Questions tagged [water]

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40
votes
10answers
25k views

Why is the pond in my backyard not frozen when it is -15 °C (5 °F) outside?

I am in O'Fallon, Missouri and today it is -15 °C (5 °F) outside. I was taught water freezes at 0 °C (32 °F). I could understand if it was exactly 0 °C (32 °F) that the water might not be turning to ...
34
votes
3answers
2k views

How would plate tectonics differ if Earth had no water?

Water plays a crucial role in plate tectonics by easing the brittle and ductile deformation of the Earth's lithosphere. Water lowers the Mohr-Coulomb for brittle fractures. During ductile deformation, ...
30
votes
4answers
35k views

Is it possible for rivers to freeze completely and stop flowing?

Is it possible for rivers to freeze completely in the winter and stop flowing? Are there known examples of this? If yes, how large can these rivers be and where does the water go? There are several ...
24
votes
7answers
25k views

Is a complete global flood physically possible on Earth?

Genesis 7:11-20 presents an account of a precipitation event which, in 40 days, submerges the entire surface of the earth: [On] the seventeenth day of the second month — on that day all the ...
23
votes
8answers
10k views

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

This is something that just occurred to me. If heavier elements sink, then how can the entire ocean be salty? Shouldn't the 'salt', because of its density, all sink to the bottom of the ocean? In ...
19
votes
1answer
1k views

What fraction of dry land is below sea level?

Someone just asked me if it would be practical to counter the rise of sea level by pumping water into storage on land. It struck me that if there is enough land below sea level, this would require ...
18
votes
6answers
14k views

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

Perhaps a simple question, we know 71% of the earth's surface contains water as oceans. If Earth's age is 4.543 billion years, then I guess it should be decreased with drying or should have been dried ...
18
votes
2answers
8k views

What does it mean for waves to “feel” the bottom?

While typically waves are said to "feel" the bottom when the depth of the water is less than half the wavelength, what does it mean for the waves to "feel"? Furthermore, why does this happen at the ...
18
votes
2answers
564 views

Is this ice cover real - and what circumstances are required to make it?

The title says it all... I assume it requires very slow freezing sheltered from the wind. Undercooled water, maybe? A Reddit thread talks about Delaunay triangulation, but that does not explain how ...
15
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4answers
10k views

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

This is a childhood dream. What would happen if pipes were installed (similar in principle to the Great Man-Made River, but for seawater) to continuously pump seawater into the Sahara desert. Let'...
15
votes
2answers
4k views

Lanes of flat ocean surface in coastal waters

When the ocean is still, i.e. there aren't waves that disturb the surface, you often see "lanes" of water that seem flat as opposed to areas where the wind causes ripples. What causes this?
13
votes
3answers
3k views

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

The Dead Sea, rivers in California and the Aral Sea are said to be shrinking due to water usage, e.g. for agriculture. Yet the water must go somewhere. After the fields are irrigated, the water ...
13
votes
3answers
11k views

Would oceans regenerate if removed?

On Earth, there is enough Hydrogen and Oxygen to make 13,88 million km$^3$ of water (calculation below). However, oceans contain only a tenth of that. Clearly, most of the hydrogen must be stored in ...
13
votes
1answer
534 views

Where does the water from rain in rain forests come from?

When discussing a hypothetical world without oceans and just forest it occured to me that I wasn't so sure there would be any rain in the first place, due to the lack of oceans. Searching on Google ...
12
votes
2answers
10k views

Water veins underground causing health problems

It seems to be given that around my country everybody believes in water veins (that's the best that Google Translate could come up with. Basically underground water currents) that somehow affect ...
12
votes
1answer
243 views

How different is the proportion of heavy water ($\ce{^2H2O}$) in the different oceans?

The average proportion of naturally occurring semi-heavy water or deuterated water, $\ce{^2HHO}$ or $\ce{HDO}$, is about 1 molecule in 3200. The proportion comes from the fact that one hydrogen in ...
11
votes
6answers
4k views

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

Water is a renewable resource, renewed by the water cycle. If we use water too quickly, water should get evaporated and come down again as precipitation. So, Why is there water scarcity if water ...
11
votes
2answers
158 views

Water on Mars and Earth

If water on Earth came from meteorites, why doesn't Mars have substantial water? What made it more highly probable on Earth than on Mars?
11
votes
2answers
176 views

What ice phenomenon are we seeing in this video?

I don't know what this YouTube video shows, but it appears to be half glacier and half "the blob." It almost appears to be "growing" although I assume it's being pushed somehow. Can someone tell me ...
11
votes
2answers
192 views

Waves on sandy beach separating differently-sized rocks?

I recently went to a beach, and I noticed that the sand seemed to have a few distinct regions. I'm wondering what would cause this, and how it works. One region is the part of the beach which is ...
11
votes
0answers
127 views

Using sodium chloride load as a point source pollutant variable in SWAT model?

I'm currently working with the Soil & Water Assessment Tool (SWAT). My task is to model the loading of sodium chloride into streams. One approach I would like to take is to use the point ...
10
votes
3answers
376 views

Will the oceans swallow all of the land?

I am wondering why, since the oceans could feasibly hold all of the dry land, they in fact do not. For example, the Mariana Trench drops to -10.9km, while Mount Everest only reaches to +8.8km. ...
10
votes
2answers
577 views

How much land does it take to support New York City?

New York City has about 8.5 million people living in an area of 300 square miles which gives a population density of 28,300 people per square mile. The food required to support such a high population ...
10
votes
1answer
172 views

Sudden Localized Surface Water Temperature Increase In Eastern Lake Superior, Canada

As can be seen in the below sequence of NOAA images spanning 15 hours (most recent at top), in extreme eastern Lake Superior the surface water (but not bottom water) temperature increased dramatically ...
10
votes
1answer
859 views

How does evapotranspiration affect rainfall?

Evapotranspiration is when a plant evaporates water off the surface of its leaves in order to move water throughout its system with cohesive and adheisiveforces. My question is how will a sudden ...
9
votes
6answers
5k views

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

Why does depletion of underground water levels happening, if the Earth is covered by nearly 78% water, and there is also water in rivers and lakes? How can we still lack groundwater?
9
votes
1answer
646 views

How much water is the atmosphere losing to space?

Up until recently, I was under a (wrong) impression that the amount of planetary cumulative water resources was finite as I believed its escape from the atmosphere was impossible. I believed that, ...
9
votes
1answer
4k views

What is the temperature of the flowing water in icy river?

Boundaries of the question: The question is about rivers where water flows in cold area of the earth. Whether it's because of the winter or it's simply cold all year long. Usually, the top layer of ...
9
votes
1answer
149 views

In -20 °C weather, creeks below waterfalls here form ice columns. What are these called? Ice-canoes?

I would like to know the name(s) of this ice formation. How common or rare is it? What other regions of the world does this occur in? What specific requirements are needed to produce it and could it ...
8
votes
2answers
950 views

Was the filling of the Three Gorges Dam's impact on the Earth's rotation rate detectable?

I'm a big fan of Vsauce and the video How Earth Moves is just one example of science related to the Earth available there (there's plenty more). But the statement in this video starting at ...
8
votes
1answer
113 views

Is water actually blue or is it transparent?

This is my first post on StackExchange and I would like to ask a question: Is water actually blue or is that just the reflection of the sky?
8
votes
3answers
700 views

Why is my pond / lake melting when the temperature is still far below freezing?

I recently moved into a new house with a 2 acre lake behind it. We’ve had 15 consecutive days below freezing, and the last 12 of those have been below 20 degrees (Fahrenheit)! Six days ago I shoveled ...
7
votes
2answers
1k views

How old is Earth's groundwater?

In my house, we drink the groundwater that we get from our well. It is 40 meters deep. The question is, how old is the water that we drink today? Is it from the rain 100 years ago? Another issue is, ...
7
votes
1answer
89 views

Is salt accumulating over time?

The rainfall leaches salts (Mg,Na,Ca,K,.., Cl) from weathering rocks, where those ions were freed from chemical bonds by sunlight, acidic water etc. The runoff eventually goes into the oceans, where ...
7
votes
1answer
118 views

How much water does a wave transport into a sea cave?

How much water is transported (volume) as a wave travels into a sea cave? The wave has a height of 1 m and a period of 12 seconds. The average water depth at the cave mouth it 5 m and the width is 15 ...
7
votes
1answer
3k views

Lake Manasarovar v.s. Lake Rakshastal: fresh-water v.s. salt-water

In Tibetan Plateau, about 4600m elevation, If Lake Manasarovar and Lake Rakshastal ("lake of the demon" ) used to be the same lake, but due to the tectonic activity now they are separated to two by ...
7
votes
2answers
180 views

Does Earth risk losing its oceans to space due to global warming?

I read that we are facing the very real possibility of Earth's average temperature rising by more that 2 degrees Celsius by the end of the century. As I understand our planet is constantly loosing ...
6
votes
2answers
2k views

How would the Earth look without water in the oceans?

Has there ever been a movie, a documentary, or an image that provides a visualization of the oceans without water? I'm writing an article on geology and I thought a visual representation would be of ...
6
votes
1answer
250 views

What would happen if the same soil received waste water contaminants for a long time?

I know that soil is used to filter septic systems within our treatment system, however what happens to this soil that is used in filtration, I know it would be changed every once in a while but what ...
6
votes
2answers
96 views

Aren't fresh water deposits renewed by water cycle?

I have recently watched "How Many People Can Live on Planet Earth?" documentary with David Attenborough. In it, in the main factors that will limit total human population Earth can support the limited ...
6
votes
1answer
69 views

Is the giant impact hypothesis still alive?

It used to be thought that the unusual amount of water on our planet was the result of a giant collision between proto-Earth and a dwarf planet or planetoid called Theia. I recently heard of some ...
6
votes
0answers
435 views

How much of Earth's surface would be covered by water if all ice melted? [duplicate]

I'm trying to find how much water would be on the surface of Earth and how much surface would it cover (how much land will remain) if all the ice at the North and South Poles (and everywhere else) ...
5
votes
2answers
2k views

What keeps water from sinking into earth?

I remember reading somewhere that there's evidence of water on Mars but it all sank into the Martian soil. So what prevents that happening on earth? Some people say it's because the crust is not ...
5
votes
1answer
69 views

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

Water finds it way to the lowest point because of gravity. So if we dig a mine or something same, then how we take ground water in account, so that it doesn't fill in.
5
votes
3answers
88 views

Transferring water using underground channel

I heard in tv show, there are water channels in underground like rivers or small channels! So I just wondered why don't we use such underground water channels to recharge the underground water of one ...
5
votes
2answers
161 views

Calculate flow rate of wetland for gray water treatment

I'm currently attempting to design a water recycling solution for a carwash in a tropical country that currently uses up to 30m$^3$ (8,000 gallons US) of water in 12 hours. Based on my research in ...
5
votes
2answers
10k views

How much time does water takes to reach to the ground?

I want to understand the phenomena where water droplets after precipitation reaches to the ground. How much time does it take to become ground water or in other words how much time is taken by water ...
5
votes
1answer
137 views

Judging wind speed based on flags and inland-water observations

About a year ago, I took this video along the Hudson river in NY, and I'm trying to figure out the Beaufort number based on the water and the flags. https://www.youtube.com/watch?v=nqjvTALRWW8 The ...
5
votes
2answers
3k views

What is (negative) wind stress curl?

I'm currently doing research for a paper in school where we need to research on a university-like level. When I read the paper Causes and impacts of the 2014 warm anomaly in the NE Pacific, I found ...
5
votes
1answer
61 views

How can flood inundation vary at the same river stage?

I've always thought that river flooding would always be the same at the same river stage. For example, if the river stage is at 20' flooding at location "x" would always be at the same depth. ...