Key Points:

An earthquake measuring five on the Richter scale has shaken the coastal area of Kaikoura.

The quake struck at 10.40, 20km east of Kaikoura and had a focal depth of 50km.

Co-owner of the Hapuku Lodge Justin Wilson said he grew up in San Francisco and had been in some big quakes and this was one of the biggest.

"It was a jolt, rather than a rolling quake. It lasted five or ten seconds, stopped for the equivalent amount of time, and then there was a second jolt of five seconds," Mr Wilson said.

Diane St Claire from the bi-lingual Ngai Tahu Hapuku School said the quake was big enough that the junior teacher brought her list of pupils to the staff room.

"There was no damage but it shook all right," Ms St Claire said.

The quake had attracted over 130 reports to the GNS website less than an hour after it struck.