Monday, November 14, 2016

New Zealand Rock and Soil Difference

Going through the NZ plots is giving me a headache.  Obviously, they like to keep their secrets.  I found two plots with very high accelerations for the pgv.  This means they are on rock, unlike the earlier ones I showed which are on soil

Such clean signals, no complexity in the mechanism here, no double event.  So although you might expect damage at 0.2g, the pgv is low, so no damage.  Until I see maps, I'll never prove this, but I'll bet they'll have no correlation with pga and damage.  Only pgv will work.  Smart people know this, but lots don't.

ps.  the earthquakes are marching up that hidden fault.  Next one a bit higher.  A few more, then the m9, but maybe in 30 years.

pps.  This is Wellington on soil

Note, the longer displacement plot - lots of low frequencies.

ps3 - a station on the middle of the fault hit 1.2g but no pgv yet.  Most likely on rock.

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