Distribution of present-day vertical deformation across the Southern Alps, New Zealand, from 10 years of GPS data

Abstract

We use ten years of GPS data from nine continuous and six semi-continuous GPS stations in a transect across the Southern Alps to measure rates of relative vertical movement with typical 1σ uncertainties of 0.3–0.5 mm/yr. The estimated vertical rates define a fairly smooth profile across the range, with the highest rates of ∼5 mm/yr found near the crest of the mountains and ∼20–30 km southeast of the Alpine Fault. The distribution of vertical rates supports models based on horizontal velocities from GPS surveys in which interseismic coupling on the Alpine Fault decreases from 100% near the surface to zero by 13–18 km depth.