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Questions tagged [geophysics]

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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Electric potential due to a current source - Basic equations

In my book I found the folowing formula of the electric potential generated by a current source: $$ \Phi = \frac{I}{4 \pi \sigma} \frac{1}{r} $$ where I is the current, $\sigma$ the electrical ...
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Why do P-waves cross each other for small angles?

The following is an image produced by ObsPy of P-waves entering the earth just below the surface at small angles depicting the problem: I wish to understand why the P-wave rays cross each other at ...
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1answer
71 views

Asteroid Theory of Dinosaur Extinction [closed]

Have proponents of the Chicxulub dinosaur extinction theory wildly exaggerated the effect of asteroid impact in order to validate their theory? For example,the world-wide forest fire claim doesn't ...
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3answers
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How does the Earth's center produce heat?

In my understanding, the center of the Earth is hot because of the weight of the its own matter being crushed in on itself because of gravity. We can use water to collect this heat from the Earth and ...
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What would earth's wind look like without differential heating?

If the earth were not subject to differential (solar) heating, but otherwise had the same atmospheric and surface temperatures, and same rate of rotation: What would its wind look like? E.g.: Would ...
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1answer
82 views

How do big rocks split in half? [closed]

So, recently I was on a trip in which I could observe a lot of huge rocks (1 to 20 meters in diameter), and I found odd how in several occasions rocks would be split in two parts, with a neat division....
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31 views

How much must the Sun's radiation be reduced to offset global warming?

About 70 % of earth is covered with clouds and the rate of atmospheric water vapor is increasing. Also the warming of the oceans will most probably cause more and deeper low pressures and increased ...
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31 views

Rainbow angle equals tropics inclination… a coincidence?

An observer from ISS can find a rainbow forming under certain conditions ( of internal reflection /refraction) in a cloud of water droplets at the equator. It may be regarded as equivalent to a ...
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33 views

Stability of a 10km planetoid with a micro-black hole in its centre

Let's assume there is a tiny, 10km-radius planetoid with a micro-black hole in its centre of about 10^19kg, so the surface of the planetoid is at 1g. How it appeared (or was constructed) would be the ...
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40 views

How does Bullheading work?

Bullheading, a method of Well Kill, involves simply pumping the kill fluid (heavy fluid) directly down the well bore forcing the well bore fluids back into the reservoir, does the heavier fluid flip ...
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37 views

Can we image the interior of the earth by shooting weakly interacting particles through it?

Could we image the various layers of the earth by shooting weakly interacting particles through it? Let's say we shot a very high amount of neutrinos in one side (say, the north pole) and then ...
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1answer
137 views

What exactly is delta-14C and why are there periodic plateaus in the delta-14C curve?

I downloaded the IntCal13, IntCal09, and IntCal04 datasets (parent site), and when I plotted the last 24k years was surprised to see a plateau or even reversal appear every ~5300 years. Apparently we ...
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Temperature as function of $CO_2$

The carbon stored in fossil fuels must have been taken out of the earth atmosphere from CO2 in past periods by plants. Thereby reducing the amount of CO2 drastically and increasing the amount of O2 to ...
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28 views

How to change rotating frames?

This problem is related to rotating reference frames. $p$ is a precessing frame or turning table that rotates at $\mathbf{\omega_p}$, and $m$ is a container that spins on the top of the turning table ...
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0answers
50 views

Estimating the Pressure of Earth's Center

The pressure of a medium of density $\rho$ and in a graviational field with strength $g$ at a depth of $z+dz$ is equal to the pressure at $z$ plus the pressure caused by the weight of a slab of volume ...
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1answer
48 views

How long for released dye to uniformly saturate the oceans?

Suppose a supertanker filled with purple dye breaks open at a particular point in the middle of the Pacific Ocean and spills an enormous volume of purple dye into the ocean all at once. Imagine that ...
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5answers
135 views

How can an electrically neutral planetary core be geodynamo? [duplicate]

The standard theory for the earth's magnetic field is that the planet's core is a geodynamo. I know moving electric charges can induce a magnetic field, but I also know that opposite charges produce ...
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4answers
54 views

Do CFCs get emitted in air from appliances?

Do the refrigerators and air conditioners that use CFC or HCFC cause damage to the environment even when they are working normally. I mean, is there any gas emission under normal conditions when the ...
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1answer
486 views

How do we know the Earth's core is Molten with Seismology?

My current knowledge about how the core of the earth was discovered is the observation made from non returning/reflecting sonar signal when sent to deeper depths through the earth's crust/mantle. How ...
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1answer
60 views

How did Mars lose all its surface water?

A lot of geological evidence suggests that Mars once had quite a bit of surface water. I assume it wasn't whisked away into space, so where did it all go? What processes caused the water to go there? ...
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61 views

Do a floor tile or dry sand conduct electricity

If you touch an electric wire while standing on a ground made of soil or floor tile, you will get electrocuted. So, electricity passes through it. Right? Shall I conduct an experiment by passing ...
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1answer
50 views

Has there been a quantifed estimate of the thermal impact of human activity? Not to include “greenhouse gasses” [closed]

In 1984 I read a prediction by the biological scientist and Nobel Laureate Konrad Lorenz that heat produced by human activity would necessarily increase Earth's average atmospheric temperature. His ...
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3answers
42 views

High pressures under ocean surface

I read a book about deep water exploring in mariana's trench. They of course talked a lot about pressure, and so this question came to my mind: If you're, say, 2km down in the Mariana's Trench there ...
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2answers
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How can I calculate the ratio of distance between 2 longitudes at different latitudes?

Suppose i have to calculate the ratio of lengths of AB and CD where A(0° N,0° E) and B(0°N,30° E), and C(30°N,0°E) and D(30°N,30° E) the values are just as an example.Is it possible to get the ratio ...
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1answer
36 views

young's modulus vs longitudal deformation modulus

Young's modulus is typiccaly denoted with E. I have come accross a similar quantity called longitudal deformation modulus (in Russian literature, they call it модуль продольных деформаций) and it is ...
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3answers
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Max. air temperature on Earth [duplicate]

Is there any max. temperature that air on Earth could reach, assuming that solar radiation is standard and the average temperature on Earth is 14.6 like today? I mean, is there any chance that the ...
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1answer
67 views

A sound argument for existence of Americas, along al-Biruni's lines?

In 11-th century, Al-Biruni computed circumference of Earth with high accuracy, and mapped all then-known terrain. He then argued that the unknown part of the globe cannot be all ocean, predicting ...
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2answers
84 views

Global warming and air temperature

The layman's question. Is there a maximum temperature that can be reached by air on Earth due to global warming? For example, one that would prevent living organisms from functioning? I read somewhere ...
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0answers
121 views

Seismology - PPV / VDV from geophone waveform data

I'm using an inexpensive seismometer to try and measure the effects of local HGV traffic on buildings. The device is connected to a Raspberry PI that has a Cirrus Logic Audio Card. The signal is fed ...
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2answers
188 views

Shape of Earth's magnetic field

Why earth's magnetic field is compressed on day side and extended like tail on night side, like this I know that it's due to solar wind but not how that compression and extension happens.
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4answers
96 views

Is effective gravity constant over the surface of the ocean?

According to Wikipedia: The Earth is not spherically symmetric, but is slightly flatter at the poles while bulging at the Equator: an oblate spheroid. There are consequently slight deviations in ...
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0answers
64 views

Black hole internal mathematics

I read the article about mathematicians-disprove-conjecture-made-to-save-black-holes and was wondering: could we compare the universe to Meteorology and geophysics on earth to answer some of questions ...
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1answer
88 views

Are North aurora and South aurora produced by positive and negative particles respectively?

Are North aurora and South aurora produced by positive and negative particles respectively?
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3answers
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What determines the shape of lightning? [duplicate]

Everyone's seen lightning streaks, either in real life or in pictures and videos. My question is, why does it look the way it does? Does lightning spread in a random manner, or is there physics ...
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1answer
243 views

What happens if Earth loses its magnetic field?

Earth's magnetic field is shifting at a high speed does this mean earth will lose its magnetic field and if it does are we in danger or if it doesn't what are consequences of the poles shifting
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Computing the porosity of a core sample from a set of digital images

Are there any references of books and/or papers about methods to compute the porosity of a given core sample (from an oil and gas reservoir) if this core is given as a set of digital images (for ...
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2answers
162 views

Why Earth is like a magnetic dipole?

Earth’s magnetic field is mostly caused by electric currents in the liquid outer core, which is composed of conductive, molten iron. Loops of currents in the constantly moving, liquid iron create ...
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1answer
39 views

What is below a tectonic plate?

I know that tectonic plates float on mantle but when two plates move away from each other, is the mantle below them exposed to the surface?
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129 views

Calculate Height of Ocean Tides if Earth Had a Larger/Smaller Radius

For context, I'm coming at this question from the Worldbuilding stackexchange, where I've posted a related question. I'm not a physicist or scientist by training, so if I make any glaring errors, ...
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1answer
447 views

Why Earth’s magnetic field is reversing its direction every few million years? [duplicate]

Just now I was studying the Magnetism and Earth's magnetic field source. when I read that the earth's magnetic poles are not fixed and keep changing ( the north becomes south and the inverse) every ...
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1answer
60 views

Is there a way to express stream power for an entire watershed?

Fluvial geomorphologists describe stream power, $\Omega$, as the 'rate of energy dissipation against the bed and banks of a river per unit downstream length'. It is expressed as a function of water ...
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Growth of iron crystals

What determines how large a crystal of iron will grow when heat and pressure are applied? I was thinking about the Earth's core. Some have postulated that a large iron crystal is at the center of the ...
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50 views

How long would rising hot air from a 15,000 meter (49,000 ft) hole in the earth's surface stay warm for?

The deepest hole drilled in the earth is the Kora Borehole. At 15,000 meters (49,000 ft), the temperature was projected to reach 570 degrees F (299°C), so drilling was abandoned. My question is, if ...
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2answers
131 views

What factors affects the cold temperatures in high altitudes?

Why it is that high altitude areas are colder than low altitude areas? Is it because the air pressure or any other? If we consider it with the sun rays, high altitudes receive sun rays earlier than ...
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2answers
867 views

Venus, Earth and Mars Magnetic fields

Why does Earth have a magnetic field, while it appears that Venus and Mars have none or very little?
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1answer
89 views

Earth's gravitational Field vs. Mars's and Venus [closed]

Why does Earth still have an active, Hot interior core, but Mars and Venus have none?
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1answer
286 views

How have “natural” permanent magnets been magnetised?

Is there a generally accepted theory about how permanent magnets on the earth have been magnetised by natural processes? We have earth's natural magnetic field that could be responsible but in order ...
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1answer
1k views

Why is there more land-mass in The Northern Hemisphere? [closed]

So, this has been bugging my since my youth. When looking at a map of The Earth. In the Southern Hemisphere, both Africa and South America are tall and slim, they get thinner towards the pole. Then ...
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1answer
87 views

Mountain Gravity

Because gravity weakens the farther you are from the mass. Would standing on the side of a mountain change the direction gravity pulls on you because you are closer to the mass of the mountain then ...
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1answer
429 views

Why is Earth's magnetic field so stable?

This answer explains why the Earth has a magnetic field, this answer explains why the Earth's magnetic field flips. However, neither seems to answer the question of why the Earth's magnetic field ...