Shear wave velocity variation across the Taupo Volcanic Zone, New Zealand, from receiver function inversion

• Published in: Geophysical journal international Vol. 159; no. 1; pp. 291 - 310
• Main Authors: Bannister, S., Bryan, C. J., Bibby, H. M.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.10.2004; Blackwell Science Ltd
• Subjects: crustal structure; receiver functions; Taupo Volcanic Zone; waveform inversion
• ISSN: 0956-540X; 1365-246X
• DOI: 10.1111/j.1365-246X.2004.02384.x

The Taupo Volcanic Zone (TVZ), New Zealand is a region characterized by very high magma eruption rates and extremely high heat flow, which is manifest in high-temperature geothermal waters. The shear wave velocity structure across the region is inferred using non-linear inversion of receiver functions, which were derived from teleseismic earthquake data. Results from the non-linear inversion, and from forward synthetic modelling, indicate low S velocities at ∼6–16 km depth near the Rotorua and Reporoa calderas. We infer these low-velocity layers to represent the presence of high-level bodies of partial melt associated with the volcanism. Receiver functions at other stations are complicated by reverberations associated with near-surface sedimentary layers. The receiver function data also indicate that the Moho lies between 25 and 30 km, deeper than the 15 ± 2 km depth previously inferred for the crust–mantle boundary beneath the TVZ.