Part of the Hawkes Bay has been rattled by a series of earthquakes this morning.

GeoNet said the four tremors were all close to Porangahau at a depth of 20 kilometres or less.

The most powerful was a moderate strength magnitude 4 earthquake which struck just after 6am.

A 3.1 magnitude quake struck at 6.38am, a 2.5 magnitude quake at 7.32am and a 3 magnitude quake at 8.02am.