# Tag Info

## Hot answers tagged oceanography

43

Arctic ice, around the north pole floats on top of water. When it melts it does not add to sea level rises and likewise for other ice on water, as illustrated in this video and this video. Ice on land is a different matter. Ice on Greenland, Antarctic land & glaciers around the world will add to sea level rise because any melt water will eventually end ...

33

What does it take to reduce the salinity? The salinity of sea water is around 35 g/kg. There are around 1,350,000,000 km³ of water, so roughly 1.3x1021 kg of seawater (1 kg/l, which is a bit off for saltwater of course, probably by 35 g). Which contains about 4.7x1019 kg of salt. To reduce the salinity to just 34 g/kg, you need to extract 1.4x1018 kg of salt ...

19

The residue dry powder you refer to is salt. Salt is toxic to most plants. The United Nations claims the world is already losing 2000 hectares per day of farm land to salt-induced degradation. This is land that is used to feed people. In some situations, salt from affected lands can contaminate underground sources of drinking water, which will affect people, ...

13

Because a lot of that ice is currently sitting on land. When it melts, it will go into the ocean. From the National Snow and Ice Data Center Page (NSIDC), Facts about glaciers: Presently, 10 percent of land area on Earth is covered with glacial ice, including glaciers, ice caps, and the ice sheets of Greenland and Antarctica. Glacierized areas cover over 15 ...

12

I'm not sure how much I can comment about it, but here we go (that's a joke... maybe). Is it realistic in the collapse of the current system? Well kind of, but not in the timespan that is suggested. But that was a big part of the movie. It has also been mentioned to me that in one of the points of the movie, they actually show the thermohaline circulation ...

9

The oceans are salty because the slightly acidic rainwater dissolves minerals from ores and rocks and runs into the sea. This is a continual process, a consequence of erosion. However, the salinity of the oceans has been stable for millions of years, indicating that there is an equilibrium between processes in both directions. Salt is removed from the oceans ...

6

The simple answer to this question is that cold seawater is denser than warm seawater, so it sinks and fills up the abyssal ocean. The water that fills up the abyssal ocean comes from the polar regions. Here's a 1990s plot of temperature in the Atlantic, retrieved from the WOCE Atlantic Ocean Atlas: You can see that the coldest water is coming from the ...

5

Waves travel over the ocean surface with columns of water molecules moving in a circular motion, as seen here. As you can see, when the waves reach shallow ground, the friction of the molecules over the seabed causes it to topple over and break. If in your case there is a tall obstacle under the water instead of the gradual slope, the wave energy will but ...

5

Short answer : yes Challenger Deep was discovered by (and named after) HMS Challenger in 1875. This was the world's first true oceanic scientific voyage. They took a LOT of soundings but compared to the size of the oceans they were merely lots of pin-pricks. So your doubt would have been well founded in the pre-satellite era. Nowadays bathymetry is measured ...

4

This is a statement of the kinematic free surface boundary condition: there can be no normal flow through the boundary, only tangential flow along it. Equivalently, the normal velocity (relative to the interface) of the free surface position is the same as the velocity of the fluid. Defining the position of the free surface as $$z = \eta(x,y,t)$$ then ...

4

Thanks to @Eartworm I learned today I was totally uncorrect: there are more than 2000 meters deep in the straits. Tool to see bathymetry, navionics.com

4

No it is not inevitable that the production and continued used of lithium batteries will mean the exploitation of cobalt, manganese and nickel nodules from the sea floor. Sufficient quantities of these metals are obtained from conventional land based mines. Nickel Two types of nickel mineralization are currently mined: sulphides and oxides (laterites). ...

4

The arrival of plants can only reduce the total CO2 levels because they metabolize carbon and oxygen. Plants don't make CO2 appear which wasn't there, they only absorb and release ambient CO2. Two ways that the ocean can absorb more CO2 through a higher atmosphere concentration, and through acidification of limestone which can dissolve the limestone. If an ...

4

Along the eastern US coast, the Gulf Stream travels over broad, and shallow, continental shelf. On the western edge of this shelf, friction slows the Gulf Stream as does seasonally driven local convection and surface gyres. In many places along the east coast, local currents may be reversed well beyond 1km from shore, depending on the season. Check out this ...

3

I noticed that there is a push to close the question, and I get why. But I do think that guidance towards a university is still important, even if it does not fit the Earth Science SE guidelines. So here is my answer (as someone who does not study oceanography, rather as a meteorologist): It depends. What I have found is that the question you should ask is ...

3

There are two reasons for this surprising finding: Compaction. Once you have high pressures at depth, the less dense material goes up. Take a bucket of water, put sand in it, and squeeze the sand really hard. Water goes up. Then, you'd expect no water at depth of several kilometres. Even if you somehow had free water at these depths, the expectation is that ...

3

The Arctic has already been explored extensively by people traversing over the ice, by air and by naval submarines. On August 3, 1958, the American submarine USS Nautilus (SSN-571) reached the North Pole without surfacing. It then proceeded to travel under the entire Polar ice cap. On March 17, 1959, the USS Skate (SSN-578) surfaced on the North Pole and ...

3

The sea floor has been mapped using sonar from ships as shown here, and radar. But the fact was first discovered long before these technologies existed by sailors who got stuck in the ice. The entire ice sheet is floating and spinning at a relatively high rate of speed. When they got stuck, they could see, from the stars, that they were moving. I cannot find ...

3

The outer banks are, literally, a textbook example of what are known as Barrier Islands. They are thought to be formed through interactions between sediment undergoing longshore drift, coastal currents and seabed irregularities, but to spite a number of theories being put forward since the 19th Century we really don't understand their formation. We do know ...

3

It is not hard to do this calculation if you have global topography. Using a version with $\frac{1}{6}$- degree resolution and a sea level rise of 1027 m, the result is @Erik's value of 445 million cubic km. Here's the bit of MATLAB code: H = 1027; % sea level rise (m) topo(topo<0) = 0; % change all ocean depths to zero topo(topo>H) = H; % level ...

3

The law that governs the pressure of gas at equilibrium over a dissolved liquid is called Henry's Law. Note, the equilibrium assumption, as there is some time dependence. That is, if you start with no dissolved gas in pure water, then in a relatively short amount of time, the amount of dissolved gas will be less than equilibrium. Let's talk in abstractions. ...

3

Loss of ice mass floating in oceans has negligible contribution to sea level rise. Loss of ice mass over land does contribute to sea level rise. It is the net balance (the difference) between flow of ice and meltwater into the oceans and the amount of snowfall in the catchment that determines the overall change to a glacier's ice mass and that determines if ...

2

The semi-enclosed body of water can probably be called a reef lagoon. https://link.springer.com/referenceworkentry/10.1007%2F3-540-31060-6_202 A coral reef lagoon is that body of water that lies within an atoll (annular) reef or within a barrier reef. It is generally assumed that an appreciable depth of water is maintained within the lagoon, say 5-50 ...

2

@John has answered to the second question: "Is there a natural process which removes salt from the sea at a significant rate?" This is an answer to the first one: "Is there a natural limit to this process, or the will the sea keep getting saltier forever?" Yes, there is a limit, sea water cannot keep getting saltier forever. Sea water is ...

2

As a refresher, let's refer back to the definition of the material derivative: $$\frac{D}{Dt}=\frac{\partial}{\partial t}+u\frac{\partial}{\partial x}+v\frac{\partial}{\partial y}+w\frac{\partial}{\partial z}$$ If we apply it to $\eta$, then we get: \frac{D \eta}{Dt}=\frac{\partial \eta}{\partial t}+u\frac{\partial\eta}{\partial x}+v\frac{\partial\eta}{\...

2

You can study the many maps, it seems there is a giant ridge foming but the ice grinds it faster than it rises. Icebergs are grinding the arctic deeper than sea level, like 300/400 meters deep, also considering the glacial maxima when the sea level is lower and there is more ice, whatever mountains are rising in the arctic are weathered far below the sea ...

2

It seems that attenuation is much greater at ultrasound frequencies: 50 khz 12-15 dB/km 0.5khz 0.024 dB/km It depends on what distance and resolution you need.

2

Nothing really prevents water from existing deep inside Earth. We have direct evidence that it does, even in the mantle. Evidence for such water may be found in Ice VII inclusions in diamonds[1]. Because of their great mechanical strength, diamonds formed in the mantle retain GPa-level pressure within their lattice, so when they come to the surface and ...

2

Desalination of ocean water costs energy; beside fresh water, you gain salt. With some additional energy invested, you could purify this salt consisting to large extent of sodium chloride (NaCl) which may be used as table salt. In other places, you mine for rock salt from underground mines, and equally perform a purification of salt, yet without the ...

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