A M7.2 thrust/reverse slip earthquake occurred 1 minute 54 seconds before a M6.7 quake just offshore west coast Honshu. The latter quake had a fatality, injuries, and substantial damage according to a news article. The link is to the USGS quake page, in case anyone wants to figure out how long it would take the P wave to get from the first quake to the second. Use 8 km/s. I suppose there should be some range in time, as a M7.2 might be rupturing for 20 or 30 s, generating P and S and other waves. The last time I made a post like this was a month or 2 ago for a quake in the Carribean islands followed by one near Puerto Rico: but the Puerto Rico quake was removed from the list, no doubt because it did not occur. Today, it is very likely that the quakes both did occur...it has been long enough and they have focal mechanisms etc.

I'll give some credit to Lowell Whiteside, whose Ph.D. comps paper at U CO in 1990 was on seismic wave triggering over great distances, back when seismologists would not generally believe this.
Chris

• USGS quakes