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Questions tagged [seismology]

For questions about the study of earthquakes and various seismic sources.

Seismology is the scientific study of earthquakes. Earthquakes have various source mechanisms (tectonic, volcanic, or even artificial mechanisms such as explosions) which all produce elastic waves that propagate through Earth's materials. Those waves are recorded by seismometers and the data is used to characterize earthquakes (location, magnitude, etc.).

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Seismic attenuation in mixed gas/water

Imagine I set off an airgun in the ocean and I measure the far-field signature. Then I do the same thing shortly after introducing tiny gas bubbles into the water, and mixing them well. Are there measurements of the Q factor for the mixed phase?
barry east
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Earthquake probabilities

A recent report estimated the probability of an earthquake greater than magnitude 7 on the southern section of the San Andreas fault at approximately 60% over the next thirty years. How is that probability calculated?
Daijohn
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What are today's methods in calculating the Local Magnitude of earthquakes?

I'm no expert and barely have any idea about this. But I want to know if the methods in calculating the Local Magnitude can only be done manually? I mean manually by first reading a seismograph, identifying the distance of the epicenter using the…
olivakyle
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Rayleigh waves generation

Good day, I do not fully understand the physical mechanism of formation of Rayleigh waves at the free surface. While their derivation is quite clear and obey free-boundary conditions, it is not clear their physical mechanism. Could you please…
Nikkey_love
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Why core refracted phases like SKS polarise vertically when P to S conversion happens in the Core-Mantle boundary?

While working on investigation of seismic anisotropy I came to know that core refracted phases like SKS or SKKS polarise vertically when P to S conversion happens in the Core-Mantle boundary. Why is the S wave in this case always polarised…
Ritwik Mandal
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Small earthquake happening every night at the exact same time

I experience this weird feeling for the last three months. Every night, at exactly 3AM I can feel small earthquake and I could not find anything on the internet related to it. Does anyone have any information about this. Edit. I live in Europe,…
echo6667
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equivalent body force

I am currently reading "Introduction to seismology second edition, and I can't wrap my head around earthquake sources, especially equivalent body force. What is an “equivalent body force” and how is it justified? Are there any examples of…
Rim Sleimi
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Is the centre of Italy still at risk of earthquakes?

I am working on a project which involves taking over a business based in Italy. It is a small village situated near Rieti (Sabina Hills) called Casperia and I am wondering if it is on a fault line? Is there a risk of having more quakes in the centre…
Adeline Poussin
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Tasmanian earthquake patterns

While researching across the Australian Earthquake Engineering Society archive about Seismology, I came across an earthquake map of the Australian island state of Tasmania (below): I am aware that Australia experiences intraplate earthquakes, so I…
user6341
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How can the focal mechanism of an earthquake be determined from P-wave polarity?

I have data of P-wave polarity related to an earthquake. I tried to find the focal mechanism from the azimuth, takeoff angle, and P-wave polarity. I found that two packages, FOCMEC and HASHPY, are used, but I cannot get them to run properly. Is…
Bishal Das
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