As a New Zealander and a retired journalists as well as a very keen quake follower for the past 11 years I would like to say all the recent quakes (and there actually have only been three very large ones (not four) were a very long way out in the ocean. The first was about 200 k's off the East Coast of the North Island and the other two , a 7.2 and an 8.1 were about 1000 k's North of NZ. Yes we do have many many quakes on land but these large ones were not. There have been dozens and dozens of aftershocks. Yes they were both on shelves underwater.