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brunel
743693.  Thu Sep 16, 2010 6:39 am Reply with quote

Spud McLaren wrote:
Zebra57 wrote:
Spud wrote "No rivers run uphill", while this is basically true there are situations when the impossible occurs.

Between December 1811and February 1812 the massive New Madrid Earthquakes were reported to have reversed the flow of the River Mississippi.
But that's running backwards, or (more accurately) in the opposite direction from that which it normally takes - not "uphill". The lie of the land altered. The water still flowed from one location to a slightly lower one, it's just that the slightly lower one was formerly the slightly higher one. In fact

"There were temporary river waterfalls where the Mississippi ran backwards during 1811-12 earthquakes. It happened early on Feb. 7, 1812, when a thrust fault created a sudden dam several feet high in the bottom of the river loop near New Madrid.

The main section involved was from island 10 northward about 10 miles to island 8. It lasted for a few hours, though the new dams/waterfalls lasted for a few DAYS, and ruined several flatboats."

from http://showme.net/~fkeller/quake/mississippi_river_ran_backward.htm


In effect, a dam was suddenly created and the water backed up. That's completely different from defying gravity and flowing uphill. You can get water to flow uphill, but either by use of specific additives, or under lab conditions.


I've heard that the Amazon river does actually flow uphill towards the end of the river. In this particular section, the increase in elevation is very small - perhaps one or two metres in every thousand - but, because the amount of water flowing in the river is so large, the effects of the Coriolis force outweigh that of the effects of gravity, and force the flow uphill.
I am afraid that, at the moment, I have been unable to substantiate the claim, nor been able to prove that it would be possible.

 
PDR
743710.  Thu Sep 16, 2010 7:56 am Reply with quote

I think you're refering to the "Casiquiare"(sp?) which from memory is a natural canal that links the Amazon with another river (my brain says it's the Orinoco, but it has been increasingly error-prone over the last few years so don't quote me on it).

IIRC there is something rather strange about the Casiquiare in the way it appears to cross the dividing feature between two drainage systems (which should involve water effectively flowing up hill, but I can't remember the details).

But I'm not sure that Coriolis has anything to do with it - coriolis force force is a "fictitious" force and so should be confined to Booker Prize submissions and expense claims...

:0)

PDR

 
brunel
743734.  Thu Sep 16, 2010 8:52 am Reply with quote

PDR wrote:
I think you're refering to the "Casiquiare"(sp?) which from memory is a natural canal that links the Amazon with another river (my brain says it's the Orinoco, but it has been increasingly error-prone over the last few years so don't quote me on it).

IIRC there is something rather strange about the Casiquiare in the way it appears to cross the dividing feature between two drainage systems (which should involve water effectively flowing up hill, but I can't remember the details).

But I'm not sure that Coriolis has anything to do with it - coriolis force force is a "fictitious" force and so should be confined to Booker Prize submissions and expense claims...

:0)

PDR

Fair enough - I only reported the anecdote as it was given to me at the time, and because of other commitments, I had never got round to researching the comment to see if it was true.

 
Jaster
767531.  Thu Dec 16, 2010 9:34 am Reply with quote

How about the Onyx River in Antarctica ?

It flows inland not towards the sea
It's dry most of the time
Sometimes it does not reach it's outflow in Lake Vanda (which has no outflow)
It's only fed by meltwater not rain/snowfall since it is in Wright Valley a dry valley where it has not rained for at least a few thousand years ...

 

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