Planetquake

But why should Jupiter and Saturn exercise such a particular influence on the earth when they attain these longitudes? M. Delauney answers that when in those longitudes the planets encounter meteor swarms, and just as earthquakes are rather numerous in November, when the earth passes through a meteor stream, so they reach a maximum when either of the planets undergoes the same experience. By strict parity of reasoning, it is planet-quakes that ought to ensue upon these conditions, not earthquakes; but to a bold theorist like M. Delauney that is a trifle.

There are devices that can determine the distribution of radioactivity over another planet from orbit; that can feel from the surface the faint rumble of a distant planetquake deep below; […]

Recurrent planetquakes would have made mining too hazardous, which could account for the Romulans' departure, but so could many things on this inhospitable world.