A 3DQPAttenuation Model for All of New Zealand

Abstract

Online Material: Table of New Zealand-wide Q P and V P with resolution estimate; figure showing nonparametric curve fit Q P ( V P ). Over the last 13 years, we have developed 3D seismic attenuation models for many parts of New Zealand through individual regional studies using local earthquake data, often collected using regional temporary seismic networks. Most of New Zealand is seismically active, as illustrated by Figure 1a, which shows the distribution of earthquakes of magnitude≥4.5 for the 2001–2011 period. These earthquakes illustrate how convergence between the Pacific and Australian plates is accommodated in very different ways along the New Zealand plate boundary, from subduction of the Pacific plate under the Australian plate at the Hikurangi subduction zone in the North Island and northern South Island, to continental convergence in the central South Island, to steep subduction of the Australian plate beneath the Pacific plate in Fiordland in southwestern South Island. Figure 1. (a) Tectonic setting of the New Zealand region, showing earthquake epicenters for events of magnitude≥4.5 from the period 2001–2011; the 2 km bathymetry contour is shown offshore. The dashed box shows the extent of the defining New Zealand-wide grid, and the narrower box (solid lines) indicates the area shown in Figure 3. (b) Stations used in the QP inversions and areas of individual studies: A, northeastern North Island (Eberhart-Phillips and Chadwick, 2002); B, southern North Island (Eberhart-Phillips et al. , 2005); C, central–southern South Island (Eberhart-Phillips, Chadwick, et al. , 2008); D, central North Island (Eberhart-Phillips, Reyners, et al. , 2008); E, northern South Island (Eberhart-Phillips et al. , 2014). The locations of previous regional studies of 3D seismic attenuation are shown in Figure 1b. From north to south, these are Eberhart-Phillips …