Waterfalls Flashcards
What are waterfalls?
They are vertical drops that develop during the youth stage in the rivers course.
How are they formed?
Hard rocks e.g. granite lay on top of soft rocks e.g. sandstone while the river flows above the hard rock. The river erodes material drops down with the rivers hard rocks creating the vertical drops.
What creates the plunge pool?
The eroded material drops down with the rivers load creating the plunge pool (this is abrasion).
How does the the plunge pool get bigger?
Hydraulic action
How is the overhang created?
The water dropping down in the plunge pool splashes against the backwall of the waterfall with solution eroding it, undercutting it and creating an overhang.
How does the waterfall retreat upstream?
The pressure and force of gravity make the overhang eventually collapse and this process repeats itself, making the waterfall retreat upstream.
What is an example of a waterfall in Ireland?
Torc Waterfall near Killarney, Co. Kerry
