Could some building crack please explain to me how to understand NZ earthquake zones (according to NZS 3604:2011, Figure 5.4)? There are four zones, Zone 1, Zone 2…., but I can’t find any explanation on these zones, such as low, medium, high…
Northland including Auckland and Tauranga and down to Wellington are in Zone 1, as is the coastal slice down from the Banks Peninsula (including ChCh?) to Invercargill in the South Island and Stewart Island.
Wellington and the Banks Peninsula being known high-risk areas, I am tempted to interpret Zone 1 as the highest-risk zone. However, I am not sure because it also includes Auckland and Northland, which do not come to the top of my mind as highly earthquake prone areas.
Does this mean, for bracing purposes in timber-framed buildings, that all areas in Zone 1 are to be braced to the highest possible impact?