I've been running an experimental record on a Fedchenko Clock which is a
very precise  Russian pendulum clock Ca 1960. The clock has a very high Q -
the pendulum runs in a tank at 6mm pressure - and I noticed that on
Saturday Morning at approximately 6:04am EDT there was a substantial change
in the clock rate. When I checked my seismometer records for the period, I
saw a powerful surface wave arriving at the same time and lasting for about
6 minutes. It caused a rate change of about 2ms which is really very large
for the clock. I've put a record of the clock rate up showing the rate
before, during and after the quake as well as the Winquake record showing
the arrival here in Oakland, NJ. I'm embarrassed to say that the Winquake
record is off by about 5 minutes because I haven't set the computer clock
in a couple of months. The clock graph starts at 5:59 EDT and the first
disturbance is at 6:03:28 EDT. Although it is known that earthquakes can
stop clocks, I'm all the way over on the east coast thousands of miles away
and I don't think it has ever been shown before that a precision clock can
change rate under these circumstances.
Bill S

The clock (Microset) graph is 

The Winquake graph is 


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