I wonder if the river went dry first, like the water receding off into the horizon before a tsunami?
It is possible if you consider madaxe_again's theory(comment here). If the debris just started descending without interruption, there would be no receding.
alt Hacker News
It is possible if you consider madaxe_again's theory(comment here). If the debris just started descending without interruption, there would be no receding.