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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Is it possible for Mexico to have a magnitude 9 earthquake?

Everyone has heard of the Cascadia Subduction Zone and the potential threat it poses. However, I have heard nothing about The Cocos Subduction Zone, even though it caused a devastating earthquake over ...
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Will California become a subduction zone in the distant future

California is one of the few places in the world that lie on a transform fault. My question is why considering the fact that North American Plate is moving westward shouldn't California be a ...
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How do I find the temperature measured at 350 hPa?

You are flying 2.5 km over the ground while your mates are flying up at 350 hPa. All the way between you there are clouds. If you measure that the temperature outside is 4 celsius, what temperature do ...
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How did the Ural mountains form?

A nice picture for "how mountains formed" on Earth is due to the motion of tectonic plates. As the plates crash together, mountains may get "pushed upwards". However, a quick look at a map of the ...
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How do I find the temperature of the air mass, and how do I use a t-skew chart?

So the first problem I'm stuck on is this one: 1.An airmass is moving down a mountain from point A to B.At A the temperature is -10 celsius and the pressure is 890hPa. At point B the pressure is 1010 ...
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How does rotating water affect turbulence?

I have been doing some DIYnamics with rotating water and non-rotating water. So I had a bucket filled with water on a rotating table, and waited for it to be in solid body rotation. I then dropped ...
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Is there a way to convert from Dip direction to Strike direction?

I have some set of recorded data in dip direction/dip format. I wish to transform then to strike/dip. I am currently having a hard time imagining how to convert from dip direction to strike direction. ...
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What exactly are enantiotropic and monotropic polymorphic transitions?

Recently, I've been studying the subject of polymorphism and met two important concepts, the monotropic and enantiotropic polymorphic transition types. However, I can't really seem to grasp the ...
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How do scientists know the precise location, etc. of the earliest supercontinents? Or their configurations far, far into the future?

Obviously, we can look at where continental plates are currently moving, and extrapolate both forwards and backwards in time... But there have (allegedly) been more than supercontinent in the past... ...
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Why does Meteorology rely on a spherical model of the earth, rather than a flat earth, to function? [closed]

I hear all the arguments one explains to a flat earther as to why the earth is Spherical and not flat. I am not a meteorologist, but I know enough Meteorology for me to fly safely as a pilot. Getting ...
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What would be the phase shift and polarity of a seismic wave upon reflection

What would be the phase shift and polarity of a seismic wave a) when it hit the free surface b)when the free surface reflection goes down and hit a reflector and returned to the receiver placed on the ...
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Mechanism for Pluto's young surface

According to recent reports (e.g. in Nature), Pluto is geologically active. It has some mechanism by which it has "recycled" its surface. I originally thought we had a similar case to Jupiter's moon ...
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Relationship Between Ratio of Atmospheric Gases and Ocean Gases

A version of this question was posted in Chemistry SE and Worldbuilding SE but I've been told it wasn't appropriate to either SE. I was told to give this SE a chance. If you think it doesn't belong on ...
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Broadband Albedo Conversion Scheme

I had this albedo conversion written down: $$\alpha = 0.53\alpha_{VIS}+0.47\alpha_{NIR}$$ I had on my notes that this equation was form Collins et al (2002). However, I cannot find where this came ...
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How quickly is the Earth shrinking?

Except for ice, acetic acid, bismuth and gallium and a few other things materials generally shrink when they cool and solidify, so I'm pretty sure Earth has as well. It probably wouldn't be ...
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Why do clouds have ceilings and bases?

What is the point called when water can not rise above or visually seem to have a ceiling in the atmosphere? What makes that point ideal?
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Why doesn't the Earth's outer core dissolve into the mantle?

It is well accepted that the outer core is made out of liquid iron and nickel, and as everything else it should tend to reach chemical equilibrium with its surrounding. In particular, I would expect ...
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How do the different densities of the oceanic and continental crust affect earth's outer shape?

I am currently reading a textbook and I am slightly confused at a paragraph that deals with some general facts about earth's outer shape. It mentions that the density of the continental crust is ...
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Principal component analysis (PCA) and normalization of radiometric data?

I did some experiments with airborne radiometric data in a region in southern Brazil and I would like to know your suggestion about the following topic: I tried to classify high, medium and low ...
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Can an igneous rock have a Vp of less than 1000 m/s and need blasting to excavate?

I have run a 60 m refraction seismic line on a mountain summit. The environment was noisy (wind would be the principal agent) and quite difficult to pick first arrivals. It resulted in 800 m/s. A ...
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Why is ocean surface velocity around 3% of wind velocity?

Many introductory level textbooks suggest that, as a rule of thumb, the velocity of the ocean surface is around 3% the wind velocity at 10 meters above the sea surface. For instance, Ocean ...
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1answer
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Rainbowish phenomenon outside my home

I took a photo of an amazing sight I had never seen outside my home ( southern india ) but I could not tell if it was a rainbow type thing or an aurora borealis. Also if it was to be a sun dog , ...
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stretch phenomena after NMO application on seismic data

after the NMO application we have stretch for far offset , i read a lot of articles but i can't have a complete idea how this phenomena is really created ! any one have a rich explanation ?
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Construction of a drift curve in the well tie calibration and how to interpret it?. Sonic calibration vs checkshot calibration

Good afternoon. Inside the creation of the synthetic seismogram some softwares have the option to run what is called "sonic calibration" or "checkshot calibration". I have some questions: 1)why some ...
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How does the changing seasons affect the large scale easterly flow of the ITCZ?

I am new to climate science and have been learning the basic picture of the intertropical convergence zone (ITCZ) and how this leads to the predominant easterly "trade winds". The picture that I ...
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How do Rossby Waves in the ocean form?

So on land, I believe that one factor in their formation is due to inhomogeneities in surface heating between land and ocean (and also inhomogeneities in surface heating due to terrain effects like ...
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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 ...
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Why is the inside of the Earth so hot?

I have heard that the Earth is made up of four layers, being the crust, the mantle, the outer core and the inner core. I have also heard that the Earth's temperature increases as you move from the ...
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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!
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Could the Earth's core lose its heat?

Will all the drilling and digging to use the Earth's natural heat as geothermal energy affect the Earth's core, causing it to cool down? If so, would it result in an ice age? If not, how does the ...
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How does geothermal heating work?

I have heard that geothermal heating is a way of generating energy from the temperature difference between the inner layers of the Earth and the Earth's crust. How is it possible to extract this ...
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Geo-Spherical shape of Earth

I know that the best possible approximation of the shape of earth is an oblate sphere. But people also call it as geo-spherical shape of the Earth. What is the meaning of geospherical shape? Does this ...
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Is earthquake prediction possible?

After the Tohoku and East Coast quakes, I skimmed over several books discussing the validity of earthquake prediction as a discipline, yet found no significant breakthroughs. What should change in our ...
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How do you choose appropriate parameters for a lowpass filter when filtering a Bouguer anomaly?

I am trying to filter my Bouguer anomaly data to remove the short wavelength features. I have created a lowpass filter to achieve this, but I am wondering how I can more objectively choose my cutoff ...
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where are the poles of rotation of the tectonic plates located?

Euler's "fixed point" theorem ... can be stated as: The most general displacement of a rigid body over the surface of a sphere can be regarded as a rotation about a suitable axis which passes ...
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Why do we consider hydrostatic pressure and lithostatic pressure separately?

In petroleum geology, why do we consider hydrostatic pressure and lithostatic pressure separately? Surely the pressure at any point, whether fluid or rock, at depth is simply equal the weight of all ...
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How can I calculate the sensitivity of a seismometer?

I would like to know if a specific seismometer can measure 1 micron/sec velocity. I have a few specs from the datasheet but I'm not a seismologist and am trying to figure out how to relate the specs ...
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How all of the files listed as stream (st) could be used or listed as traces (tr) in obspy (python)?

PPSD (seismic background noise) I list all of my files, basically as components (H1, H2, and V), as streas as follows: import os from obspy import read from obspy.signal import PPSD import ...
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What is the simplest meteorological model to operate?

For teaching purposes I am looking for an atmospheric model that can be easily installed and the input data can be easily read and prepared. Preferably I would like to run a global low resolution ...
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Why is Earth's outer-core liquid?

The Earth's inner core is solid because despite the enormous temperature in this region, there is also enormous pressure there, which in turn raises the melting point of iron and nickel to a value ...
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Q factor estimation from VSP

in seismic data processing there is a step of calculating the absorption represented By Q value which is Q factor , how we can estimate it from VSP ! thank you.
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Are old geophysics textbooks useful?

I have had much success with old textbooks in mathematics. Generally, for any branch of mathematics that I (as a non-mathematician) would like to learn or re-learn, I can buy a classic textbook from ...
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How to convert mol/m^2 to total mass ( e.g gram, kg etc )?

I want to calculate the total $\rm{NO_2}$ amount in a year using satellite Sentinel-5p NO2 dataset. But the problem is sentinel satellite data stored in $\rm\frac{mol}{m^2}$ unit. But I have to ...
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Performing time-frequency analysis (FTAN)

I am trying to do ambient noise tomography and I am quite confused on how to perform time-frequency analysis (FTAN) as shown in figure 13b and 13d of this paper by Bensen et al.. I am using Python and ...
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How many days has it been since the Cambrian explosion?

I want to know how to calculate the number of days since an event in Earth's past, and am using the Cambrian explosion as an example. I define a day to be one rotation of Earth with respect to the ...
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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 ...
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Waves in very thin layer

Elastic waves in the earth are described by the elastodynamic equations \begin{align} \rho \frac{\partial^2 u}{\partial t^2} &= (2 \mu + \lambda) \frac{\partial^2 u}{\partial x^2} + \mu \left( ...
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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, ...
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How long for tectonic plates to develop from a planetary, molten planetary surface?

On Earth or an Earth-like planet, how long does it take for a molten surface to solidify into planetary crust, and how long does it take for that crust to develop into tectonic plates?
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Energy Density of Porous Rocks

It's very long, I know. But please, don't be discouraged from going through this question if you can help me. The question is at the second to the last paragraph, but you need to read through to ...

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