SONNE 80a was a multidisciplinary expedition to map and sample intraplate volcanic activity associated with the proposed Easter "hotline" and its relation to the Orongo Transform Fault. The main objectives of the cruise were: 1) to study the area between Easter island, the Orongo Transform Fault and the East Pacific Rise (EPR), in particular to examine the relationship between near-spreading axis and true intraplate volcanic processes. 2) to study the Orongo Transform Fault (probably a "leaky transform") which forms the southern boundary of the of the Easter microplate, to determine to what extent it is involved in the Easter "Hotline" volcanism. 3) to examine the proposed extension of the Easter "hotline" to the west of the EPR in the direction of Henderson, Ducie and Crough Seamounts.

From 1983 until 1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions. At the time it was the most extended data compilation on ferromanganese deposits world wide. Initially published in a proprietary format incompatible with present day standards it was jointly decided by AWI and NOAA to transcribe this legacy data into PANGAEA. This transfer is augmented by a careful checking of the original sources when available and the encoding of ancillary information (sample description, method of analysis...) not present in the NOAA-MMS database.