The raw SeaSpy magnetometer data presented here were collected in the Southern Ocean (SO) as part of the ISOBatA PNRA project during the XXXVII and XXXVIII Italian Antarctic expeditions on board the icebreaker

Laura Bassi. The ISOBatA project (Italian Southern Ocean Bathymetry from consistent exploitation of opportunistic seafloor datasets in the Antarctic region and surrounding areas) aimed to improve the understanding of the Southern Ocean through a novel approach that systematically integrates the collection

of bathymetric and magnetometric data during the Laura Bassi voyages in poorly charted regions between the Macquarie Triple Junction – MTJ and the Emerald Fracture Zone n-EFZ.

This dataset spans two field campaigns (2021-2022 and 2023) collected through optimized navigation strategies, including reducing vessel speed during transits and following pre-planned corridors to enhance data quality and spatial coverage. The project was a collaboration between OGS (PI D. Accettella), UniMIB (A.

Savini), IGAG-CNR (M. Cuffaro) and INGV (F. Muccini).

The work was supported by the Programma Nazionale di Ricerca in Antartide - PNRA and benefited from the joint efforts of the Laura Bassi research teams on board.

Keywords: Southern Ocean, Bathymetry, ISOBatA, Laura Bassi, Antarctica, IBCSO.