46 votes

Why doesn't the 71% water of the earth dry or evaporate?

There are two ways this problem needs to be looked at. The first is more astronomy than Earth science. The Earth as an entire system is largely contained. Its gravity and magnetic field retains ...
userLTK's user avatar
  • 5,857
39 votes

Why does the salt in the oceans not sink to the bottom?

When dissolved in water, salt breaks up into sodium and chlorine ions, which combine with water molecules so they cannot easily sink. However, there is a tendency for streams of fresh water to float ...
Michael Walsby's user avatar
38 votes

Antarctic and arctic meltwater is "bad" because it's dark, but why is transparent liquid on white stuff so dark?

Water has lowest EM absorption in the blue part of light spectrum and increases rapidly towards both UV and red parts of spectrum. As a result in visible light water is blue. Same goes for the ice ...
NotAName's user avatar
  • 689
34 votes

While desalinating ocean water, would it be bad if we didn't pump the brine back into the ocean?

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 ...
Arsenal's user avatar
  • 441
30 votes

Why does the salt in the oceans not sink to the bottom?

Why does the salt in the oceans not sink to the bottom? Because there isn't any "salt", per se, in the ocean. Salt, as the compound sodium chloride (NaCl) does not exist as a solid in the ocean. It ...
Gimelist's user avatar
  • 23.1k
28 votes

How can we have groundwater depletion when the Earth is 78% covered with oceans?

How can we still lack groundwater? That 71% of the Earth's surface is covered by oceans is completely irrelevant to the issue of fresh groundwater depletion. Salty groundwater is useless for drinking ...
David Hammen's user avatar
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26 votes
Accepted

Why are these U-shaped bodies of water frequent near Kura river?

They look like oxbow lakes. Some meander scars (crescent-shaped, but dry) are also visible. Here is an excerpt of the "OXBOW" entry in Encyclopedia of Geomorphology (2013): An abandoned ...
Jean-Marie Prival's user avatar
25 votes

Why doesn't the 71% water of the earth dry or evaporate?

Why doesn't 71% water of the earth dry or evaporate? The simple answer: Because it rains. The not so simple answer: By some estimates, the Earth has already lost about a quarter of its water, and it ...
David Hammen's user avatar
  • 23.6k
19 votes

While desalinating ocean water, would it be bad if we didn't pump the brine back into the ocean?

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 ...
Fred's user avatar
  • 24.7k
17 votes

Antarctic and arctic meltwater is "bad" because it's dark, but why is transparent liquid on white stuff so dark?

"Transparent" is not the same as "white" : white bodies reflect most of the light while transparent bodies let the light though. Once the light enters into water, it may need to travel a long way ...
Dmitry Grigoryev's user avatar
16 votes

How is it possible to use up the water in a region?

This is a really complex problem and would require a really detailed explanation about atmospheric circulation, meteorology and hydrology. The short answer to your question is that water is going ...
Nemesi's user avatar
  • 1,268
15 votes

What would be the effect of bringing seawater pipes to the Sahara desert?

This is an interesting question & I've been waiting to see what answers, if any, would be written. One affect of creating such a lake would be a localized increase in humidity in the vicinity of ...
Fred's user avatar
  • 24.7k
15 votes
Accepted

Ground water is almost every where, then how do mines and other holes are digged so that ground water doesn't drain into it

We pump it out. Open and closed pit mines usually have pumping installations to get the water out. Look up Mine dewatering on Wikipedia. There have also been numerous accidents in the past where ...
Jan Doggen's user avatar
  • 2,679
14 votes
Accepted

How is it possible to use up the water in a region?

You're making a mistake, at least for the second case: In the second case, the water ends up as rain, presumably within a few hundred kilometers of the evaporation point. You cannot model a dry ...
gerrit's user avatar
  • 11.7k
13 votes
Accepted

How much water is the atmosphere losing to space?

It is not actual water what is lost to space, because in the high atmosphere water usually dissociate into other molecules or ions. The oxygen ion outflow is frequently assumed to be a proxy for the ...
Camilo Rada's user avatar
  • 17.7k
13 votes
Accepted

Water on Mars and Earth

If water on Earth came from meteorites, why doesn't Mars have substantial water? First off, that's a conjecture regarding the origin of the Earth's water rather than a known fact. A few times a year ...
David Hammen's user avatar
  • 23.6k
11 votes

If water is a renewable resource, why is there water scarcity?

What I miss in the other answers is water quality. Even is there is sufficient water available it is often of insufficient quality for the purpose you want it for: We often don't drink straight out ...
Jan Doggen's user avatar
  • 2,679
11 votes
Accepted

Will the oceans swallow all of the land?

If no new mountains were built, yes. Ultimately the processes of erosion would render the continents flat, and the seas would be left shallow and filled with sediments. The reason that this doesn't ...
Arkenstein XII's user avatar
11 votes

Why does the salt in the oceans not sink to the bottom?

I'm a regular from the Physics Stack Exchange reporting for duty. Why this is a serious question This is a bigger question than you might be giving it credit for. The question is ultimately similar ...
CR Drost's user avatar
  • 211
10 votes

What keeps water from sinking into earth?

So what prevents that happening on earth? Not much. Quite a lot of water is recycled into the Earth's crust and mantle. So the only thing that prevents the water from sinking in is the temperature, ...
Gimelist's user avatar
  • 23.1k
10 votes
Accepted

Why does an artesian well dry slower than a normal well?

Well B is a normal water table well, which will have a relatively steep, tight, local, and deep 'cone of depression'. Well A doesn't have a 'cone of depression' - it has a 'cone of depressurization', ...
Gordon Stanger's user avatar
10 votes

Would oceans regenerate if removed?

I'm ignorant of all the organic and inorganic chemical reactions that can destroy or create water, and the factors controlling them. But I can give a shot to the part of the question related to ...
Camilo Rada's user avatar
  • 17.7k
10 votes

How do we compensate the water that is being taken out of water cycle for curing of concrete in infra construction?

The top twelve cement producing countries in 2020 produced 3191 Mt of cement. Increase this to 4000 Mt to include the rest of the world. Depending on the application, the water to cement ratio of ...
Fred's user avatar
  • 24.7k
9 votes

What would be the effect of bringing seawater pipes to the Sahara desert?

Nevada is 286,367 km² in area. With a conservative average evaporation of 2500 mm/yr in your desert, a lake of that size would evaporate 22686 m3/s. That is a flow larger than the average river ...
DrGC's user avatar
  • 1,773
9 votes
Accepted

If water is a renewable resource, why is there water scarcity?

I would summarize the main factors that can lead to water scarcity in the following points: Increase in demand: As population grows, there is more overall water consumption. The rise is enhanced by ...
Camilo Rada's user avatar
  • 17.7k
9 votes
Accepted

While desalinating ocean water, would it be bad if we didn't pump the brine back into the ocean?

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 ...
Nullius in Verba's user avatar
9 votes
Accepted

Where to find reliable water temperature?

The Met Office Hadley Centre provides global quality controlled ocean temperature and salinity profiles and monthly long-term objectively analyzed global fields with a one degree spatial resolution (...
arkaia's user avatar
  • 15.4k
9 votes
Accepted

Would covering part of Lake Mead with large sheets of bubble wrap reduce the amount of water lost to evaporation?

Something similar has been done with plastic balls. I'd guess they're much easier to manufacture, since it doesn't have to be a continuous sheet. It sounds like there is some local water savings, ...
damp_civil's user avatar
8 votes

What would be the effect of bringing seawater pipes to the Sahara desert?

I see three issues to be considered and will address them in what I think is reverse order of importance: 3) Cost: you have considered this with solar power and by trying to use mud to reduce ...
haresfur's user avatar
  • 4,419

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