Multibeam bathymetric data from Fiordland, New Zealand

R/V Tangaroa voyage Data TAN0305 and TAN0405 Not to be used for navigational purposes. Shipboard multibeam bathymetry data were acquired from the offshore Fiordland continental margin and from within Milford, George and Thompson-Bradshaw Sounds, New Zealand, by the former National Institute of Water and Atmospheric Research (NIWA; now Earth Sciences New Zealand). These data were acquired during R/V Tangaroa voyages TAN0305 and TAN0405 in 2003 and 2004 using a hull-mounted Kongsberg EM300, 30 kHz multibeam system. The objective of the surveys was to provide seafloor geomorphic data from the offshore continental margin to support ongoing studies of active tectonics. The data from Milford and George sounds were acquired to support related studies of fiord evolution, former glaciation and post-glaciation sedimentation history. These voyages were funded by the New Zealand Government via research funds granted through the former Foundation for Research Science and Technology (now the Ministry of Business, Innovation and Employment (MBIE) Strategic Science Investment Fund) Contract CO1X0203. The bathymetry data were processed using C&C Technologies HydroMap and ArcInfo Software, and utilised AML SVplus sound velocity profiles. Vessel positioning was provided by Differential GPS and POS/MV. During survey acquisition, the data collected were cleaned at the end of each line, gridded and binned. The processed data from the continental slope are gridded at a 25 m cell size. Data from the northern continental shelf and from Milford, George and Thompson-Bradshaw Sounds are binned at 5 m. All bathymetry data are referenced to Mean Sea Level (MSL). These processed data have been used in a number of published research studies including Barnes (2009), Barnes et al (2013), Barnes et al (2016a, b), Strachan et al. (2016), and Unland et al. (2025). The Milford Sound data were used by Dykstra (2012) in an unpublished study of rock avalanche hazards and risk. Acknowledgements: We thank the captain, crew and the following geotechnical personnel for their contributions to data collection and processing onboard R.V. Tangaroa voyages TAN0305 and TAN0405 in 2003 and 2004: John Mitchell, Miles Dunkin, Andy Hill, Steve Wilcox, Mike Stevens, Richard Garlick, and Peter Gerring. List of files Text Information file of the Zenodo Dataset (PDF) Figure 1. Overview map showing the extent of bathymetric grids acquired during research voyages TAN0305 and Tan0405. ZIP folder containing the following: Three processed multibeam bathymetric tifs from the continental margin at 25 m cell size · Doubtful_25m · Dusky_25 m · Milford_25 m Three processed multibeam bathymetric tifs from Milford, George and Thompson-Bradshaw Sounds at 5 m cell size · Milford Sound: milford_ s_5m · George Sound: george_s_5m · Thompson-Bradshaw Sound: thom_brad_5m