New Scientist Oct 3rd 2015 Page 12

"Deepest Quakes hit in Surprise Seasonal Cluster" -
true - not moon, but the Sun. And the Sun exerts about 1/7th of the tidal friction. Or to be more precise, 1/7th of the gravity variation cf Moon that we had to take into account when designing weighing machines of accuracies in the order of 1 part in 20,000. (beyond legal requirements but sometime we were asked). That was when I worked for W & T Avery of that trade.