What causes underwater current?

[the_cat_keeper]

Hi... what causes underwater current and why do some go upwards and some downwards?

Just curious,
Cat.

 

[Zippsy]

http://seawifs.gsfc.nasa.gov/OCEAN_PLANET/HTML/oceanography_currents_1.html

Mainly differences in teperature and salinity.

 

[Marek K]

And, on the global scale, the Coriolis effect?

 

[Diver0001]

Hi... what causes underwater current

Hmmm..... The water?



Just kidding. Aside from what Zippsy already posted, the tides are an important source of current. There are probably lots of sites you can look at for information about tides but this is one I know: www.getij.nl. Just click on the english flag in the top and then read the bit about tides and tidal prediction.

R..

 

[Rick Murchison]

Wind (& waves), tide, temperature differences, interaction with the bottom, river outflow, occasionally seismic events. (the coriolis effect helps determine the direction of the currents caused by these factors)
For divers most upwellings and downwellings we encounter are associated with current moving across bottom with vertical relief. A current flowing from the shallow to the deep side of a wall will create a downwelling; a current flowing from the abyss to the shallow reef will cause an upwelling along the wall.
Rick

 

[donacheson]

Wind (& waves), tide, temperature differences, interaction with the bottom, river outflow, occasionally seismic events. (the coriolis effect helps determine the direction of the currents caused by these factors)
For divers most upwellings and downwellings we encounter are associated with current moving across bottom with vertical relief. A current flowing from the shallow to the deep side of a wall will create a downwelling; a current flowing from the abyss to the shallow reef will cause an upwelling along the wall.
Rick

A pretty comprehensive response.

"Density differences" is more inclusive than "temperature differences" since it also includes salinity differences. Also, the the last sentence, "may" is more accurate than "will".

I know: picky, picky. <G>

 

[Jim Lapenta]

Gnomes. They push and pull real big rods and cause the currents.

 

[Kim]

Gnomes.

Damn! I thought it was Mermaids.