Taylor Swift fans took her “Shake It Off” musical advice literally last weekend, sparking seismic activity equivalent to a 2.3-magnitude earthquake at her concert in Seattle, seismologists say.

Western Washington University seismologist Jackie Caplan-Auerbach first examined the activity, which fans are dubbing a “Swift quake,” after she saw chatter in a social media group she monitors about Pacific Northwest earthquakes.

The Seattle concerts were played in front of a total of 144,000 fans over two nights.

Posting on Instagram afterwards, Swift said: “Seattle that was genuinely one of my favourite weekends ever. Thank you for everything. All the cheering, screaming, jumping, dancing, singing at the top of your lungs.”