As can clearly be seen, the South Pacific
Ocean, particularly its eastern region, is one of the least explored
regions of the world ocean. South of 20◦ S from the
date line to 90◦Wit is possible to identify individual research
expeditions in the data distribution. Standard deviations are
generally higher in regions of higher data density, but the correspondence
is not followed throughout; in the Tasman Sea
the highest data density is found along the Australian shelf,
while the largest standard deviation is located north of New
Zealand, suggesting that the meeting zone of the two AAIW
varieties is a region of increased spatial and temporal variability.