That quake occurred in the Central Virginia Seismic Zone. In part because seismic waves can travel further in East Coast sediment than along the much more seismically-active West Coast ...

Tina Dura (at far left) and her research team use geologic methods to reconstruct the seismic history of the coastal region in the Cascadia Subduction Zone. Disclaimer: AAAS and EurekAlert!

In addition to the Virginia earthquake, there were nine tremors in the area immediately around Cokedale, Colorado, near the border of New Mexico, the largest of which was a 5.3 magnitude.