NZ Active Deformation

Project Leader: T/F

Velocity map

New Zealand is astride the boundary of the Pacific and Australian plates. In this objective we synthesise local measurements with global constraints to build up a national picture of the effects of plate boundary deformation. Vertical and horizontal deformation of the ground surface accumulates slowly across the width of the country every year, and occurs very rapidly during earthquakes. Geological structures record the accumulated deformation over much longer time intervals. We measure the present-day deformation and the results are used by Land Information New Zealand to define the national survey datum. The data is an important new input that may improve estimate of the national distribution of seismic hazard. The combined effects of vertical land movement and sea level rise will soon be determined sufficiently accurately in this objective for them to be useful in planning coastal development and sustainability. Finally, the stresses that are related to this deformation affect any type of deep drilling activity or fluid flow in the crust. This is particularly significant for petroleum exploration and exploitation.


  • GPS Deformation:Using GPS measurements to build an accurate picture of how surface deformation has occurred over the last decade.
  • Models & Stress (Susan Ellis): Modelling stresses and strains developed in the crust as a result of earthquakes, volcanoes, and distributed deformation in New Zealand
  • Sea Levels: Using continuous GPS to measure land uplift or subsidence near tide gauges at key points around the country to accurately estimate long-term sea level change.