The study of the physical processes and properties of the planet Earth. Applicable to many subjects about Earth, such as its shape, its magnetic field, and ocean currents.

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How is it that the Earth's atmosphere is not “blown away”?

The Earth moves at a high rate of speed around the Sun, and the solar system is moving quickly around the Milky Way. How is it that the Earth's atmosphere is not “blown away”?
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2answers
1k views

Is the total mass of Earth's atmosphere essentially constant in time?

Per a few questions and comments on this site such as Huge buildings affect earth's rotation? I wonder, is the mass of the Earth's atmosphere roughly constant? We're burning an incredible amount ...
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3answers
13k views

Can the Earth's magnetic be used to generate electricity?

Since the Earth has a magnetic field, can it, in theory, be run through a conductive metal coil to create electricity?
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2answers
409 views

What is known about the Magnetic North Pole's location before 1800?

I was recently startled to find that the Earth's North Magnetic Pole is moving at upwards of 40 km per year, with an additional ~80 km daily elliptical drift about its mean position due to variations ...
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1answer
81 views

Energy conversions, on terrestrial scale, before and during a massive Earthquake

Ethan Siegel is an astrophysicist who is now making a living as science blogger. There is a post titled: Where does an Earthquake's energy come from? Ethan Siegel points out that massive earthquake ...
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1answer
108 views

What is the Earth's magnetic field in space?

I have looked around a bit, but haven't found a simple answer. At an altitude between 100-1000 km, Is the magnetic field B still around $\sim 10^{-5}\ T$? Is there a simple equation that would provide ...
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1answer
220 views

What is the most optimal earth's axial tilt in terms of variation of seasons?

What is the most optimal earth's axial tilt in terms of variation of seasons? What would be optimal axial tilt for earth that life would exist and change of seasons would be at minimal level?
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5answers
2k views

Why the water remains on the surface of the Earth?

What makes the water stay on the surface? Why the earth does not absorb the water in it?
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1answer
141 views

Energy flows in the core also responsible for another of the planet’s unique [closed]

Energy flows in the core also responsible for another of the planet’s unique features: a strong magnetic field. Scientists believe that the earth has had a magnetic field for at least 3.5 billion ...
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2answers
350 views

Does Earth produce metallic elements in its core?

Does Earth produce metallic elements in its core?
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2answers
3k views

Where does the energy of a lightning strike go?

Lightning contains a lot of energy, so where does this energy go after lightning has hit the ground? Does it travel all the way to the core? What happens after that?
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3answers
410 views

Radio-dating and the age of the earth

I understand there are a few radio-dating methods to determine the age of the earth, uranium-lead to name one (maybe not the best though). The ratio Pb206 + Pb207 to U allows you to find when the ...
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1answer
3k views

What if the earth's core goes cold?

What effects would occur if the earth's core goes cold? Would the planet stay liveable after this happens?
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2answers
85 views

Is the altitude of the surface of the ice at the south pole determined by barometric pressure?

In one section of his auto-biography, Alvarez: Adventures of a Physicist, Luis Alvarez describes a tour of Antarctica. This comment about a flight over the south pole caught my attention: The ...
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2answers
417 views

Earth's core electric charge

Forgive my limited knowledge, but the Earth's magnetic field is created by the conductive liquid in the core and to the best I can tell organizing itself (which means separating charges?). Would this ...
2
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1answer
141 views

Magnetic field line length

If I had a magnetic bar in space that was 2cm wide and 2cm high and was one Earth diameter long and had the same magnetic strength as the Earth, would the distribution of field lines be the same ...
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2answers
491 views

Can wind blowing on smooth water create speckle interference patterns?

On a calm smooth lake, or even a large rain puddle, I've seen transient rough patches on the surface suddenly appear and disappear, and sometimes move across the water some distance before ...
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1answer
528 views

Refraction seismology - travel time for wave

I am taking an introductory class in seismology, but have some difficulties understanding the logic behind the formula used to calculate the time it takes for a refracted wave to return to the surface ...
6
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1answer
140 views

Amount of thermal energy in the Earth?

Does anyone know the amount of thermal energy that the Earth's mantle and core possess? I don't mean the maximum limit of electrical power we could generate with geothermal plants, but rather: if you ...
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1answer
113 views

What geological properties of the earth could we deduce by measuring magnetic field strength and direction?

I wonder if it is of any use for a geophysicist, if we measure the magnetic field strength and direction of the earth. Could we make valid statements about the composition of the the earth, earth ...
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0answers
61 views

Special conditions at layer F2 ionosphere

I saw this graph about the electrons density in different altitudes and difference between night and day, the difference between the 2 electron densities (day and night) decreases till 300 Km (F2 ...
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2answers
692 views

Plate tectonics and water

In a couple of places already i've read the following assertion: It is believed that plate tectonics might play an important part in maintaining the presence of water on a planet's surface one ...
6
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1answer
73 views

Is it possible to determine astronomically/astrophysically whether other planets have ever encountered polarity reversal?

We know of geomagnetic flip in Earth's history by studying geologic data. Given other planets in the system also possess a magnetic field leads to the assumption that such polarity reversal may not be ...
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1answer
224 views

Can I estimate the long-term surface heat transfer coefficient based on a temperature difference between the air surface and ground surface?

I want to estimate the long-term or annual heat transfer coefficient for the earth's surface in a particular area where the mean annual air surface temperature is about 13$^\circ$C, and the mean ...
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1answer
744 views

Refraction and Reflection Seismology

So I am wondering if I got the difference right. Both methods use explosives to send waves into the earth's surface. Now reflection seismology tries to get information from the reflected waves; the ...
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2answers
230 views

The earth's magnetic field

This might sound like a silly question. Is it possible for the earth's magnetic field to actually destroy or harm earth? (implosion, crushing etc.)
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1answer
88 views

Gravity measurements above volcanic chamber

I am trying to find out what formula to use for the above issue. If I do a gravity measurement above a volcanic chamber, what do I have to do? I thought about adding the Bouger corrections, as it is a ...
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1answer
399 views

How far does typical view of clouds/atmosphere extend?

The specific "sub questions" I'm asking are: When you are looking at clouds just on the horizon, how far away would they be? How wide (in km) is that total field of vision at roughly cloud height. ...
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2answers
852 views

Underground explosions due to plate tectonics and natural gas pockets

I am not sure if anyone has ever researched this but I am curious about underground reservoirs of natural gas and plate tectonics. Specifically, as the Earth's crust gets pulled down to the mantle do ...
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2answers
717 views

Water from Icebergs

Thousands of icebergs are calved from polar regions annually, and melt in the oceans. George Mougin, an entrepreneurial engineer, aspires to tow multi-million ton icebergs to areas of the world ...
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2answers
160 views

Would it be possible for geophysicists/geoengineers to develop an artificial way of trapping carbon in the ocean?

There's a mechanism by which the southern ocean sequesters carbon from the atmosphere. It happens when strong winds displace a large slab of surface water, accumulating in a specific region where the ...
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1answer
126 views

Ratio of horizontal to vertical kinetic energy in ocean

What is the ratio between horizontal and vertical kinetic energy in the ocean and what is the scale dependencies of this ratio ?
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1answer
467 views

How does the inner core relieve stress as the Earth's rotation slows?

One of the surprises for me in working out the answer to this question: Why is the Earth so fat? , is that the core is more elliptical than the surface, the extra ellipticity builds up gradually to ...
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2answers
201 views

What is the most energy-efficient way to crush the hardest bedrock on earth? [closed]

What is the most energy-efficient way to crush the hardest bedrock on earth while assuming it is impossible to use the chain reaction energy from that bedrock? How many energy is needed?
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1answer
310 views

What equations/constants were used to calculate the Kármán Line for Earth?

I am interested in how the original value of ~100 km was calculated for the Kármán line of earth. What equations and constants would need to be used to reproduce this value? Note: By constants, ...
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1answer
150 views

Deviation from power law distribution of earthquakes

One of the most accepted frameworks for the relationship between the magnitude and frequency of an earthquake is that of the critical phenomena. In this framework, the magnitude of events must be ...
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4answers
2k views

How do we know that earth is not perfect sphere?

I've just read here that: Equatorial radius = 6378.16 kilometers. Polar radius = 6356.78 kilometers, so the difference in circumference is 71.1 kilometers. It is not a perfect sphere, but kind ...
5
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2answers
646 views

How does Earth's interior dynamo work?

I'm interested in getting a basic physical understanding of how Earth's magnetic field is generated. I understand that it's a "dynamo" type of effect, driven by convection currents in the molten outer ...
12
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1answer
3k views

What would happen if the Earth was tidally locked with the Sun?

I'm thinking of writing a short story set on a version of Earth that is tidally locked to the Sun. I'm not exactly sure how to research the topic. Here's a number of questions about what would happen: ...
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1answer
65 views

What sets the length scale of stratified rock formations?

Driving through areas of the American Southwest such as Utah and Arizona, you notice stratified rock formations everywhere. The grand canyon is the best known example. One striking thing is that the ...
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1answer
420 views

Upper limit on the earthquake magnitude

From the Gutenberg-Richter law we know that the frequency of an earthquake is a power law, so virtually any magnitude is possible on earthquake event. But the earth has a finite size so there must be ...
2
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1answer
385 views

How much water is destroyed in photosynthesis, relative to the world's supply?

Water is involved in the photosynthesis. How much water are we talking about compared with the total amount on water on Earth? Is it enough to have an effect on the average age of water molecules?
2
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1answer
179 views

Earth's magnetic field, could the poles be reversing?

Lately, I've been 'monitoring', if you will, the earths magnetic field, i've come across some strange looking activity periodically. I exchanged some emails with a guy from NASA today, Joseph Gurman, ...
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3answers
7k views

Lowest gravity on Earth's surface?

I am trying to determine which on Earth's surface has the lowest gravity. Googling is not finding anything concrete. My natural inclination would be to think of Mount Chimborazo in Ecuador, being on ...
3
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2answers
165 views

How does gravity behave outside the geoid?

I was watching a program about the geoid recently and the relative "height" of the Himalayan plateau gave me an idea. It makes sense for the geoid to be "highest" (is that the correct term?) there as ...
4
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1answer
149 views

Why does air contain $Ar$ specifically?

Air consists roughly of $N_2$, $O_2$ and $Ar$. Why is $Ar$ the relatively common noble gas compound and not for example the lighter ones $He$ or $Ne$?
7
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4answers
615 views

How does water carve rock?

How does water carve rock? And more generally, how does a soft material carve a hard material? Obviously it happens, but is it a continual process (every drop of soft water carries away a minute ...
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2answers
441 views

How to predict sea waves length/height?

I would like to know which are the best methods used to predict sea waves characteristics (particularly predict length/height given water depth and wind speed) and how are they used. My major is ...
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1answer
265 views

Average speed of seismic waves towards the center of Earth

I'm looking at an approximation of the average speed of seismic wave towards the center of Earth. The horizontal path of the waves that affects us directly is well documented, but there is not much ...
9
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1answer
3k views

What is the source of Earth's magnetic field?

I saw on Discovery channel that the source of Earth's magnetic field is the molten iron and metals in the earth's core. The spinning of these liquid metals produces the same effect as electric current ...