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13 votes
3 answers
3k views

What are the distinguishing features of an "artificial seismic wave" (e.g. a large underground explosion)

IN the NPR news item North Korea Possibly Conducts Sixth Nuclear Test, South Korea Says: The U.S. Geological Survey says it detected a 6.3 magnitude "possible explosion" near Sungjibaegam, ...
uhoh's user avatar
  • 7,122
10 votes
1 answer
646 views

Stochastic seismic inversion

Could anyone recommend a free and reliable software capable of Stochastic seismic inversion for my project? am aware that Petrel is capable of Genetic inversion based on a non-linear multi-trace ...
Taiwo's user avatar
  • 173
8 votes
1 answer
3k views

How do I extract seismic amplitude on an interpreted horizon?

It seems that seismic amplitude extracted on an interpreted horizon is good for showing channels. E.g.:http://seismicatlas.org/entity?id=98a83c60-ea81-47cc-9304-6041f6ec5277. It seems that often the ...
Andy's user avatar
  • 275
8 votes
2 answers
375 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 ...
geofisica's user avatar
7 votes
1 answer
9k views

SEGD and SEGY recorded data

What is the difference between a segd recorded data and a segy recorded data and can we convert from segd to segy and vice versa?
Kunal Rathod's user avatar
7 votes
1 answer
241 views

Should RTM amplitudes (pre- and post-stack) be related to rock physics properties?

There is as huge uplift in the image quality near and under salt bodies (e.g. the Middle Miocene of the deepwater Gulf of Mexico) by using reverse time migration or RTM. We can now make accurate ...
Blind squirrel's user avatar
7 votes
1 answer
1k views

Available Matlab code to design Seismic Colored Inversion Operator?

I want to apply seismic colored inversion technique to my datasets. Is there a Matlab code available that I can easily use? Are there any other recommended codes to apply seismic colored inversion?
Satya's user avatar
  • 71
7 votes
1 answer
2k views

What is the meaning of seismic spectral blueing?

What is the meaning of seismic spectral blueing? Please cite any good introductory materials if possible.
Kunal Rathod's user avatar
7 votes
1 answer
1k views

Analytical solution for seismic wavefield in MATLAB

I have been trying to evaluate the analytical solution for a wave travelling in a homogeneous, infinite media. For a given source $S(t)$, the wave-field can be calculated at a distance $r$, for a ...
Amartya's user avatar
  • 347
6 votes
1 answer
1k views

What is the relationship between raw seismic data, CMP Stacking, NMO & Machine Learning

I recently joined a geophysics project to assist with some of their machine learning modeling but am trying to gather the domain knowledge required to participate. Something I don't quite understand ...
JGG's user avatar
  • 163
6 votes
2 answers
125 views

How to produce random numbers from seismic data?

I have read that the University of Chile uses seismic data to produce random numbers. (https://random.uchile.cl/randomness-beacon). Does seismic data real have randomness and if it so, which ...
ofenerci's user avatar
  • 163
6 votes
1 answer
459 views

Seismic migration concepts

In Dr Hua-Wei Zhou's book Practical Seismic Data Analysis (2014), he includes and explains figures from previous classic works (i.e. Schneider, 1971) in order to describe migration from a fundamental ...
nate's user avatar
  • 796
6 votes
1 answer
760 views

How are the ZNE, ZRT and LQT coordinate systems defined?

I'm confused about the direction of Z (upward or downward?), R (outward or toward the source?) and T.
wsdzbm's user avatar
  • 243
5 votes
1 answer
116 views

What is the purpose of wavelet extraction from the seismic trace?

I would love to know what exactly we can do with the extracted wavelet. What kind of information extracted wavelet can contain?
Fearless_Wolf's user avatar
5 votes
2 answers
137 views

What percentage of the earth's surface is covered by 2D or 3D reflection seismic data?

It was recently asserted to me that we have no idea what Planet Earth really looks like below our feet. I responded that (mainly oil-industry) seismic data covers a vast area and so actually we have a ...
nickcrabtree's user avatar
5 votes
3 answers
1k views

Gaussian wavelet generation with a given frequency

How can I generate a Gaussian wavelet (time domain) with a given central frequency. I mean if I take the Fourier Transform then its spectrum should be around that given central frequency instead of ...
Amartya's user avatar
  • 347
5 votes
1 answer
167 views

Is there a seismic discontinuity between the lithosphere and asthenosphere?

I've been learning about seismic discontinuities, mainly the 5 defined ones - Conorod discontinuity, Mohorovicic discontinuity, Repetti discontinuity, Gutenberg discontinuity, and Lehmann ...
Sasikuttan's user avatar
5 votes
1 answer
1k views

Open source seismic refraction processing

What I am in search of is an open source tool to pick first arrivals, plot travel-time curves, and perform simple velocity modeling. I am experimenting with seismic refraction to identify shallow ...
MLR's user avatar
  • 51
5 votes
0 answers
58 views

How do I generate a Moho depth model from seismic refraction data?

There are several permanent seismograph stations in Eastern Canada that have been recording arrival times for over 25 years. Using refracted Pn arrival times from natural earthquakes I would like to ...
Alex Koldewey's user avatar
4 votes
1 answer
324 views

Seismic data spectral analysis

The two images below correspond to two processed seismic cross-sections. My question is this: why at/near 0 Hz is there "lots" of seismic energy still present? Most if not all of the lower end of the ...
nate's user avatar
  • 796
4 votes
1 answer
655 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 ...
shrey's user avatar
  • 1,489
4 votes
1 answer
215 views

wavelength of seismic wave with a gaussian source

I want to know how to get the wavelength/frequency of a seismic wave, if I only have a Gaussian source and the velocity (c = 4000m/s) of a medium given. e.g. for a Ricker wavelet it would be easy to ...
guest101's user avatar
4 votes
1 answer
208 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 ...
EMGeo's user avatar
  • 41
4 votes
0 answers
35 views

Seismicity associated with post glacial rebound

Allied to the question: Why is relative sea-level falling in Hudson Bay?, where the surviving answers mention post glacial rebound. Is seismicity associated with post glacial rebound and if so what is ...
Fred's user avatar
  • 24.7k
4 votes
0 answers
226 views

Beam forming FK analysis of a seismic wave

So after reading alot of literature on source localization, I found out that FK analysis is one of the most widely used methods to determine source location without explicitly calculating the ...
Sanika Khadkikar's user avatar
4 votes
0 answers
49 views

Seismic velocity inversion & analysis

I attended at talk recently at the TGS office in Houston, TX, by Marianna Raunch. During this talk, a statement was made that for "very large" velocity inversions, semblance (or other similar ...
nate's user avatar
  • 796
4 votes
0 answers
79 views

Seismic data acquisition: reliability of high-bandwidth data

In my research, finding and understanding info relating to the lower end of (conventional) surface seismic data acquisition (i.e. 15 - 1 Hz) is relatively simple. However, when I look at specs for a ...
nate's user avatar
  • 796
4 votes
0 answers
254 views

How to do inverse Fourier transformation with Seismic Unix?

I convert data from $t$-$x$ domain to $f$-$k$ domain to do dip filter using sudipfilt command. After that it should return to the $t$-$x$ domain. Which command ...
Liath Fahad's user avatar
4 votes
0 answers
206 views

Can non-antipodal Chicxulub impact seismic wave be connected to Rio Grande Rift and Laramide Orogeny?

I have conducted a brief survey of Internet sources and cannot locate any definite discussion of a possible connection between the Chicxulub impact and the inception or acceleration of the Rio Grande ...
Dalton Bentley's user avatar
4 votes
0 answers
80 views

Unwanted oscillations in Synthetic seismogram

I have generated a synthetic seismogram using FDTD elastic velocity-stress formulation on a staggered grid. I can't understand origin of oscillations modulating on seismogram. Is it a result of ...
Amartya's user avatar
  • 347
3 votes
1 answer
108 views

Predicting rock type from seismic processing

In reflection seismology, we create a source with an airgun and then use receivers to register acoustic waves (an approximation) at the surface. From these measurements, we can predict a velocity ...
TylerMasthay's user avatar
3 votes
2 answers
1k views

Travel Times for Seismic Wave Types - Why reflected t-x plot curves

I do not understand how the reflected wave in a seismic survey has a steepening slope (slows down) Please bear with me as I lay out my thoughts because I feel like I can grasp all of this except this ...
MattGeo's user avatar
  • 303
3 votes
1 answer
290 views

Which type of seismic sensors usually used in Earthquake Early Warning?

As I'm a newbie in seismology and related area, I would like to know which type of seismic sensors usually used in earthquake early warning systems?
Ehsan Maiqani's user avatar
3 votes
1 answer
2k views

Why do P waves have a higher velocity in the lower mantle than in the core even though the core has a much higher density?

I've just started teaching 9th grade Earth science and my students and I have noticed something about P and S wave depth vs velocity graphs. In the typical graph, eg: https://www.researchgate.net/...
Greg Walsh's user avatar
3 votes
2 answers
155 views

Is it reasonable to approximate the swinging building (base of the building) during an earthquake to a simple harmonic motion?

I am thinking of making a model of swinging building during earthquake and study the methods to minimize the swinging. So does it even makes sense to approximate the swinging buildings (the base of ...
shinigami's user avatar
3 votes
2 answers
2k views

Seismic dispersion: What does it really mean and what causes it?

Body waves (to some extent) and especially surface waves show dispersive characteristics during propagation. In Dr. Christopher Liner's book [Elements of Seismic Dispersion (2012)], this phenomenon is ...
nate's user avatar
  • 796
3 votes
1 answer
1k views

Detecting seismic waves using Software Defined Radio

I understand about physic and waves, but I am a totally rookie in this topic. I was wondering which are the typical frequency ranges of the S-waves, P-waves and surface waves. My idea would be to ...
Cod1ngFree's user avatar
3 votes
1 answer
358 views

Open source well information viewer

I am in the middle of a hobbyist experiment and would like suggestions on an open source HTML viewer for mud loggging, FMIs, lithology and seismic. I have used INT before but for this project I would ...
jerrychokes's user avatar
3 votes
1 answer
112 views

Wave train 200 m/s meaning

I ran a 60 m line intended for surficial seismic refraction. Energization with hammer. 12 (10 hz vertical 5 m spaced) geophones and 5 shots (15 m spaced). Record length 0.5 s. Thanks to a borehole ...
Carlos Javier's user avatar
3 votes
1 answer
335 views

Amplitude scaling in seismic inversion

I've been testing how amplitude scaling subsequently affects the results of gapped/non-gapped deconvolution and an impedance inversion algorithm called BLIMP (Ferguson and Margrave, 1996). Indeed, ...
nate's user avatar
  • 796
3 votes
0 answers
67 views

Difference between landslide waves and earth quake waves

I am new to this field, recently started working on landslide monitoring mainly in signal processing part. I have the following questions? 1.Will each land slide and every vibration have p wave, s ...
Abhishek's user avatar
3 votes
0 answers
52 views

Which wavelet for acoustic inversion?

If I have seismic data obtained with an explosive source (i.e. minimum phase wavelet), should I re-process the data into zero-phase data to perform an acoustic impedance inversion?
t_rex's user avatar
  • 31
3 votes
0 answers
116 views

The phase of a seismic source

There are different seismic sources for both land and marine acquisition surveys. Measuring the spectral characteristics (phase, frequency, amplitude, etc.) is a critical part of evaluating the ...
nate's user avatar
  • 796
2 votes
4 answers
4k views

Why is a mild earthquake often mistaken as dizziness or vertigo?

Is it due to the longitudinal nature of the seismic waves? When a heavy bus or truck goes by at high-speed, the shaking in nearby ground is not mistaken as dizziness, rather the feet and body feel a ...
user avatar
2 votes
3 answers
273 views

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 ?
Djabri Josef's user avatar
2 votes
1 answer
130 views

Seismic inversion: High-Frequency approximation

In numerous textbooks and papers, the phrase "high-frequency" approximation is used in regards to different types of seismic inversion. What exactly is meant by this? Also, what are the implications ...
nate's user avatar
  • 796
2 votes
1 answer
102 views

What is the vertical axis of this waveform shown in this tweeted IRIS GIF?

This IRIS tweet shows a video of siesmic waves from the recent M6.4 Earthquake in California rolling across the US. I've made a small GIF to give the idea but the "GIF" in the tweet shows the whole ...
uhoh's user avatar
  • 7,122
2 votes
2 answers
2k views

converting segd data to SU format using seismic unix

I tried to convert segd format to su format using seismic unix by below command: segdread tape=1.segd > 1.su but I have an error: ...
Nora11's user avatar
  • 21
2 votes
1 answer
94 views

Basic petrophysics

The following question was inspired by Effective pressure or what is the effect of presssure?, which may be accessed here: https://inside.mines.edu/UserFiles/File/CRA/2005/...
nate's user avatar
  • 796
2 votes
1 answer
227 views

What is trace-based seismic Inversion

Looking through different literature articles and books concerning seismic inversion - mostly post-stack - phrases like "trace-based" and "model-based" keep appearing. I know that model-based in when ...
nate's user avatar
  • 796