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Questions tagged [geophysics]

Geophysics is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment.

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2answers
86 views

Can the sealed bottle garden be called a perpetual motion machine? [closed]

I was not sure just where to ask this question, but I was wondering if the sealed bottle garden be really called a perpetual motion machine. http://www.dailymail.co.uk/sciencetech/article-2267504/The-...
5
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1answer
7k views

What is difference between divergent boundary and hot spot?

As I know, both divergent boundary and hot spot are formed by rise of magma of convention, but divergent boundary is a line and hot spot is a point, is there difference between 2 kinds of rising magma?...
3
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2answers
157 views

Conditions at the bottom of a VERY deep hole

I'm a science fiction author looking to describe what conditions might be like at the bottom of a cylindrical shaft ~ 30 meters across and ~ 35 km deep. It's located somewhere on the edge of ...
2
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0answers
39 views

Phase of S2 constituent in tidal prediction

I ran the ETERNA code for the prediction of tidal gravity at some station. Then I use Fourier analysis to recover the amplitude and phase of the S2 constituent. As I understand, the phase of the S2 ...
5
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1answer
387 views

Global scale seismology experiments / observations disproving flat earth conspiracy?

Recently I've taken an exceptionally unwise interest in the beliefs on conspiracy theorists, in particular flat earthers. Flat earthism has been trending heavily lately and indeed is undergoing some ...
3
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1answer
108 views

Do our continents lay on the mantle because solid silicon dioxide is less dense than its liquid form?

I don't know whether quartz behaves like ice or not, but could it be because silicon dioxide, which the continents are made of for a big part, is less dense - so the continents lay on top like ice on ...
6
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1answer
163 views

Why is ground water rising on these forest rings?

I am seeking a physical explanation for this; There is huge amount of such a Forest rings in Earth; (Link to Google Maps to one ~400 m Ring) They range in diameter from 30 metres to 2 kilometres, ...
5
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3answers
7k views

Does a mountain top have higher gravity than a nearby sea-level surface?

Regardless the latitude and centrifugial 'force' is the gravity on mountains higher or lower than at sealevel? Gravity is depending on the radius to the centre and the mass. Now if you are on a ...
12
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5answers
2k views

Are there water molecules in the oceans which will almost never fall down as rain?

Some oceans are very deep. But is there also current (convection) deep in the ocean so that all water molecules will ones be evaporated and fall down as rain or is it very quite at the bottom so some ...
1
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1answer
394 views

Will the Earth's core cool? [duplicate]

I am doing a school project and need to know... Will the Earth's mantle or core ever cool? If so, how? Thank you!
13
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1answer
526 views

How is known that the Earth core is solid?

As I know, the Earth core is solid. This is known, because it conducts also transverse waves, while liquids conduct only longitudinal waves. But, how was it found? The inner core is in the outer core,...
10
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1answer
223 views

Carbonate reef not horizontal in seismic section?

Carbonate reefs usually appear as homogeneous bodies surrounded by sediment layers in seismic reflection data, but in the figure below the high amplitude reflection from the top of sediment (layer 2 ...
5
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1answer
491 views

How does Vertical Electrical Sounding Work?

I recently conducted a brief training exercise with VES equipment, although it had to be called off due to rain. I can't help but wonder about the basic physics of it, why is it that increased ...
4
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1answer
353 views

Why is fluid pressure in a fractured rock reservoir only dependent on hydrostatic pressure?

Why does lithostatic pressure not play a role? (or does it?)
4
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1answer
168 views

Gravitational Anomaly of a subsurface body

How does the gravitational anomaly measured at the Earth's surface and produced by a subsurface body depend on its depth and on the density contrast of the body relative to its surroundings?
8
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2answers
2k views

How viscous is the Earth's mantle?

I'm posting here to get some more expert information based on this question. If the Earth were to stop rotating, removing the centrifugal force causing the equatorial bulge, how long would it take ...
12
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1answer
689 views

What's the distance between the center of mass and geometrical center of Earth (CM-CF offset)?

I asked the same question on Physics StackExchange site. I now know that there are several types of "center" and I can tell, I'm interested in the CM-CF offset (CM = geocenter, CF = center of figure). ...
3
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1answer
539 views

Seismic data processing software

For processing seismic data, why is Seismic Unix so important? What distinguishes it from other seismic processing software like GLOBE Claritas or Omega? Is it argued that processing capabilities are ...
2
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0answers
88 views

SeismicUnix - Finite Difference Migration [closed]

I'm trying to apply sumigfd on simple.su data which is used in the John Stockwell course in geophysical image processing - in the Migration chapter on page 85. I have not had any success because the ...
6
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2answers
496 views

How bad is geo-engineering?

It is just curiosity that forced me to ask this question. At some point in time, if we can't control global $\sf{CO_2}$ emissions, temperature will increase until a tipping point and it will be a ...
8
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1answer
133 views

Regarding velocity of P/S-waves

I feel like I am missing something blindingly simple, but I am curious about something. We are given the velocity of a P-wave as $v_{p} = \sqrt{(K+\frac{4}{3}μ)/ρ}$. So I am to understand ...
10
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1answer
3k views

Why is the South Pole colder than the North Pole?

This question popped into my head because I am designing a fictional world map, and I was wondering what factors influence the amount of ice at poles. I want to know why there is much more ice ...
6
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1answer
2k views

Compute direction of gravity vector

As I understand to compute vector of gravity not saficient to compute normal to elipsoid, but we need to computer normal to geoid (by definition geoid is a surface to which the force of gravity is ...
11
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4answers
5k views

Does gravity differ from place to place on Earth

Does a particular object have the same weight on every part of Earth or does it vary?
3
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3answers
239 views

How probable is is that earth magnetic field will change 180 degrees at once?

Today the Earth's magnetic field is moving a little bit. But is there going to be a point where the field suddenly radically changes direction? If so what is the cause of that? If not, then is the ...
2
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1answer
2k views

Why are oceans so deep?

Some areas of oceans are about 11 km deep. Is it because continental plates were moving away because of troughs in the middle from where new rock is formed? If so, why did it become deep? If not, what ...
4
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1answer
130 views

Is there a differential angular rotation on Earth?

I asked a question about solar day difference between two latitudes on the same longitude here on the Earth surface. The answer was clear due to constant angular rotation time is the same. Tangential ...
5
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1answer
705 views

Is there a time difference between two points at the same longitude but at different latitudes?

Assume we have two cities A and B both at the same longitude (say $45^{0}$ E) but at different latitudes say $8^{0}$N and $90^{0}$ N. Can we get a time difference between these two cities. I raised ...
9
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2answers
593 views

Terrain correction for gravity data using Nagy, 1973

I am working with an algorithm for terrain correction of gravity data. I am using Nagy, 1973. However, I could not get the results I need. So, this is the problem. I have this function where x,y,z ...
9
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1answer
181 views

What is the current status of geophysical global cooling theory?

Plate tectonics effectively rubbished the theory of geophysical global cooling as a means of explaining many surface features on the Earth. However, this wiki says that the same process is responsible ...
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2answers
284 views

Next Ice age may be unavoidable

During the warm period before the most recent ice age, 120,000 years ago, roughly half of the Greenland ice sheet melted.This is thought to have been the cause of the last ice age. Question: If this ...
7
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3answers
349 views

Why is the elevation of the Iberian Peninsula so high?

The Iberian peninsula lies more than 600 m above sea level, on average, far above similar geological regions in western Europe. Even tectonically undeformed areas in the inner basins present a ...
4
votes
1answer
67 views

Where to start with P190s Seismic Navigation Files?

I have a few P190s navigation files from a 2D reflection seismic acquisition shoot and wondering what the best way was to extract UTM's (or latitude and longitude) and depth. I am reading through the ...
40
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10answers
24k 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 ...
4
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0answers
49 views

meaning of Grid resolution [duplicate]

I have some queries regarding grid. What does this mean. The grid has spatial resolution of 1/2 degrees latitude × 2/3 degrees longitude.?
0
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1answer
127 views

If we could stay still in the air. Would we be travel around the entire world in 24 hours? [closed]

I just wonder why, if we ourselves could stay still in the air (or just float in the air using something such as a hot air balloon). Why doesn't the world rotate around us, allowing us to travel ...
5
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1answer
100 views

Wobbly Tire Theory — Is there an existing theory that fits the following description?

I am not an earth scientist but for many years I have wondered about the following. I am curious if this has already been explored by scientists? If so, what is the theory formally called? and what is ...
16
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6answers
6k views

How to quickly or easily prove the world is spherical?

A relative of mine has recently introduced me to the modern flat earth theory, which she believes in. Setting aside for the moment that it is ridiculous, and that sending up some balloons with cameras ...
6
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1answer
217 views

Cross-line fold of a towed-streamer survey

On page 29 of the book 3D Seismic Survey Design by Gijs O. Vermeer, Vermeer says that the equation for a maximum fold in a 3D survey is the following: $M = M_i \times M_c$ where $M_i$ is the inline ...
3
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1answer
137 views

Which component in a 3-component Sp receiver function is the actual Sp RF?

In a 3-component Sp RF I have the green's function in P,SV, and SH. The actual component to the RF that shows the Sp conversion (the one always published in the literature), which would represent as a ...
6
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1answer
148 views

How did the intensity of Earth's magnetic field change through geological time?

Looking at the wikipedia article on the Earth's magnetic field, I see that its strength varies through time. How did Earth's magnetic field change throughout its history, from the beginning of the ...
6
votes
1answer
180 views

How high do you need to be to see Los Angeles from Washington DC?

If you were to stand on a tall building in Washington, DC and looked west, how tall would the building need to be to see Los Angeles? I would like answers based on if the world was flat and if the ...
3
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2answers
98 views

Is there a risk with putting out smouldering underground coal reserves? [closed]

According to this Discovery News video about Centralia Pennsylvania and other underground coal fires, there are many smouldering underground coal reserves making the land above it uninhabitable to ...
5
votes
1answer
183 views

Glossary of oil and gas industry geophysical terms

Reviewing market regulatory standards I came across the problem of finding a source that I could cite of concise, worldwide accepted industry geophysical terms. So far I know Schlumberger Oilfield ...
4
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1answer
470 views

Using the Born approximation in seismic inversion

In physics, the Born approximation allows us to separate the wave-function in terms of electronic and nuclear components. Why is this concept relevant in seismic inversion? For example in Colombi et ...
5
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1answer
706 views

Calculating magnetic declination for a non-axial dipole field

I'm trying to answer the following question: Compute the inclination and declination of the magnetic field that would be observed in Boulder, Colorado (40°N, 105°W) if the Earth’s field ...
3
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2answers
2k views

Effect on poles when Earth is not tilted [closed]

Say a Mars size object hits the Earth in such a way that it knocks the Earth in a straight 0 degree angle, and let's assume that we somehow do not go extinct. What would happen to the poles in this ...
3
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1answer
104 views

Quantitative mapping of air pollution Sifakis and Paronis

I am reading this paper about deriving AOT and I have found this ...
6
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1answer
179 views

Can the crust be compared to an arch?

Since tectonic plates are held together by lateral stress, friction, and gravity, and the Earth is a sphere, they work just like a full-circle arch or full-sphere dome. So can the crust be compared to ...
-6
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1answer
463 views

Is it possible that the recent droughts are signs of epic crust failure? [closed]

The full question is: Is it possible that the recent, successive, long droughts from Australia to the West Coast of both American continents are signs of epic crust failure? The question is aimed ...