Text to post on Zenodo

New Zealand Wide model 2.2 seismic velocity and Qs and Qp models for New 
Zealand

Donna Eberhart-Phillips,  Stephen Bannister,  Martin Reyners,  Stuart Henrys

New Zealand Wide model 2.2 has a seismic velocity model for New Zealand 
developed from local-earthquake tomography studies. It is updated, from 
nzwide2.1 (zenodo.org/record/1043558), to incorporate results from the 
western North Island (Eberhart-Phillips and Fry, 2017) and the southern 
Hikurangi Cook Strait region (Henrys, et al., 2020). The Cook Strait results 
were interpolated and merged into the NZwide model and then additional 
inversion including some Kaikoura aftershocks was carried out to assure the 
model is appropriate for regional use. 

The Qp model 2.2 is updated from Qpnzw1 (Eberhart-Phillips et al., 2015), to 
incorporate results from the eastern North Island (Eberhart-Phillips et al., 
2017) and southern South Island (Eberhart-Phillips et al., 2018).

There has not been New Zealand wide Qs coverage until this year, and the 
NZwide 2.2 Qs model is the first complete Qs model. We are using the version 
name 'nzw2.2' to denote all the seismic property models since many 
applications require all the parameters. The Qs model 2.2 incorporates 
results from the eastern North Island (Eberhart-Phillips et al., 2017), 
western North Island and mantle wedge (Eberhart-Phillips et al., 2020), 
northern South Island (Eberhart-Phillips et al., 2014), and southern South 
Island (Eberhart-Phillips et al., 2018).

The models are provided in tables, where the Spread Function (SF) shows the 
resolution, such that where SF<4, there is little information. 
vlnzw2p2dnxyzltln.tbl.txt
Qpnzw2p2xyzltln.tbl.txt
Qsnzw2p2xyzltln.tbl.txt

There are also simul format velocity and Q files.
vlnzw2p2.mod.txt
Qpnzw2p2.mod.txt
Qsnzw2p2.mod.txt

And map plots with white lines denoting limits of adequate data.
mapvpvpvsnzw2p2.pdf
mapQpnzw2p2.pdf
mapQsnzw2p2.pdf

Velocity and Q at any point within the 3D gridded models are defined by 
linearly interpolating between nodes.
The models use Transverse Mercator coordinate transformation with a central 
meridian= 173, and counterclockwise rotation of 140.  Earth-flattening 
transformation is used for velocity during ray-tracing. The depths are 
relative to sea-level. Density has been included in the velocity table, by 
using an empirical relationship (Gardner et al., 1974; Hill, 1978).

References:

Eberhart-Phillips, D., S. Bannister, and M. Reyners (2017), Deciphering the 
3-D distribution of fluid along the shallow Hikurangi subduction zone using 
P- and S-wave attenuation, Geophys. J . Int., 211, 1032–1045, 
doi:doi.org/10.1093/gji/ggx348.

Eberhart-Phillips, D., S. Bannister, and M. Reyners (2020), Attenuation in 
the mantle wedge beneath super-volcanoes of the Taupo Volcanic Zone, New 
Zealand, Geophys. J. Int., 220, 703-723, doi: 10.1093/gji/ggz455.

Eberhart-Phillips, D., and B. Fry (2017), A new scheme for joint surface wave 
and earthquake travel-time inversion and resulting 3-D velocity model for the 
western North Island, New Zealand, Phys. Earth and Plan. Int., 269, 98–111, 
doi:10.1016/j.pepi.2017.05.014.

Eberhart-Phillips, D., M. Reyners, and S. Bannister (2015), A 3-D Qp 
attenuation model for all of New Zealand, Seis. Res. Lett., 86, 1655-1663, 
doi:10.1785/0220150124.

Eberhart-Phillips, D., M. Reyners, P. Upton, and D. Gubbins (2018), Insights 
into the crustal structure and tectonic history of the southern South Island, 
New Zealand, from the 3-D distribution of P- and S-wave attenuation, Geophys. 
J . Int., 214, 1481-1505, doi:10.1093/gji/ggy194.

Eberhart-Phillips, D., S. Bannister, and S. Ellis (2014), Imaging P and S 
attenuation in the termination region of the Hikurangi subduction zone, New 
Zealand, Geophys. J . Int., 198, 516-536, doi: 510.1093/gji/ggu1151.

Gardner, G. H. F., L. W. Gardner, and A. R. Gregory (1974), Formation 
velocity and density - the diagnostic basics for stratigraphic traps, 
Geophysics, 39, 770-780.

Henrys, S., D. Eberhart?Phillips, Bassett, D., Sutherland, R., Okaya, D., 
Savage, M., et al. (2020), Upper plate heterogeneity along the southern 
Hikurangi Margin, New Zealand, Geophys. Res. Let., 47, e2019GL085511., 
doi:10.1029/2019GL085511.

Hill, D. P. (1978), Seismic evidence for the structure and Cenozoic tectonics 
of the Pacific Coast States, in Cenozoic Tectonics and Regional Geophysics of 
the Western Cordillera, edited by R. B. Smith and G. P. Eaton, pp. 145-174.