There seems to be a bit of confusion in this thread between differing seismic scales.
The Central Weather Bureau in Taiwan uses an intensity scale where a value of 2 means the event is noticeable by most people and 3 means some of those people are frightened.[0]
For example, here[1] is the recent report for this morning's "5-" event (#137), which I can assure you everybody in the office still felt in Taipei, where it was only a "2". This event also had a magnitude of 5.9 on the ML scale that is used internationally.[2]
Seismic magnitude and intensity are two different measures.
Magnitude measures the amount of energy released by the ground movement. It is a property of the earthquake and is independent of where the measurements are taken. When someone says 'a magnitude 7 EQ', this what they are referring to. Today, the Moment Magnitude scale is used, which is a better version of the Richter scale.[1]
Intensity is a measure of the effects of an earthquake in a particular location. Intensity is commonly assessed with the Modified Mercalli Intensity scale[2], which is a qualitative measure of how the shaking was felt and what damage was done. (As an aside, since it is qualitative, it is the starting point for assessing the size of historical earthquakes.)
You can see on the shakemap Taipei has an MMI of close to 4, which corresponds to: "Felt indoors by many, outdoors by few during the day: At night, some are awakened. Dishes, windows, and doors are disturbed; walls make cracking sounds. Sensations are like a heavy truck striking a building. Standing motor cars are rocked noticeably."
Coming back to this I understand now you were referring to Taiwan's own intensity scale and not some recalculated magnitude - my bad! Wanted to clear up that I wasn't dunking on Taiwan's measurements. Their own intensity scale is likely better tuned for the region.
You are confusing two different units. The earthquake moment magnitude scale measures the amount of energy of a given earthquake. It does not concern the location you are and the shacking you felt. Therefore, for this particular Taiwan earthquake, its magnitude is 6.9 regardless of the location.
The intensity scale on the other hand measures the amount of shaking for a given location. Naturally, the further you are from the epicenter, the lower the intensity will be.
It's quite confusing to have a couple of different numbers to "characterize" a quake: magnitude (in a few different systems), intensity scale (guess there are different systems around the world as well).
Really great to see the clarity here from knowledgable people on this! :) ;pxx ;p
This is not even an actually... The reviewed magnitude on USGS is 6.9 at the epicenter of course that's what I'm referring to. What are you even saying?
Magnitudes 6-7 were in the epicenter near Taitung, fairly far away - about 200-300km
Haha I'm well aware of that. I'm not saying that's not the case I'm saying in another comment that the shaking that I felt, I felt sickening. What you say doesn't contradict what I'm saying
Just disagreeing for the sake of it? Stupid and abusive.
Taiwan's weather bureau reports intensity in different regions and was reporting mostly 2 in Taipei (maybe at one point 3? esp. for New Taipei), that's what I'm talking about.
There was 2 quakes measured in taipei. The first one was 2, I didn’t feel it, was awake as it occured in the middle of the night and I was taking care of new born. The second was a 3 which I felt! Wife was scared, 4yo daughter didn’t notice it on the bed watching tv.
The Central Weather Bureau in Taiwan uses an intensity scale where a value of 2 means the event is noticeable by most people and 3 means some of those people are frightened.[0]
For example, here[1] is the recent report for this morning's "5-" event (#137), which I can assure you everybody in the office still felt in Taipei, where it was only a "2". This event also had a magnitude of 5.9 on the ML scale that is used internationally.[2]
[0] https://en.wikipedia.org/wiki/Central_Weather_Bureau_seismic...
[1] https://www.cwb.gov.tw/V8/E/E/EQ/EQ111137-0919-100745.html
[2] https://scweb.cwb.gov.tw/en-us/earthquake/details/EE20220919...