Unlocking the secrets of slow slip using next-generation seismic experiments (Slow Slip)

The NZ3D-FWI project aims to image the Hikurangi subduction zone (upper and lower plates and plate boundary fault) along the north Hikurangi margin, New Zealand where shallow slow slip events occur. The primary aim of the project is to collect data optimally to produce high-resolution active-source seismic velocity models using Full-waveform inversion (FWI). This deployment was part of a much larger experiment involving the collection of offshore 3D seismic reflection data and the deployment of 99 Ocean Bottom Seismographs. The onshore NZ3D-FWI deployment covered a 15 x 30 km area and included 49 CMG-6TD broadband seismometers from GEF deployed from December 2017 to October 2018, which detected airgun shots from the 3D seismic reflection survey and local and teleseismic earthquakes over the 9 month period. 119 short-period DATACUBE3 instruments loaned from GIPP Potsdam and 25 short-period GSX3 instruments from the Earthquake Research Institute (ERI), Tokyo were also deployed onshore between December 2017 and February 2018. The full NZ3D-FWI experiment is described in detail in: Bell R, Gray M, Morgan J, Warner M, Fagereng A, McNeill L, Jacobs K, Henrys SA, Fry B, Watkins S, Lacey H, Black JA, Lane V, Daly D, Lindsay D, Bangs N, Arai R, Kodaira S, NZ3D-FWI team. 2019. New Zealand 3D full waveform inversion (NZ3DFWI) 2017-2018 field acquisition report. Lower Hutt (NZ): GNS Science. 79 p. (GNS Science report; 2019/71). doi:10.21420/ZZ8R-QR04 This dataset contains only data from DATACUBE3 instruments (onshore). Data conversion was done with GIPPtools (Lendl, C. (2024). GIPPtools (2024.354). Zenodo. https://doi.org/10.5281/zenodo.14524955). All station metadata were taken from Bell et al., 2019, Table Table A4.1 in Appendix 4. Exceptions: station EC09: Sensor orientation and geophone serial number were not recorded and set to 0 and 999, respectively. Station EC10: Sensor orientation was not recorded and set to 0. Station EC04: Station elevation was not recorded and set to 33.0. Station DC71: sensor orientation was not fully recorded and set to 5°E. Some sensors were misoriented; azimuths are contained in the metadata; in case of misorientation larger than 15°, channel orientation codes 1 and 2 were used instead of N and E. Waveform data is available from the GEOFON data centre, under network code 3Q.