We’ve mapped the whole ocean up to a certain resolution (5kms iiirc). This mapping allowed us to spot where the potential really low spots are, we scanned those particular low spots with higher resolution and from there we found which is the lowest.
It is possible that there is a particular place that for some reason goes really really deep but everything around it is not that deep so it doesn’t show up in our low resolution sweep, but it’s not really likely (there’s also not much to gain for going on a wild hunt for this theoretical place that probably doesn’t exist)
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