Did today's Seattle earthquake damage my clocks?


We had a magnitude 6.8 earthquake today and boy did we feel it! Everyone's ok. There was no telephone, internet, or power loss at my lab in Bellevue and all the clocks kept running. The only "damage" I saw was some gear, once neatly stacked to the ceiling, came within an inch of falling down. That'll teach me.

As for the clocks here are phase plots for three of them for two hours on either side of the 10:55 AM quake.

The first plot is raw 1 PPS phase comparison data between a Kvarz CH1-76 Passive Hydrogen Maser and a HP 5071A Cesium standard. It doesn't look like anything significant happened during the quake. The 1 ns excursions during lunch might have been when I was moving around in the lab looking for anything out of place.

The second plot is a FTS/Datum 4065B Cesium against the same HP 5071A. Same conclusion.

The lab moved

Below is a CWU plot of earth movemement across Western Washington as a result of the February 28th Nisqually earthquake. My lab (look for site TVB1 near the center of the plot) moved about 8 mm to the south west according to the map vectors.

Below is a position plot showing the sudden discontinuity on the day of the quake.

More links

Seattle earthquake GPS modeling



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