10:46:46.3 a.m. 3rd february 1931
The 1931 Napier Earthquake lasted for two and a half minutes and measured about 7.8 on the Richter Scale
a 7.8 earthquake. the plates irratated and caused a friction shake on the crust
New Zealand Navie
usually an earthquake occurs because underneath the earths crust are tectonic plates and when they move occasionlly one will get caught but the outside is still moving and that causes an earthquake