This movement can be vertical, horizontal or a combination of the two. Movement of the rock masses along the faults can be felt as earthquakes – seismic waves that can result in extensive damage to the surrounding land, property and infrastructure from ground shaking. Damage can also be caused from faults that rupture and break the ground surface.
The Wellington region is seismically active. Compared to the rest of Aotearoa, our region has a higher probability of ground shaking occurring that causes damage to land, property or infrastructure.
Porirua is within an active part of the deforming boundary zone between the Australian and Pacific tectonic plates. There are three known active faults identified in Porirua. These are, from west to east:
Earth Sciences New Zealand (formally GNS Science and NIWA) maps known active faults in the New Zealand Active Faults Database (NZAFD). The NZAFD can be accessed on the Earth Sciences New Zealand here [link – GNS NZAFD map]
Fault avoidance zones have been identified for the three known active faults in Porirua. These are detailed in the report ‘Porirua District Fault Trace Study’ prepared by GNS Science in 2014, and available here. These are also used in the District Plan for managing subdivision, use and development that may be at risk from fault hazards.
