THE VIKINGS WHO VANISHED FROM GREENLAND
Isolation amplifies ordinary problems.
That may be why the disappearance looks so mysterious.
There was no single event to record.
Instead, the colony may have slowly slipped out of the practical world of Europe.
And when a society becomes peripheral enough, its disappearance can occur without anyone outside immediately realizing what has happened.
The disappearance of regular shipping would have affected more than luxury goods.
It could have changed information flow.