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From: Ken James (no email)
Date: Tue Jun 06 2006 - 21:30:02 EDT
World-Cruising (replacing spammed group)Rubber duckies float on the surface. They're much more affected by wind
currents. Any study of where they go will be a study of the surface effects
of wind.
Besides rubber ducks there were many other articles. Studies are able to tease out the wind components to a large degree or to include them. So they can get effects from sea currents, sea currents with wind induced sea currents included, and sea currents with wind induced currents and also wind drift.
As far as where will containers go "if they float long enough, as
some will" - well, there's no empirical data to support that statement, is
there?
Yes there is. Again studies have been done where containers of a known cargo and shipper were washed over the side at a known location, and were found at various times and places later. In fact there are ongoing studies about that.
And in fact, it is not at all uncommon for containers to wash ashore.
As far as subs activaly maintaining depth, sure, but if they was no one aboard and no change in density of the sub other than caused by temp changes etc., and it was barely submerged, it would stay that way potentialy for a very long time.
Whales? Yes, in fact there have been many recent studies on this subject because it is thought that the anarobic sulfar loving 'bugs' that inhabit deap sea hydro thermal vents leap frog from them to dead whales to more vents, so they needed to study dead whales...turns out there is a dead whale in the Pacific about every 5nm!
And sure the depth changes. Nonetheless they can in fact stay just below the surface for weeks.
Balloons will in fact go as high as they can still expand enough to be lighter than the surrounding air and still lift the envelope. When those become in balance it stops.
With a simple toy helium balloon they seldom get over about 30 K ft.
You keep sayinjg that stuff in the ocean will either sink all the way to the botttom or float on the surface.
OK, let me give you a counter example...it floats less. OK with that? It is on the surfacxe but flating less.
It is leaking very, very slowly. After a week or so it floats even less. Another few weeks and it is barely floating. What next? It floats less. It is now one inche beneath the surface. And next week? Four inches. And so on.
Yes, at some point, it may, often will, suddenly de-stabilze and sink quickly, but it is quite possible for an object to stay 'floating' just below the surface for quite some time.
Logs are a famous example of that. They can stay just below the surface for weeks or months in some cases.
I'd suggest you research Archimedes Principle, which speaks to buoyancy.
Nothing "floats" beneath the surface.
Nothing in that says an object cannot float beneath the surface. In fact, quite the opposite. According to the princple invoked, an object floats at a depth where its density matches the displaced water at that depth.
A sub can maintain netrual buyancy at any depth with no intervention unless condititons change.
Now if you want to say that it may do so, but not for a very long time due to changing circumstances, you may or may not have a valid point...
If an object is floating on the surface of the ocean, and it is a ridgid object, and can take on just enough extra water to change its density enough to sink just a few feet, it should be able to stay there. Why? Because as you go deeper the water gets denser but our object is not getting any denser. Therefore it will float just below the surface.
Can you provide links?
Here is another; http://www.islandnet.com/~see/weather/elements/shoes.htm
Only some of _my_ numbers were hypothetical. It is a *fact* that thousands of containers were lost overboard during this reporting time, and a *fact* that MORE than 5% (at least from some observed spills) were reported floating for a long time. So my *estimate* was most likely conserveative.
Of course, I do admit that good data is hard to come by in this area. However, I repeat, that many, many are the reports, some from well known sailors, who definatly had a collsion with a submerged object, sometimes a verified container. The risk is indeed slight if taken by just the number of containers, but the reason I feel it is a valid concern, again, is because there is no way to relably detect them at all. The best you can do is prepare beforhand for a collision with one.
So in sum, while I agree that the number of semi submerged containers as opposed to the number of other objects (big ships) is small, the risk from containers is greatly magnified by not being able to detect them. I think this is a reasoned and valid point of view and have seen nothing to sissuade me from that point of view.-Ken
[Non-text portions of this message have been removed]
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