Aftershock to M3.1 quake

It looks like there was an aftershock to Tuesday's M=3.1 quake south of Colorado City in northern Arizona. At 5:42 PM local time there was a magnitude 2.8 quake at about the same location. Technically it qualifies as an aftershock to the larger, preceding event.

[Right, location of aftershock - star - and historical seismicity in the region. Credit, USGS]