<p>I was told that </p>

<blockquote>
  <p>Seismic moment is determined by the observed spectral levels of the receiving waves.</p>
</blockquote>

<p>But I don't quite understand what it means.</p>

<p>How is this done in practice? Do you need anything in addition to a seismogram to infer the seismic moment value (like elastic material parameters)?</p>

CC BY-SA 3.0
2017-12-01T06:30:51.963Z
Traditionally it was done by looking at the amplitudes of the body and surface wave arrivals. Nowadays it is usually done by full waveform inversion - i.e. matching synthetic seismograms to the observed ones in an inverse problem.
bon
CC BY-SA 3.0
2017-12-01T11:17:22.453Z
@bon thanks! do you know what kind of models are used to create synthetic seismograms? do they rely on material parameters in some way?
ye-ti-800
CC BY-SA 3.0
2017-12-10T17:14:04.100Z
Yes you basically solve the wave equation, or some simplified version of it, in an medium with the properties of the Earth. I'm don't really know much more than that though because it's not my field.
bon
<geophysics><earthquakes><seismology>
How to calculate seismic moment from seismograms?
ye-ti-800
# How to calculate seismic moment from seismograms?

(Asked by: username_0 on 2017-11-30)

I was told that

> Seismic moment is determined by the observed spectral levels of the receiving waves.

But I don't quite understand what it means.

How is this done in practice? Do you need anything in addition to a seismogram to infer the seismic moment value (like elastic material parameters)?

**Tags:** geophysics, earthquakes, seismology

> **Comments:**
> **username_1**: Traditionally it was done by looking at the amplitudes of the body and surface wave arrivals. Nowadays it is usually done by full waveform inversion - i.e. matching synthetic seismograms to the observed ones in an inverse problem.  
> **username_0**: @username_1 thanks! do you know what kind of models are used to create synthetic seismograms? do they rely on material parameters in some way?  
> **username_1**: Yes you basically solve the wave equation, or some simplified version of it, in an medium with the properties of the Earth. I'm don't really know much more than that though because it's not my field.  

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## 0 answers

