A Snapshot of New Zealand's Dynamic Deformation Field From Envisat InSAR and GNSS Observations Between 2003 and 2011
Ian Hamling, Tim Wright, Sigrún Hreinsdóttir, Laura Wallace
Abstract
Abstract Measuring the deformation at the Earth's surface over a range of spatial and temporal scales is vital for understanding seismic hazard, detecting volcanic unrest, and assessing the effects of vertical land movements (VLMs) on sea level rise. Here, we combine ∼10 years of Interferometric Synthetic Aperture Radar (InSAR) observations from Envisat with interseismic campaign and continuous GNSS velocities to build a high‐resolution velocity field of New Zealand. Exploiting the horizontal GNSS observations, we estimate the vertical component of the deformation to provide the VLM for the entire 15,000‐km‐long coastline. The estimated vertical rates show large variability around the country as a result of volcanic, tectonic, and anthropogenic sources. Interseismic subsidence is observed in Kaikoura region supporting models of at least partial locking of the southern Hikurangi subduction interface. Despite data challenges in the mountainous regions from landslides, sediment compaction, and glaciers, InSAR data shows localized uplift of the Southern Alps.