Comments on: Earth Ocean Currents

By: Chuck Clark

Chuck Clark — Wed, 27 Jan 2010 23:42:36 +0000

Well, I’m no expert on anything but mapping, but I doubt anything like what happened to the Egyptians (surely you mean the ancient Egyptians?) is in the cards for the whole world. There’ll be more earthquakes in Indonesia, as well as everywhere else, I think everyone but nutjobs will agree with that, but in my opinion you really don’t have to worry about “the plate rising more and restricting . . . [ocean current] flow through there.” My most informed sources tell me (they’re a minority view, but that’s usually the case with the arrow of knowledge) that the disposition of continents is pretty much the same now and into the future as it’s been for a good long time, say the last billion years or so. Best steer I can give you is to look beyond the plate tectonics paradigm for some more overarching theory — see what you can come up with. Sea-floor spreading is really happening, but the other end of the cycle — trench subduction and the so-called Wilson Cycle — are being contradicted by experiment. Drop in here http://www.ncgt.org/ and look around.

And in any event the currents ain’t gonna stop. If they get blocked up somewhere they’ll just reorganize. Me, I’m a lot more worried about the antarctic ice sheet suffering a nudge toward the coast. If it ever gets started moving, it’s not stopping ’til it’s in the sea.

By: james kennedy

james kennedy — Wed, 27 Jan 2010 21:55:28 +0000

hi, just wondering, if there is more earthquakes in indonisia and the the plate rises more and restricts the warm flow through there, will all the currents stop, and cause a worldwide drought. like what happened to the egyptians.

By: Emil Petruncio

Emil Petruncio — Fri, 08 Jan 2010 13:11:23 +0000

There is a surface current which flows northward along the east coast of New Zealand (see http://www.teara.govt.nz/en/ocean-currents-and-tides/1/1 ). It does not appear on the map which NASA adapted from the American Meteorological Society, probably because that map is simply an attempt to show the major ocean currents and the gyres in the ocean basins. The flow along New Zealand could be viewed as contributing to the southern portion of the gyre which flows around the southern Pacific Ocean.

By: Chuck Clark

Chuck Clark — Thu, 07 Jan 2010 21:01:14 +0000

Robert, the north-moving surface current to the east of New Zealand, not apparent on the Emil-link map, is taken from the National Geo map. It is not an artifact of the projection, so a discrepancy. Any experts out there who’ll straighten this out?

By: Robert Tulip

Robert Tulip — Thu, 07 Jan 2010 20:50:14 +0000

Hello, thank you Emil for your comment. I agree Chuck has provided very interesting and useful views, especially by placing Antarctica at the centre of the world ocean. Another apparent discrepancy between the map at your linked site and Chuck’s map is that Chuck presents a north moving surface current in the Pacific Ocean to the east of New Zealand, but this is not apparent in your map, unless the difference is simply an artifact caused by the different projections.

By: Chuck Clark

Chuck Clark — Thu, 07 Jan 2010 19:28:42 +0000

The mapmaker stands corrected by a professor of oceanography. As for the Kuroshio Current, I've another version of these maps showing many more surface "boundary" currents (including Kuroshio). These maps (with my addition of seasonally reversing currents shown in yellow) depict the major currents as National Geographic had them. I presume because they were seeking to present global patterns amongst three levels of currents, and used that rationale to exclude major surface currents that had only localized sway. NG might have over-simplified things in order not to overwhelm a general audience. See my comment under Watersheds "M" here

By: Emil Petruncio

Emil Petruncio — Thu, 07 Jan 2010 17:39:41 +0000

These are very interesting and useful views of the ocean currents, as they help to show that we have one ocean with currents that flow through several ocean basins. However, it is incorrect to say that Earth’s rotation drives these currents. The ocean surface currents are primarily wind driven, while deeper currents flow in response to density differences. Additionally, there are oscillating tidal currents which vary in strength around the globe. Earth’s rotation *modifies* these currents by causing apparent deflections to the right in the northern hemisphere, and to the left in the southern hemisphere. Regarding the surface currents, there really ought to be a branch northward along the coast of Japan, and then eastward into the central Pacific to depict the Kuroshio Current, one of the major western boundary currents. See http://oceanmotion.org/html/background/wind-driven-surface.htm

By: Chuck Clark

Chuck Clark — Thu, 17 Dec 2009 10:44:49 +0000

Robert, Those would indeed be interesting things to know, but I am merely a mapmaker, with elaborate skill only in how the surface of the object is unfolded. All the info, like these current lines, I put on the maps is just stuff I’ve gathered from other sources. You’ll have to hunt down the oceanography experts for that sort of detail. Sorry.

By: Robert Tulip

Robert Tulip — Thu, 17 Dec 2009 09:21:51 +0000

Hi Chuck

I would be interested if you could say what the depth, speed, nutrient load and temperature are of the red, green and blue circumpolar currents around Antarctica.

Hope this is not too much trouble.

Thanks
Robert

(Please feel free to combine the two previous posts to correct the link in the first post)

By: Robert Tulip

Robert Tulip — Thu, 17 Dec 2009 09:13:16 +0000

Link actually works in the original post! it is

http://rightbasicbuilding.files.wordpress.com/2009/03/north-edged-equal-azimuth.png?w=450&h=465