A 6.0mag EQ occurring in Tonga, 8700km distance is a better candidate than the 5.7 EQ in Miyako Japan (7400km) alog 19074, I looked at yesterday for evaluating Terramon.  Slightly further away but enough larger and it makes all the difference.  With the 5.7 EQ, I couldn't be sure there was anything on the seismos, the predictor estimated a velocity of 1.9um/sec for the R-wave.  For the 6.0 EQ, the estimate is 5.

The arrival at the site is clear on the ground STS2--see attached.  I've marked the 3 times from the predictor with thin lines and we clearly see the arrivals.  The P-wave arrival estimate is very good; the plot is 40 minutes long.  The S-wave arrival is 'late' tens of seconds and the surface wave arrives more than 5 minutes sooner than predicted.  These channels should all be calibrated in nm/sec

The second plot shows some GS-13 channels on the BS ISI stage2 and an IFO red power showing if the IFO is fully locked.  The Surface (R-phase) arrival (last arrival) does clearly change the motion on the GS13s--I've marked the apparent arrival of the Surface wave on the plots--the thicker line.  The two fat portions of the GS-13 signal correspond to locked DRMI periods, beginning and middle of plot.  So what can I say...

1) The arrival of this P-wave may have brocken the DRMI although it broke ~20+ seconds after arrival prediction.

2) Clearly, the DRMI can hold lock during the arrival of the S-phase: it arrived some 50 seconds after the middle DRMI lock section began.

3) This IFO lock break was not caused by the surface wave arrival: it broke ~6 minutes before the obvious surface waves hit-marked at thick line.

4) The DRMI did not lock while the Surface Waves had the BS GS13s rung up although later looks show the DRMI may not be soley resposible for the GS13 ring up.  Still need to understand better what the IFO state does to the ISI.  I've chosen BS GS13s as they are not in loop so maybe the most vulnerable.

5) The arrival velocity prediction is within a factor of 2 of that observed.