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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I'm a theoretical physics with no insights in Earth Science. Is this exercise dealing with Love Waves?
I was studying Landau's elasticity book and I'd like to enhance my physical views on this problem:
"A plane-parallel slab with thickness h (medium 1) lies on an elastic half-space (medium 2).
...
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Why is it that the Chad and Caspian Sea endorheic basins have not silted over?
It doesn't seem like the Persian Gulf where there's subduction in the Orogeny and the Pebas silted in just a few million years while the Chad and Caspian still exist and in the middle of continental ...
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low-pass filters and gravimetric anomalies
I'm a master's student in geology, I wanted to ask a little more about gravimetric anomalies and low-pass filters. The question is this: If I want to isolate a local gravimetric anomaly from the ...
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Finding a phase velocity and group velocity from stacked seismograph
I have seen the following images with title as "Phase vs group velocity" but never understood how this term applies in following image. how to find the phase and group velocity using R2 in ...
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How does the Rossby number of an air parcel change as it travels northwards or southwards?
I am a graduate student and, in the research project I am a part of, I am tasked to investigate the track of volcanic $SO_2$ emissions. I was comparing the satellite data with the tracks calculated by ...
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Could the electrical potential difference between the Windward and Leeward sides of a mountain range generate electrical current?
I would like to know if it is possible that the electrical potential difference between the Windward side and the Leeward side of a mountain range, due to a thunderstorm occurring on the Windward side,...
user23275
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Simple explanation of what "preferential lattice expansion due to excessive magnesium adsorption", means
In the context of crystal growth, particularly saddle or baroque dolomite development, what does "preferential lattice expansion due to excessive magnesium adsorption" mean in practical ...
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How to compute spherical harmonics coefficients using orthogonality?
I use the lunar gravity model GRGM900C to calculate the gravitational potential across a $360{^\circ}*360{^\circ}$ grid. This calculation follows the equation:
$$V(\varphi,\lambda)=\sum_{\mathrm{n=0}}^...
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hi, any ideas how to convert Rcd and Dst seismic data into SEGY?
any ideas how to convert Rcd and Dst seismic data into SEGY?
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Why does weaker local gravity cause lower sea level?
The weaker local gravity in the Indian Ocean geoid low (IOGL) causes the sea level to be 106 m below the global mean sea level. Why is that ?
"Because of this lower density, the gravitational ...
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Question regarding the breakup of India from Eastern Gondwana [closed]
I wanted to ask this question as it relates to a project I am working on. In this "timeline" when India broke away from Gondwana the Indian Plate took a small piece of land from Eastern ...
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What happens to seismic waves reflected back to the surface?
What would be the behavior of seismic waves when it hit the geological media?
The waves coming from a source hits different boundaries with different energies, the wave will be reduced in energy by ...
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SEG-2 vs SEG-Y file formats
I have limited experience with the different SEG file formats and I was hoping if someone could shed some light on the current preffered file formats used in software applications and for sharing ...
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Inversion of magnetic data
I am working with inversion of magnetic data and one colleague of my supervisor has said this about subtracting the IGRF for inversions:
"””
He needs to subtract a value from them to make the ...
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With the Earth revolving around the Sun , is there some [invisible] "tail" like Shooting Stars & Comets have?
Shooting Stars & Comets have tails.
Here is Example Wiki Image showing Comet with 2 tails :
With the Earth revolving around the Sun , is there some [invisible] "tail" like Comets have ?
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What criteria determines whether earthquakes are classified as new or aftershocks?
I saw a recent paper where it is claimed that aftershocks can occur years, decades or centuries after the main earthquake.
When seismic activity is observed, what criteria determines the ...
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Composition of Earth's Core
Is there a list giving an estimate of the abundance of every element of the periodic table in the Earth's Core - possibly differentiating by inner core and outer core?
I am specifically interested in ...
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What is the reason behind the density being negative value
This is the example density depth functions for various sedimentary sections world wide. But someof the sections marked with red, due to their last term, as i increase the value of z(depth) they ...
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How to compare sensitivity with lithology between different crossplots?
In the given figure, which is plot of various elastic parameter for sand (blue) and shale(red) sequence. How to find Which crossplot has has greater sensitivity to lithology? Also what is mean by ...
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Why is static modulus greater then dynamic modulus in limestone?
Generally dynamic modulus is greater then static modulus and experimental data matches that. But in chalcedonic limestone, the static modulus looks to be greater than the dynamic modulus. What could ...
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What is the reason that some elastic constants are negative?
In this table of elastic constants, indices m = 1 and n = 4 result in negative values. What could the reason be?
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what is the value of y in additive time series decomposition
I understand the additive time series formula is y = trend + Seasonal + cyclic + residual. But what is the value of y. Is it the the combination of trend, seasonal , cyclic and residual which is shown ...
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How to connect drillhole from section to the planar view to calculate dip and azimuth?
We have a set of old sections with drill data that I would like to extract and model. I can add sections just fine in Leapfrog, but I have issues with the drill holes, especially connecting the drill ...
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From how deep in the mantle has any rock ever been brought to the surface? Have scientists found anything they believe originated in the outer core?
I wonder if this is even possible to know....
Do geophysicists and geologists have even a 'theoretical' idea about how deep Earth's churning of its layers goes?
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Identifying continuously-recording seismic stations
I am trying to identify which stations within the NCEDC network are continuously recording ground motion, and which record only intermittently. I am using obspy's ...
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How is the apparent volume affected by particle packing?
This is from paper "The packing of particles" by A.E.R Westman and H.R. Hugill.
Here they give result as, "it is evident that if the diameter ratio is
unity, ie., the coarse and fine ...
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Is the global temperature of the earth a physical quantity at all?
In discussions with physically educated among the deniers of the greenhouse effect, it is repeatedly claimed that it is completely pointless to state a quantity such as a global average temperature of ...
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Necessary Altitude to See Curvature of the Horizon [duplicate]
Many people have asked how high above the earth one must be to see the horizon curve, but I have yet to see a mathematical answer that correlates to the dimensions of the earth. As you rise above the ...
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Do gravity and magnetic field change along a geographic latitude or not?
Along the same geographic latitude does magnetic field change or not, and the same for the gravitational field, does it change along a geographic latitude? Please explain.
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What is a general formula for Earth gravity as a function of radius, given a spherical shell model?
I'm trying to derive the formula for gravitational acceleration as a function of Earth radius $g(r)$, given a spherical shell model where each shell has a constant density $\rho(r)$. If I set $r=0$ to ...
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Where can I get Carbon Capture Storage data?
I need CCS data for Carbon Injection monitoring for a seismic hazard study. Is there any open source data that related Carbon Injection monitoring for example seismic, wells, 1/2/3/4D seismic and etc.
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Did the 1990 Manjil-Rudbar earthquake postpone a massive earthquake in Tehran?
In this site (published on 6 November 2001) I found the following information:
Historical data suggest there is a major earthquake in Tehran every 158 years and the last one there was in 1830.
The ...
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How to calculate latitude and longitude based on relative distance
The coordinates of A on Mars are 125°E and 25°N. The distance of point B is x meters due east from A and y meters due north from A. How to calculate the latitude and longitude of B. Please try to use ...
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Can a tectonic plate subduct under one plate while another plate subducts under it along the same boundary?
At a triple junction plate boundary there are three tectonic plates meeting. We have plenty of examples of these boundaries on Earth, notably the Afar Triple Junction, Mendocino Triple Junction, and ...
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What is technically wrong with Wijngaarden & Happer's paper claiming to show that CO2's contribution to surface warming is saturated?
The paper, Dependence of Earth’s Thermal Radiation on Five Most
Abundant Greenhouse Gases1, has been reportedly rejected from several major journals. By analysing absorption spectra of greenhouse ...
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Impact Erosion Selectivity In Offloading Radioactive Material
ref : https://science.ubc.ca/news/asteroid-impact-erosion-helped-make-earth-habitable
According to the theory of impact erosion, the early crust was presumably much hotter w/ radioactive isotopes (U &...
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I got this error (segyread: format not SEGY standard (1, 2, 3, 5, or 8)) while converting from segy to su format on seismic unix
[ ~/Desktop/demo ] $ segyread tape=data.sgy| segyclean>data.su
segyread: format not SEGY standard (1, 2, 3, 5, or 8)
segyclean: fgettr.c: bad first header
[ ~/Desktop/demo ] $ 3200+0 records in
6+1 ...
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I am trying to write a simple python script for dispersion analysis of surface waves, but I think I am missing something conceptually
I have some simple seismic traces as shown here.
When attempting to perform a dispersion analysis using the technique described by this paper, I get the following image.
Unfortunately, I cannot for ...
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Geotechnology: Prove a formula, calculated with unit weights, for void ratio
I don't know where else to post this.
I am reading a Geotechnical engineering textbook by B.M. Das, 6th edition.
Problem 3.1 is as follows:
For a given soil, show that
$$e=\frac{\gamma_{sat} - \...
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What is the relationship between earthquake risk, magnitude, and distance from the epicenter?
I need a (rough) functional relationship between these three quantities. My initial hypothesis is that the risk $R$ (intended as the probability of a building damage), scales with the square root of ...
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Does this support Hapgood's Earth Crust Displacement Theory?
I'm no Geologist by any standard but I'm quite intrigued by what goes on below our feet.
I came across this article that states there's a new or (confirmed) partially melted layer in the athenosphere (...
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Simple Mathematical Equation for the Geotherm
Hi I need a simple equation (polynomial third straight) for a PerpleX simulation to represent the mantle geotherm. The geotherms I have found on the internet so far (unfortunately I don't have the ...
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Where could I get waveform data on low-frequency earthquakes, very low-frequency earthquakes, volcanic tremor and non-volcanic earthquakes?
I am a marine geology masters student and I am writing my thesis on slow earthquakes. I will include graphs of the most common types of earthquakes:
Low-frequency earthquakes
Very low-frequency ...
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Is it possible that the rainbow sand dunes in Death Valley, California were formed by some massive mining in the ancient past? [closed]
I know there is a mainstream answer that thinks the rainbow sand dunes they be explained geologically... I just want to know if it's possible to form those colors and those dunes from mining? And if ...
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Why does calcium occur together with felsic rocks and magnesium with mafic rocks if calcium is denser than magnesium?
Felsic rocks contain a lot of sodium, potassium and calcium (and a great deal of aluminum), while mafic rocks consist of a lot of magnesium with iron....
Why is this?
Why is magnesium (z=12) in the ...
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How does the rotation of Earth's inner core influence climate?
In the recent paper published in Nature that sugests a 60-70 years inner core rotation cycle, it is said:
Interestingly, the same multidecadal periodicity is also well observed
in the Earth’s climate ...
user28185
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How much fresh water could be produced by pumping warm humid air through a pipeline up to the top of a mountain?
I have been doing a lot of research on the Internet lately about various desalination processes which are being used today and this led me to begin studying about mountain weather and the orographic ...
user23275
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Does the high pressure inside the Earth's core contribute to its high temperature?
The explanations for why the Earth's core is hot I found on the internet included:
leftover energy from the Earth's formation
radioactivity of the elements inside the core
friction between the core ...
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Relation between highlands and tidal forces
Could the presence of mountain ranges in continental areas near to tectonic plates boundaries prevent these plates from swaying up and down as a result of vertical tidal forces and plastic ...
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Where can I access public sonic well-log data?
I'm doing some research and I'm in need of some well-log data from a sonic tool. I'm specifically looking for a multi-receiver tool with 6 or more receivers if possible.
I've been able to find a lot ...
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