The quake, which measured 4.7 on the Richter scale, happened at 2:31pm around eight miles from Swansea in South Wales.
Swansea University in Wales was evacuated.
It's extremely rare that earthquakes strike in this part of the world, and when one does hit, it's never strong enough to cause much damage.
The British Geological Survey says a magnitude 4.4 quake has shaken southern Wales. At first, many weren't sure if they had experienced an natural disaster.
The British Geological Survey said on Twitter that an quake of that magnitude occurs in Britain about every two or three years.More news: Tim Arsenault: International incidentals on the Olympic ice
Play had to be stopped, with the club's Twitter account reporting: 'Temporary stop in play.
Twitter users reacted to the "earth moving" event. "The dogs are not happy at all though", she said.
A spokesman for the BGS said: "It was a reasonably-sized natural disaster".
Anne Jones, near Builth Wells, Powys, said the tremor "felt like a bomb had gone off, the whole house shook", while Barbara Watkin described a "rumbling noise" in Ceredigion.
But not everyone felt the earth move, with others complaining they had missed it.