Some time ago, I wrote the same in spanish, now I translate it into English, so more people will understand. I wrote that because a friend of mine asked me why the sea is salty when the rivers are not, I didn't know what to answer, so here, I'll try to explain it a good way.
When I was little, somebody told me a story about a little magic coffee grinder, which was the first explanation to the saulty taste of seawater:
Long time ago, in a fishermen village, two brothers, the little one, Nico, was really generous and humble, he fished just what he needed to eat, had old fishing gears and many days, he had no fish. His older brother, Bruno, was greedy, he managed to get rich a expenses of the others, he had the best fishing gears and the best fishing boats.
One day, after a long fishing season offshore, the little brother returned sad and hungry to harbour, because he didn't managed to fish almost nothing, and he decided to ask for help to his brother, but he just shutted the door in his face laughting at him. Even more depressed, the little fisherman returned home when a very old man, with a long white beard said to him: "I have seen all that has happened, I know that you are a good guy. I want to help you". In his hands, he had a wooden coffee grinder with a beautiful golden crank arm. Nico, incredulous, looked at the white beared man and responded: "How can a coffee grinder help me, if I have no money for the grains?" The man laughted and said: "This grinder is magic, I will tell you how it works if you promise me that you will never tell anybody, deal?". Without trusting, Nico accepted.
When I was little, somebody told me a story about a little magic coffee grinder, which was the first explanation to the saulty taste of seawater:
Long time ago, in a fishermen village, two brothers, the little one, Nico, was really generous and humble, he fished just what he needed to eat, had old fishing gears and many days, he had no fish. His older brother, Bruno, was greedy, he managed to get rich a expenses of the others, he had the best fishing gears and the best fishing boats.
One day, after a long fishing season offshore, the little brother returned sad and hungry to harbour, because he didn't managed to fish almost nothing, and he decided to ask for help to his brother, but he just shutted the door in his face laughting at him. Even more depressed, the little fisherman returned home when a very old man, with a long white beard said to him: "I have seen all that has happened, I know that you are a good guy. I want to help you". In his hands, he had a wooden coffee grinder with a beautiful golden crank arm. Nico, incredulous, looked at the white beared man and responded: "How can a coffee grinder help me, if I have no money for the grains?" The man laughted and said: "This grinder is magic, I will tell you how it works if you promise me that you will never tell anybody, deal?". Without trusting, Nico accepted.
The man explained: "if you turn the crank arm clockwise and ask for a wish, the grinder will make it real, and when you want to stop it, you just have to say these exact words <> and the grinder will stop". The old man taught Nico the performance asking for strawberry candy and gave the grinder to him. Nico was really excited and, since then, he asked the grinder to build a new house, new fishing gears, a better boat... and always, when he had enough, he stopped the coffee grinder.
His new wealth reached his evil big brother's ears, who ran to ask him how did he get them. Nico, remembering what the old man told him, didn't tell him anything.
Thus, Bruno started to spy his brother to discover his secret, and one night, Bruno saw his brother getting the grinder: "grinder, grind me some money for the fishermen who lost the ships in the storm". The next day, when Nico was distracted, Bruno got the coffee grinder and ran away, took the boat and ran offshore, somewhere to enjoy his endless riches.
His new wealth reached his evil big brother's ears, who ran to ask him how did he get them. Nico, remembering what the old man told him, didn't tell him anything.
Thus, Bruno started to spy his brother to discover his secret, and one night, Bruno saw his brother getting the grinder: "grinder, grind me some money for the fishermen who lost the ships in the storm". The next day, when Nico was distracted, Bruno got the coffee grinder and ran away, took the boat and ran offshore, somewhere to enjoy his endless riches.
One day, in the middle of the sailing, the cooker didn't have salt, and the fisherman got the grinder and said: "grinder, grind a little bit of salt". The grinder started to grind, and when he had enough, Bruno commanede: "Grinder, stop grinding, stop it", but the grinder went on and on. Bruno didn't know the words he had to use to stop the grinder, and it just continued grinding more and more money, never stopping. The miser robber said and repeated: "stop it, stop grinding, stupid grinder, I don't want more salt!" But the grinder went on and on and on...
Bit by bit, the salt started to fill the boat, first the kitchen, then the hold and there was also a lot of salt on the deck. Finally, the boat couldn't hold out the weight and sank. The coffee grinder sank with the boat without having recieved the words to stop, so, now, somewhere in the ocean, there is a magic coffee grinder grinding salt forever, making the ocean salty.
End
This story tells us more than a legend, we can make an analogy of the reality with the legend.
The coffee grinder, is represented by the rift that exthends all over the ocean bottom, during aproximately 64.000 Km. through all the principal ocean basins.
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| The magma ascends charged with "juvenil water", rich in ions that will give the sea its salty properties |
The basalt emerges through the rift coming from the mantle, in regions where the ocean crust expands in a rate of some centimeters every year.
Together with this mantle rocks, there are the juvenil waters —water that has never been in a liquid stage before—, that contains in solution most of the seawater components, among them chlorine, bromine, iodine, carbon and various trace elements(1). Another kind of juvenil water, equally salty, but with another composition, is released by vulcanos from some continental margins, as the ones surrounding the Pacific, where the seabottom seems to disapear into the deep pits.
Together with this mantle rocks, there are the juvenil waters —water that has never been in a liquid stage before—, that contains in solution most of the seawater components, among them chlorine, bromine, iodine, carbon and various trace elements(1). Another kind of juvenil water, equally salty, but with another composition, is released by vulcanos from some continental margins, as the ones surrounding the Pacific, where the seabottom seems to disapear into the deep pits.
The magic salt grinder in the seabottom imagined in that old story is not that fantastical after all. The modern explanation of why the sea is salty relies on a concept of rif and seabed expansion. In the oceanic rift, the new basaltic oceanic crust is created by the volcanic activity and the gradual movement of the sea.
The new basalt releases juvenil water and a variety of elements, including heavy metals (that incorporate in the manganese nodules) and the rare helium 3 isotop, that finally scapes to the space. In the continental border, the litospheric plate is found in subduction, creating a pit and transporting the sediments accumulated on it. The plate apparently increases the thickness during the route when the plastic basalt gains rigidity in its lower part. When it descends, the plate melts again and releases the soluble elements and ions that are thrown into the atmosphere by the vulcanos. They also mantain the sea salinity and, together with the eroded rocks from the crust, as granite, provide the material of the sediments.
The most common elements in the juvenil water are them that cannot be explained if we suppose that the dissolved solids in the seawater come from the rocks weathering in the terrestial surface. The "lost" elements, such as chlorine, iodine and bromine were once called "excess volatile" elements and where attributted to volcanic emanations only. Nowadays it is supported that juvenil water can contain almost the same proportion of chlorine thant the seawater, but is much more acid because of the hidrogen ion (H+) that has for every chloride ion (Cl-). In due course, the hidrogen ions are replaced by natrium ions (Na+), producing the common salt concentration (NaCl), that constitute more than the 90% of all the seawater salts.
(1) Seawater composition.
The new basalt releases juvenil water and a variety of elements, including heavy metals (that incorporate in the manganese nodules) and the rare helium 3 isotop, that finally scapes to the space. In the continental border, the litospheric plate is found in subduction, creating a pit and transporting the sediments accumulated on it. The plate apparently increases the thickness during the route when the plastic basalt gains rigidity in its lower part. When it descends, the plate melts again and releases the soluble elements and ions that are thrown into the atmosphere by the vulcanos. They also mantain the sea salinity and, together with the eroded rocks from the crust, as granite, provide the material of the sediments.
The most common elements in the juvenil water are them that cannot be explained if we suppose that the dissolved solids in the seawater come from the rocks weathering in the terrestial surface. The "lost" elements, such as chlorine, iodine and bromine were once called "excess volatile" elements and where attributted to volcanic emanations only. Nowadays it is supported that juvenil water can contain almost the same proportion of chlorine thant the seawater, but is much more acid because of the hidrogen ion (H+) that has for every chloride ion (Cl-). In due course, the hidrogen ions are replaced by natrium ions (Na+), producing the common salt concentration (NaCl), that constitute more than the 90% of all the seawater salts.
(1) Seawater composition.
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