<p>According to the equation for local magnitude calculation I give my answer: Of course there is a lot of algorithms for auto-picking, in fact, the magnitude value that you see in the first report (immediately) after an earthquake is (almost always) an automatic calculation. <a href="https://academic.oup.com/gji/article/199/1/368/731808" rel="nofollow noreferrer">https://academic.oup.com/gji/article/199/1/368/731808</a>. However, the P and S picked time is checked but humans in order to improve the accuracy. I think the human verification is always necessary and obligatory, because some earthquake are complex signals. <img src="https://i.sstatic.net/YQBD7.jpg" alt="seismogram showing some complex earthquake signal logs in Colombia">!. Moreover, the point here is not the human-based method, I thing it should be focused on the quality control system. </p>

CC BY-SA 4.0
2020-02-28T00:32:48.517Z
2020-02-28T00:32:48.517Z
Paul Goyes
<p>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 distance between P-S waves, and then measuring the height of the highest amplitude. Or are there software, APIs, and etc that can do this automatically by just providing the seismograph data. Or there's no way to calculate the Local Magnitude without a human input?</p>

CC BY-SA 4.0
2020-03-12T16:18:03.463Z
This procedure can be done automatically, but unanticipated errors will creep in. Usually, some binning/averaging is done to suppress these effects.
dvoytan
<seismology>
What are today's methods in calculating the Local Magnitude of earthquakes?
olivakyle
# What are today's methods in calculating the Local Magnitude of earthquakes?

(Asked by: username_0 on 2020-02-26)

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 distance between P-S waves, and then measuring the height of the highest amplitude. Or are there software, APIs, and etc that can do this automatically by just providing the seismograph data. Or there's no way to calculate the Local Magnitude without a human input?

**Tags:** seismology

> **Comments:**
> **username_1**: This procedure can be done automatically, but unanticipated errors will creep in. Usually, some binning/averaging is done to suppress these effects.  

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## 1 answers

### Answer by username_2 on 2020-02-28. Score: 1

According to the equation for local magnitude calculation I give my answer: Of course there is a lot of algorithms for auto-picking, in fact, the magnitude value that you see in the first report (immediately) after an earthquake is (almost always) an automatic calculation. <https://academic.oup.com/gji/article/199/1/368/731808>. However, the P and S picked time is checked but humans in order to improve the accuracy. I think the human verification is always necessary and obligatory, because some earthquake are complex signals. ![seismogram showing some complex earthquake signal logs in Colombia](https://i.sstatic.net/YQBD7.jpg)!. Moreover, the point here is not the human-based method, I thing it should be focused on the quality control system.


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