Magnitude / Intensity.... what's the difference ?

I’m wondering… we hear about the magnitude of an earthquake, how’s that different from it’s intensity ?

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Thanks for asking ! This is actually a crucial question to understand earthquakes… and it’s all about whether you speak of the earthquake or of its effects !

Earthquake magnitude and intensity are both important measurements obtained after an earthquake. They refer to two different aspects of the seismic event, the size and the damage, but they are often confused with one another.

The magnitude is a number indicating the size of the seismic event. An earthquake has only one value of magnitude. Such a value is obtained by analyzing seismic signals. The more seismic signals are analyzed, and the more time is spent on the analysis, the more accurate the resulting magnitude value will be.

The intensity is a number (written as a Roman numeral) indicating the damage caused by an earthquake. An earthquake has several intensity values, because the shaking and the damages can vary from place to place depending on the distance from the epicenter. The intensity is calculated using human observations and reports of felt shaking and damage.

I hop this helps :nerd_face:

Why do we keep hearing in the media of the Richter scale for magnitude?
From the wikipedia page, it says it’s a local scale, unadapted and outdated, and that the moment magnitude (I guess it’s the one you’re referring to) if much better suited to compare earthquakes.

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  1. Magnitude is an Instrumental parameter while the intensity is an Observational parameters…
  2. Magnitude remains same with the distance on other hand intensity have inverse relation with the distance.
  3. Magnitude is amount of energy released during an earthquake but intensity is what human feel. :relaxed:

We often use Richter magnitude scale because it’s the most famous one…media often use that one.

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