Earthquakes are always unnerving. But for some, the aftershocks can go on beyond the actual tremors: People can experience anxiety, sleep problems and other health issues in the hours and days after a quake.

One such effect is a sense of dizziness after an especially large or frightening earthquake. In Japan, this feeling is called jishin-yoi (which roughly translates to "earthquake drunk,” or "earthquake sickness”). It is also sometimes called post-earthquake dizziness syndrome. Others might report experiencing "phantom” earthquakes that might feel like subtle aftershocks, or like the room has started shaking again, but this is in fact purely psychological.

There is very little research into these phenomena, and most of it has been done in the wake of earthquakes far larger than the one that jolted the U.S.' Northeast on Friday.