Reef and Niue

Geography and geology of Niue ~ by Dr J Floor Anthoni

Geography of Niue

The water covering Beveridge Reef is a result of the gravitational anomaly caused by the 18000 ft needle-like sea mount which pulls the water upward.

Bathymetry
In 1978, an experimental satellite was launched to study the oceans. One of Seasat's instruments was a radar altimeter, able to measure the ocean's surface from an altitude about 500 miles up, with a precision of 5-10 cm. Surprisingly, the surface of the ocean proved to be curving and dipping, often by as much as 10m up and down (for 5000m bottom relief). When mapped, the dips corresponded to dips in the sea floor and the bumps to sea mounts and ridges. The precision of the measurements allowed computers to make precise and detailed maps of the entire world's ocean floors.
The reason these dips and bumps occur in the ocean's floor, without ships ever being able to notice these, comes from the force with which two substance attract one another - the heavier earth's crust attracting the lighter and fluid water. Thus undersea mountains pull water towards them, resulting in a surface bump, whereas ocean trenches have the opposite effect.



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Old 24-09-2008, 13:40   #2
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Back in my day, we used to have to sail up hill!
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Old 31-10-2008, 17:44   #3
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I find the whole concept fascinating.
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Old 31-10-2008, 23:01   #4
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Does this mean that if you were to anchor on Beveridge Reef, you could never leave it?
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Old 01-11-2008, 01:13   #5
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Thanks for reminding us about Dr Anthoni’s excellent Seafriends home page website.

Other articles of interest by Dr J Floor Anthoni:
Oceanography index

Including:

Oceans: continental drift and the origins of oceans
Oceanography: Oceans

Waves: theory and principles of waves, how they work and what causes them
Oceanography: waves

Special Waves
Oceanography: waves

... much, much more ...
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Old 01-11-2008, 13:40   #6
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Very interesting - thanks for sharing.
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Old 01-11-2008, 13:52   #7
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Ocean acidification?? Does the bad news never end??

Wow.
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