Raw water column data were collected aboard RV SONNE during cruise SO312 using a Kongsberg EM 122 multibeam echosounder. The expedition took place during 2025-05-04 – 2025-05-31 from Auckland (New Zealand) to Auckland (New Zealand) in the South West Pacific. The project BRASS is designed around testing three fundamental hypotheses related to caldera formation and its relationship to hydrothermal systems. Data were recorded within the New Zealand EEZ. Sound velocity profiles (SVP) were applied on the data for calibration. Please see environmental data and the cruise report for details. The data are unprocessed and can therefore contain incorrect depth measurements (artifacts) if not further processed. Note that refraction errors may occur when no proper SVP is applied. Data acquisition was done by GEOMAR Helmholtz Centre for Ocean Research Kiel, provision of the data is supported by the DAM Project Underway Research Data and published according to the FAIR principles.

These data should not be used for navigational purposes.