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by haylem 3061 days ago
I disagree. The OP pointed to the perfect source for his title, showing the origin of the data.

The Richter scale measures and describes impacts, so you already know the impact from the 6.4 rating itself.

For 6.0 to 6.9:

> Damage to a moderate number of well-built structures in populated areas. Earthquake-resistant structures survive with slight to moderate damage. Poorly designed structures receive moderate to severe damage. Felt in wider areas; up to hundreds of miles/kilometers from the epicenter. Strong to violent shaking in epicentral area.

Also, your link added very little info, and the only mention of the building toppling (the infamous impacts) are in the title, with no reports, photos, or witness accounts (as of yet).

I like that the OP didn't fall into voyeurism, that the title was enough to inform me that a strong earthquake happened in Taiwan, and that the source was enough to confirm it.

For the rest, I'll have the evening news, or BBC articles, but I don't think I need them here on HN or that they were needed for this particular piece of information, at this point in time.

4 comments

Every countries and even regions building practices are different and will be affected differently. Even the distribution of new vs old buildings will take part in how much damage is actually done. USGS doesn't have any of that info and it's just as important as the power of the event itself.
Yep - a 6.4 in central Italy with lots of old stone buildings would be very deadly. In Japan, it'd do much less damage.
The Richter scale measures and describes impacts, so you already know the impact from the 6.4 rating itself.

I'm sorry, this is not quite true. The Richter scale measures the amplitude of seismic waves; the description you highlight is what might be expected generally, but doesn't give us any indication of the actual on-the-ground impact that any particular quake might have.

You're right, and my grammar was indeed incorrect: I did not mean to say that it measure the impacts but instead that it measures the amplitude of the quake, and also describes the impacts (which may or may not originally be true, but is how I've always seen it taught in classrooms, at least where I'm from). I guess I did remember it being closer to the model of the Beaufort scale for wind strength (which is more about the description than an actual measure of speed, originally).

And of course it does not give a precise description of the actual impacts for a given event, but I don't think it's generally far off the bat. But I'm no seismologist.

It doesn't measure the impact. For instance, 7.0 earthquakes can have a vastly different effect depending on the depth of the epicenter, the length of the earthquake, proximity to populated areas, proximity to faults.

EG:

https://apnews.com/d4217c33c5124972845022441d69728c

> The Richter scale measures and describes impacts, so you already know the impact from the 6.4 rating itself.

This is moment magnitude, not Richter. Specifically, 6.4 "Mww", or "Moment magnitude derived from a centroid moment tensor inversion of the W-phase", whatever that means. [1]

[1] https://earthquake.usgs.gov/earthquakes/eventpage/terms.php

pedantry: technically the USGS doesn't use the Richter scale anymore

Anyway: exactly how much damage an earthquake does varies wildly with exactly where it hits and what sort of shaking it produces and what time of day it is and the technical data doesn't always capture it perfectly. You can't know whether buildings actually did collapse (and were there people inside? how many?) without actual reporting.

Also geology is very important. Bedrock vs landfill will significantly affect impact. Marina distract vs Laurel Heights.
The USGS data clearly tries to make intelligent guesses in that direction (they try to guess at shaking, and local population, and local building standards, etc to predict the damage) but imho what matters is what actually happened rather than what the USGS computers think could have happened, and reports of building collapses are probably more "real" than whatever the USGS thinks is likely.
True, but I was also hinting at the fact that the other reported article does not really provide much in terms of reporting.

Also, this is HN: pedantry is built-in. Not saying it's a feature, but I guess it was a manufacturing defect I've gotten accustomed to. I don't mind. To each to have their own filter :)