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| Gulf of alaska |
The border between the Pacific and Atlantic oceans is like a line between 2 worlds. It looks as if the two oceans meet at an invisible wall which does not let them flow into each other and mix their waters. Why on Earth does it happen? We know for sure there is no invisible wall inside, and water is water. What could interfere with its mixing? The thing is that water can be different too.
The Atlantic and the Pacific oceans have differentdensity and chemical make-up, the level of salinity and other qualities. One can see by their color that they are farfrom being the same. The borders between two bodies of water withdifferent physical and biological characteristics are known as ocean clines. Haloclines – borders between waters withdifferent salinity – are the most spectacular, and this is what we see when the Atlanticand the Pacific oceans meet. The famous explorer Jacques Cousteau foundthis when he was deep diving in the Strait of Gibraltar.
The layers of water with different salinitylooked like they were divided with a transparent film, and each layer had its own flora andfauna. Haloclines appear when water in one oceanor sea is at least 5 times saltier than in the other. You can create a halocline at home if youpour some seawater or colored salty water in a glass and then add some fresh water ontop of it. The only difference is that your haloclinewill be horizontal, and ocean haloclines are vertical. If you remember a couple of basic things fromphysics you might argue that a denser liquid should finally end up lower and less densehigher. If that were true the border between the twooceans would look not like a vertical line but as a horizontal one, and the differencebetween their salinity would become less obvious the closer they got to each other. So why doesn’t it happen here? Well, first, the difference in density ofwater of the two oceans is not that great for one of them to get down and the otherto rise up. And yet it’s enough not to let them mix. Still, another reason is inertia.
One of the inertial forces known as Coriolisforce influences objects when they are moving in the system of axes which, in its turn,is moving too. In simpler words, the Earth is moving, andall the moving objects on it will be acted upon by Coriolis force, deviating from theircourse. As a result, the objects on the Earth surfacedon’t move straight on but deviate in clockwise order in the Northern hemisphere and counterclockwisein the Southern. But the Earth is moving slowly, it takes theplanet a whole day to make a full circle around its axis. That’s why the Coriolis effect gets obviousonly in long time intervals: with cyclones or ocean flows. And this is why the direction of flows inthe Atlantic and Pacific oceans is different. It also doesn’t let them mix. Another important difference between the twooceans' water is the strength of molecules' connection, or surface tensile strength. Thanks to this strength, molecules of a matterhold to each other. The two oceans have a totally different surfacetensile strength, and it also doesn’t let them mix. Maybe they could gradually start mixing withtime, but as the flows in them have opposite directions, they just don’t have time todo this.
We think that it’s just water in both oceans,but its separate molecules meet for just a short moment and then get carried away withthe ocean flow. Don’t you think, though, that only the Atlanticand Pacific oceans don’t get on well with each other! There are a lot of places on the planet wherewater in the two seas or rivers does not mix. There are also thermoclines – borders betweenwater of different temperatures, like the warm water of Gulf Stream and much colderNorth Atlantic Ocean. Chemoclines are the most amazing ones. These are borders between waters having differentmicroclimate and chemical make-up. The Sargasso Sea is the biggest and most widelyknown chemocline. It is a sea within the Atlantic Ocean whichhas no shores but you’ve got no chance not to notice it. Let’s have a look at other most spectacularclines on the planet.
1. The North and Baltic Seas These two seas meet near the Danish city ofSkagen. The water in them does not mix because ofdifferent density. Sometimes you can see the waves of the 2 seasclash into each other, making foam. And yet their water mixes gradually, that’swhy the Baltic Sea is slightly saline. If there had been no water coming to it fromthe North Sea it would’ve been a huge freshwater lake.
2. The Mediterranean Sea and the Atlantic Ocean. They meet at the Strait of Gibraltar and havea different density and salinity, so their water does not mix too.
3. The Caribbean Sea and the Atlantic OceanThe place where they meet is near the Antilles and looks like someone has painted water withdifferent shades of blue. Another place where these two meet is theEleuthera Island of Bahamas. The Caribbean seawater is turquoise and theAtlantic Ocean water is dark blue.
4. The Surinam River and the Atlantic Ocean meetnear Paramaribo in South America.
5. The Uruguay River and its affluxThese two meet in Misiones province in Argentina. One of them is cleaned to be used in agriculture,and the other gets almost red because of loam during rainy seasons.
6. The Rio Negro and Solimões Rivers (part ofthe Amazon River) 6 miles from Manaus in Brazil, Rio Negro andSolimoes rivers low into each other but don’t mix for about 2.5 miles. The Rio Negro is dark and Solimoes – light,they have a different temperature and speed of flow.
7. Mosel and RheinThey meet in Koblenz, Germany. Rheine has lighter water and Mosel – darker.
8. Ilz, Danube, and InnThe junction of these 3 rivers is in Passau, Germany. Ilz is a small mountain river to the left,the Danube is in the middle, and Inn is the light river to the right. Inn is wider than the Danube here but stillis its afflux.
9. Alaknanda and Bhagirathi Rivers meet in India. Alaknanda is dark and Bhagirathi is light.
10. Irtysh and Ulba flow into each other in Kazakhstannear the city whose name you’ll never be able to pronounce, nor will I. You give it a shot. (Ust'-Kamenogorsk.) The Irtysh has clean water and Ulba – cloudy.
11. The Jialing and Yangtze Rivers meet in Chongqing,China. The Jialing is clean and the Yangtze is brown.
12. Irtysh and OmThese two rivers flow into each other in Omsk, Russia. The Irtysh is cloudy and the Om – pure andtransparent.
13. Chuya and Katun rivers meet in the Altai Republic,Russia. The water of the Chuya has an unusual cloudywhite color here and looks dense and thick. Katun is clean and turquoise. Flowing into each other they form a singletwo-colored flow that does not mix for some time.
14. The Green and Colorado riversThe place of their junction is Canyonlands National Park in Utah, USA. Colorado is brown and Green is – yep, green. The corridors of these rivers go through rockswith different chemical make-up, that’s why they have such a big contrast of colors.
15. The Rhone and Arve riversThey flow into each other in Geneva, Switzerland. The Rhone is a pure river that flows out ofthe lake of Geneva, the Arve is cloudy as it gets its water from glaciers of the Chamonixvalley. So, water you think about all this water? Of course it’s a bad joke, like a lot ofmy bad pronunciations of those river names.