Wednesday, April 3, 2024

Moderate subduction earthquake hits Taiwan


This is the expected 'every day' earthquake for Taiwan, at 'living memory' odds, or about 1 in 100.  

You can see by the underwater geology, that  a 'real' cleaning earthquake of 1 in 500, would rip the whole coast, and would be closer to M9.  This M7ish is in the upper corner, and has all the attributes of a foreshock.  The odds that this is a foreshock are 1 in 100, or the same odds of this earthquake happening in the first place.  This would play out in the next day or so, and then settle to the regional odds.

Taiwan is the world leader in monitoring for pgv, and listening to me (ha, ha).  However, I am guessing from the tilted building that the pgv is 40 cm/sec, and not 80, which would tip the buildings.  This is a Chile earthquake, and Taiwan should have ridden this out, like nothing happened.  Had they listened to me, they would have better foundations.

This is my scenario for Toronto, 40 cm/s, with tilted buildings all over the place.  The floppy condos will crack to pieces.  My brain seems foggy today because of the storm, so I can't dig into their strong ground motion records.  Anyway, the big excitement will be the chance of the M9 with 100 cm/s, and I'll wait for that.

ps.  the odds of 40 cm/s for Toronto are 10 times less, but the consequences are 10 times worse.  Thus, the 'seismic risk' is the same.  This article has become very popular lately.

ps the tendency to 'toss' anything rarer than living memory is what I call a 'handyman special'.  This thought controls all our infrastructure.  It is the reason you have fragile backup power plants, and block walls in nuclear plants.  The loud-mouth influencers will say 'We don't have earthquakes in Toronto' and they dominate everything.  That is why the bridge collapsed, since the odds of a big ship hitting the supports is just beyond 1 in 100.

ps and here is the art for today.

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