how are waterfalls formed?
Waterfalls are commonly formed when a river is young. At these times the channel is often narrow and deep. When the river courses over resistant bedrock, erosion happens slowly, while downstream the erosion occurs more rapidly. The rock in the upper-course of the waterfall in harder than the bottom of the waterfall which is softer. Over time the soft rock will erode and form a plunge pool. After this has occurred the hard rock will collapse into the plunge pool and the process starts all over.
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There are many different types of waterfalls. Examples are:
- Ledge Waterfall: Water descends vertically over a vertical cliff, maintaining partial contact with the bedrock.
- Block/Sheet: Water descends from a relatively wide stream or river.
- Classical: Ledge waterfalls where fall height is nearly equal to stream width, forming a vertical square shape.
- Curtain: Ledge waterfalls which descend over a height larger than the width of falling water stream.
- Plunge: Fast moving water descends vertically, losing complete contact with the bedrock surface. The contact is typically lost due to horizontal thrust of the water before it falls. It always starts from a narrow stream.
- Punchbowl: Water descends in a constricted form and then spreads out in a wider pool.
- Horsetail: Descending water maintains good contact with bedrock most of the time.
- Slide: Water glides down maintaining continuous contact.
- Ribbon: Water descends over a long narrow strip.
- Chute: A large quantity of water forced through a narrow, vertical passage.
- Fan: Water spreads horizontally as it descends while remaining in contact with bedrock.
- Cascade: Water descends a series of rock steps.
- Tiered/Multi-step/Staircase: A series of waterfalls one after another of roughly the same size each with its own sunken plunge pool.
- Cataract: A large, powerful waterfall.
- Segmented: Distinctly separate flows of water form as it descends.
- Catadupa: A cataract or waterfall, originally those of the Nile. The term catadupae refers to people inhabiting near such cataracts; there are suppositions that these people are deaf due to the constant din.
- Tide Fall: A waterfall that directly empties into the sea or ocean.
- Frozen: Any waterfall which has some element of ice.