# 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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### Input of the relation, source and receptor files into SLB Omega

Is anyone using SLB Omega that knows how to input the source, relation and receptor files that are not using SPS format?
158 views

### 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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### How to extend the Wyllie time average equation to multiple constituents

I understand the Wyllie time average equation How to extend it to multiple constituents ?
1 vote
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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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1 vote
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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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1 vote
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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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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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1 vote
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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} - \...
1 vote
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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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1 vote
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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 ...
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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 ...
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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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1 vote
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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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### What makes special a volcanic pipe to be stable until the mantle?

Comming from this question: Can we really travel through earth's core? I wonder what makes special a volcanic pipe to be stable since the mantle through the surface, in comparison to our try or ...
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### Distribution of terrestrial impact craters

Recently I was looking at a map of known impact structures and I noticed that they are concentrated between the tropical and arctic latitudes, but there is very little near the equator. I can think ...
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### Why were the Interglacial periods in the early Pleistocene spaced about one million years apart, but recent ones only 100,000 years apart?

The Teglen (or Tiglian) interglacial period began after approximately half a million years into the Pleistocene, and the next interglacial (Waalian) occurred about a million years after that. But the ...
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1 vote
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### Least equatorial ( and tidal) bulge consistent with modest amounts of water in polar regions

In World Building I asked a question about the climate of an hypothetical planet. There Vogon poet said that Everyone above 10° latitude will be in permanent drought Considering that there were no ...
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### Is there any free indexed journal that Geoscience students can publish?

I am planning to publish a paper related in Geoscience/Geophysics/Seismology within scope of Machine Learning/AI in particular. Is there any Journal that provide free article publishing for ...
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### Under which conditions would you see the MOST lake effect precipitation?

It's well known that the Great Lakes produce large amounts of precipitation in the Fall. When cold polar air moves over the lakes it causes large amounts of relatively warm moist air to rise, ...
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### Is it possible for tsunamis to occur on deep water planets?

Assume a water planet with an ocean depth of about 200-500 km. Would a very strong ground-quake happening at the very bottom of the planet's ocean floor be able to cause a large tsunami to rise up to ...
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### Why is some ocean on continental crust?

While most ocean crust is formed from oceanic plate formations there are areas of the ocean (much of the Gulf of Mexico, Eastern US coast, North Sea, Arabian coast of India) which appear to be ...
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### Can a planet have both magma volcanoes and cryovolcanos?

I know that the Jovian ice moons have been speculated to have cryovolcanos. I was thinking of the ice planet of Hoth from Star Wars and in one of the video games; it has regular volcanic activity. ...
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### Why are the supposed-to-be results of collision and/or subduction formed in an area where collision and/or subduction didn't happen?

Please correct me if I have said something wrong, as it might be the answer to my question. Also, these are all the things that I've learned through self-studying, so I might have been mislead. ...
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### Seismic velocity relations

I do understand why the seismic velocity decreases with temperature and increases with pressure, but I am not really familiar with the relationship between the velocity with Poisson's ratio. I ...
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