
Why is the ocean salty? - tosh
https://oceanservice.noaa.gov/facts/whysalty.html
======
sundarurfriend
I like that the article begins with a tl;dr summary of

> Ocean salt primarily comes from rocks on land

Not many articles do that, but it only made reading the rest of the article
more appealing to me, not less.

~~~
combatentropy
It's called the Inverted Pyramid structure, and it's how articles are supposed
to be written. I learned it in junior high
[[https://en.wikipedia.org/wiki/Inverted_pyramid_(journalism)](https://en.wikipedia.org/wiki/Inverted_pyramid_\(journalism\))].
But yeah, it's not how many articles come today:

1\. Clickbait headline that tells you nothing. (Unfortunately this article
retains that flaw)

2\. Introduction by the author of --- the author! He had been thinking about
this topic for a long time. He had this conversation with his colleagues about
it (reproduced here). Then his editor finally challenged him to have a go at
it. So here it is!

3\. Encyclopedic history of the topic (question still unanswered).

4\. Compendium of assorted controversy and minority opinion (majority opinion
still left to be stated).

5\. The information.

6\. Return to the author, his life, what he's doing afterwards, what he has
eaten for breakfast, his favorite color, etc.

7\. Request for comments, subscribe, like, share, etc.

~~~
ghaff
>it's how articles are supposed to be written

It's how traditional straight news articles have historically been written in
large part for practical reasons. Those reasons were particularly evident for
wire service copy where the newspaper using the copy could pretty much cut off
the article at any arbitrary point to fit it into whatever hole they had in
their layout.

For feature articles and many magazine articles, there's no hard and fast
journalism rule to use inverted pyramid and never has been.

You may prefer that everything be written with inverted pyramid and that is
certainly your right--and there are often good reasons--but it's not the
"right" way to do things.

~~~
combatentropy
> for practical reasons

You really think there is no benefit to the reader?

I agree that the Inverted Pyramid is the mainstay of news and would be unfit
for a novel and even some long features like you find in New Yorker magazine.

But the problem isn't that there are too many articles written in the Inverse
Pyramid that should have been written some other way. The problem is that too
many articles that should have been written in the Inverted Pyramid aren't. If
you have problems with making judgments and using the word "should," I'm
talking about writing in the practical interests of the reader. If the reader
comes to the article for information, then the article should get to the point
as soon as possible. If the reader comes for entertainment (like a novel) then
the writing can follow some other path.

To say that the reason for the Inverted Pyramid was mainly so that syndicates
could cut the article at any point to fit the space they had is to ignore all
the benefits to the reader. The reader is presented with a large newspaper of
various articles, and he is trying to decide which ones to read and which to
skip, because he doesn't have time to read a whole newspaper from start to
finish every day. Some stories, he just wants the gist, which is why even the
headlines are supposed to present the whole story, obviously in outline. A
hurried reader can browse just the headlines and know the overall news of the
day. A less-hurried reader can read the first paragraph of some of the more
interesting stories. And so on.

Even though we don't have paper newspapers as much, we still have readers with
short attentions spans. In fact, more so.

------
ccleve
I wonder why lakes aren't salty?

It's clear why rivers and lakes that eventually empty into the ocean are
fresh. Rainwater washes the salt downstream to its ultimate destination.

But many lakes do not have an outlet that leads to the sea. Water flows in and
evaporates. Where does the salt go in that case?

Or is it possible that the article doesn't tell the full story, and that salty
rocks are confined to a limited number of areas?

~~~
ajross
Time scale. Lakes are static bodies of water for a few thousand to a million
years at a time before some flood or glacier or whatnot flushes them out to
the ocean. The ocean stores the accumulated salts of 4.7 billion years of
surface rocks.

~~~
coolso
> The ocean stores the accumulated salts of 4.7 billion years of surface
> rocks.

I've always wondered. Were the rocks really there for 4.7 billion years, or
did God create the rocks in such a way to trick scientists into believing
they've been there for 4.7 billion years?

~~~
djsumdog
Sarcasm like this doesn't typically go well here. This isn't Slashdot or
/r/atheism. Believe it or not, there are religious people of various faiths on
here, both in and out of the tech community. Statements like this don't add to
the discussion, are frivolous and sorta mock peoples' believes.

~~~
coolso
I wasn't being sarcastic, or mocking anyone's beliefs, scientific or
religious. Nor am I an atheist or got lost and think I'm on Slashdot. I was
merely putting forth a question I've always thought was intellectually
interesting, something that's supposed to be encouraged here. [1]

[1]
[https://news.ycombinator.com/newsfaq.html](https://news.ycombinator.com/newsfaq.html)

~~~
Sylos
In that case, the answer to your question is that there is no answer, that
there can never be an answer (unless God tells us) and that there does not
need to be an answer.

If God really made it so that it's impossible to tell that they are not 4.7
billion years old, then it is simply impossible to tell so, hence there can be
no answer.

And there does not need to be an answer, because if there really is no way to
tell that they are not 4.7 billion years old, then by definition there cannot
be any situation where it would make a difference. So, it's perfectly valid to
just state that they are 4.7 billion years old.

I am in fact atheist, this is the viewpoint that I have from the discussion
whether maybe our entire universe is just a computer simulation ran by some
alien race or such.

If we talk about it with the religious tangent, there's of course further
questions: Some people interpret the Bible to contain an age of the universe.
So, is that interpretation of the Bible wrong or not? And if it's not, why
would God want to trick us with those rocks? Did he create the universe some
few thousand years ago, but thought it'd be a more interesting world, if there
was some backstory to it? So, does he want us to explore this backstory? Or is
it a test of your faith in the Bible? ...which to my knowledge really doesn't
state a concrete date for creation, so at least to me that'd be strange.

------
bcaulfield
Love any science article that provides a clear, scientifically accurate answer
to any question my 6 year old asks me.

That's a lot of salt, though: "if the salt in the ocean could be removed and
spread evenly over the Earth’s land surface it would form a layer more than
500 feet thick."

~~~
al2o3cr
That sounds huge until you ponder that the water that salt is dissolved in
_is_ a layer many hundreds of feet thick covering 70% of the surface. :)

~~~
samstave
What if you took all the water out of the oceans and layered it over the land?
how thick would that water be?

~~~
belorn
Just a guess, but around 14000 feet.

If 3.5% of the water is salt and that would create 500 feet of salt if staked
on land, then the remaining 96.5% would make 13785.7 feet of water assuming
salt and water has the same density.

~~~
caseymarquis
Right order of magnitude. There's 1.33×10^9 km^3 water in the ocean. .510×10^9
km^2 surface area on the earth. .292 of the surface is land. If I did the math
right that's about 29,000 feet.

~~~
ilyagr
If your numbers are right, the quotient is about 2.7km which is 8555 feet.

~~~
caseymarquis
1.33/.51/.292 is about 8.9km. You're spreading the ocean over the surface of
the entire earth instead of just the continents. Average ocean depth is 12,000
feet, and there's less land than ocean, so the answer must be greater than
12,000 feet.

------
Steuard
The US Geological Survey gives a slightly more nuanced answer
([https://water.usgs.gov/edu/whyoceansalty.html](https://water.usgs.gov/edu/whyoceansalty.html)),
based (as I understand it) on comparatively recent progress in understanding
this question.

It turns out that in addition to the "standard" explanation that the oceans'
salt comes from rain dissolving rocks on land, another quite important
contributing factor is the activity of hydrothermal vents on the ocean floor.
As I understand it, the high temperature of the water emerging there helps it
to carry very large amounts of dissolved minerals from deep in the crust back
into the sea (and that our models of ocean salinity wouldn't work without this
contribution).

------
dzhiurgis
What I find fascinating is how in fact we are dependent on Natrium
([https://www.youtube.com/watch?v=J3HivpHP-5I](https://www.youtube.com/watch?v=J3HivpHP-5I)),
presumably because our organisms originated from oceans to begin with.

Yet still, if dominating salt were Lithium or Potassium, we'd still probably
happen to evolve, yet with slightly different cellular features.

~~~
Someone
Interesting that you say Natrium (as opposed to Sodium), but Potassium, not
Kalium. I thought use of the two variant names for those elements was 100%
correlated. Are there regions of the world where that is not the case?

~~~
dzhiurgis
I just screwed up at being smartass :)

It is Kalium here too, but I did heard Potash before when referring to a
mineral or fertiliser.

------
cordite
Supposing a terraforming species (like humans) never arose, will the ocean get
saltier and saltier over the eons and eventually be inhospitable to all but
the hardiest of microbes?

~~~
labster
IANAG, but you're not accounting for processes that remove salt from the
ocean. All of our salt mines come from somewhere -- crust that's been elevated
to make an inland sea, that gradually evaporates and leaves a salt deposit.
This can then get buried.

Possibly when the tectonic processes stop on Earth, the oceans will continue
to get salty from weathering of rocks. And you won't have much addition of
water from volcanism, only a little bit from space. But life gets generally
hard without active tectonics anyway.

------
b34r
It’s completely breathtaking how massive our planet is in every measure that
matters. And then we find out how big Jupiter is, VY Canis Majoris... The
universe is a wonderful place!

~~~
Splines
I've often wondered what living on a earth-like planet as large as Jupiter
would be like. People on the other side of this "planet" would be aliens to
you.

~~~
ekianjo
Nice thought but earth like planets can never get that big because of gravity.

~~~
danieltillett
A rocky planet the size of jupiter is not physically impossible. It is almost
certainly incompatible with life, but there is nothing in the laws of physics
that would cause such a sized planet to explode or collapse.

~~~
craftyguy
It would not explode or collapse, but it would almost certainly be molten
liquid and/or gaseous rock for a very, very long time

~~~
danieltillett
Yes that is why I said it is unlikely to be compatible with life.

It would almost certainly be molten at the surface with no water no matter the
distance from the star due to radioactive decay.

------
based2
[https://science.nasa.gov/earth-
science/oceanography/physical...](https://science.nasa.gov/earth-
science/oceanography/physical-ocean/salinity)

[https://en.wikipedia.org/wiki/Soil_Moisture_and_Ocean_Salini...](https://en.wikipedia.org/wiki/Soil_Moisture_and_Ocean_Salinity)

------
__s
This made me wonder towards if the ocean is therefore becoming saltier & if
so, at what pace? Found: [https://www.seeker.com/are-the-oceans-getting-
saltier-176509...](https://www.seeker.com/are-the-oceans-getting-
saltier-1765098598.html)

~~~
cryptonector
The oceans are not saturated with salt, and there aren't many processes that
extract salt from the ocean, but the process that made the oceans salty to
begin with continues.

Also, the Earth is slowly losing its atmosphere, and with it -presumably- some
water.

Of course, there's still a lot of water in rocks, so it's possible that the
oceans could gain water and thus less salty.

But my guess is it's getting saltier.

~~~
ijidak
Any idea about this line from the seeker article above?

> "Salt ions themselves aren't added or removed from the ocean, but water
> molecules are freely gained or lost through the processes of evaporation and
> precipitation, or freezing and melting of ice," said Ruth Curry, a senior
> research specialist at the Woods Hole Oceanographic Institution.

 _" Salt ions aren't added"_. That doesn't seem right...

~~~
throwaway5752
Woods Hole is a fine research institution. I think you can assume they were
trying to make the concept accessible to layman.

And I think they are trying to not get into all the complexities (yes, Na+ and
Cl- ions are added/removed in some natural processes, but many times less
readily than water). One could easily point tectonic processes and salt loss
via evaporite layer deposition, but you don't lose a lot by not going into the
weeds.

------
qwerty456127
> By some estimates, if the salt in the ocean could be removed and spread
> evenly over the Earth’s land surface it would form a layer more than 500
> feet thick, about the height of a 40-story office building.

Needless to say [almost] every land plant and creature on Earth would die in
such an event. I just wonder (out of pure bizarre curiosity) what would happen
if the salt in the ocean could be removed and put somewhere in the outer space
- what part of the ocean life would survive and how much impact would it have
on the land life.

~~~
baddox
I’d be curious to know how much energy would be required to separate all that
salt from that water, especially in terms of the total solar energy Earth
receives. If, hypothetically, all that solar energy were devoted to
desalinization, how long would it take?

------
fauigerzigerk
What I'm wondering is why humans can't drink the water from the most
ubuquitous reservoir on earth.

~~~
lists
Because we come from the middle of Africa

~~~
fauigerzigerk
That was hundereds of thousands of years ago and we (well, many of us) have
adapted to drinking milk (as adults) during that time.

So even though much of the planet is covered with sea water very few mammals
have developed the ability to use sea water for hydration. I just find that
surprising.

~~~
thenewwazoo
Processing milk is a digestive change, and one that mammals are all able to do
at some point. It’s not a very far leap. Processing water with the sea’s
salinity would require changes to how our cells are constructed, or at least
would require massive changes to our kidneys. There’s simply no (or not
enough) selection advantage for it to have happened.

------
hansthehorse
Posing this question to a young earth, christian, literal bible believer will
generate interesting conversations.

~~~
PhasmaFelis
I strongly suspect that it won't.

------
foota
Is ocean salt equilibrium?

------
del_operator
I'd be salty too if I had such a rocky interaction with the world.

