How Waterfalls Are Formed
Questions and Answers
- 1.
Waterfalls are usually found in the lower course of a river.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
Waterfalls are usually found in the upper course of the river where the water travels much more quickly.Rate this question:
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- 2.
The main reason a waterfall forms is because
- A.
It rains a lot and therefore the water has a lot of velocity.
- B.
The water cascades over a layer of hard rock and erodes a layer of soft rock underneath.
- C.
The river is finding the easiest route to sea eroding through the soft rock.
- D.
Erosion is greatest on the outside of the meander bend.
Correct Answer
B. The water cascades over a layer of hard rock and erodes a layer of soft rock underneath.Explanation
A waterfall forms because the water cascades over a layer of hard rock and erodes a layer of soft rock underneath. This erosion process occurs over time as the force of the water flowing over the hard rock gradually wears away the softer rock beneath it. This creates a drop in elevation, resulting in the formation of a waterfall. The continuous erosion of the soft rock underneath the hard rock layer allows the waterfall to persist and maintain its shape.Rate this question:
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- 3.
Which word means 'the slow wearing away of something'?
- A.
Erosion
- B.
Collapse
- C.
Gorge
- D.
Retreat
Correct Answer
A. ErosionExplanation
Erosion refers to the gradual process of wearing away or breaking down of something, such as soil, rock, or land, usually caused by natural elements like wind, water, or ice. It involves the removal and displacement of material over time, leading to changes in the landscape or the gradual destruction of structures.Rate this question:
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- 4.
Which word means 'a narrow valley with steep walls, usually with a river or stream at the bottom'?
- A.
Meander
- B.
Ox-bow lake
- C.
Gorge
- D.
Delta
Correct Answer
C. GorgeExplanation
A gorge is a word that means 'a narrow valley with steep walls, usually with a river or stream at the bottom'. It is a geographical formation characterized by its deep, narrow shape and steep sides. This term is commonly used to describe a landscape feature where a river has cut through rock, creating a deep and narrow valley. The word 'meander' refers to a winding or curving path, 'ox-bow lake' is a term for a U-shaped body of water formed when a meandering river is cut off, and 'delta' describes a landform at the mouth of a river where sediment is deposited.Rate this question:
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- 5.
As the soft rock continues to erode, what is formed at the foot of a waterfall?
- A.
Meander
- B.
Delta
- C.
Plunge pool
- D.
Estuary
Correct Answer
C. Plunge poolExplanation
A plunge pool is formed at the foot of a waterfall as the soft rock continues to erode. The force of the falling water creates a deep pool by eroding the rock and carrying away the debris. Over time, the constant impact of the falling water causes the pool to deepen and widen. Plunge pools are often characterized by their circular or bowl-like shape and can be found at the base of many waterfalls. They provide a unique habitat for aquatic plants and animals and are often popular swimming spots.Rate this question:
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- 6.
Eventually the ______ _______ at the top of the waterfall loses all of its support and falls into the plunge pool.
Correct Answer
hard rockExplanation
The phrase "hard rock" refers to a type of solid and durable material that is resistant to erosion or weathering. In the context of the question, the "hard rock" at the top of the waterfall is subjected to the constant force of water flow, causing erosion over time. As the erosion progresses, the support for the hard rock diminishes until it eventually collapses and falls into the plunge pool below.Rate this question:
- 7.
As this process continues, the waterfall moves further and further back up the river towards it's source. This process is called a ___________.
Correct Answer
retreatExplanation
The given correct answer for this question is "retreat". The explanation for this answer is that as the process continues, the waterfall moves further back up the river towards its source. This implies that the waterfall is retreating or moving in a backward direction.Rate this question:
- 8.
As the waterfall moves back up towards the source of the river a _______ is formed.
Correct Answer
gorgeExplanation
As the waterfall moves back up towards the source of the river, a gorge is formed. A gorge is a narrow and steep-sided valley that is typically formed by the erosive action of a river or glacier. In the case of a waterfall, the constant flow of water over time can erode the rock and create a deep, narrow gorge as the water moves upstream. This process is often seen in areas where the river has cut through layers of resistant rock, leaving behind a dramatic and picturesque landscape.Rate this question:
- 9.
Which word means' to move backwards or withdraw'?
- A.
React
- B.
Retreat
- C.
Reveal
- D.
Respond
Correct Answer
B. RetreatExplanation
Retreat means to move backwards or withdraw. It is the correct answer because it accurately matches the definition given in the question. The other options, react, reveal, and respond, do not have the same meaning as retreat.Rate this question:
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- 10.
A process of __________ causes the layer of soft rock to gradually wear away.
Correct Answer
erosionExplanation
Erosion is the process by which the layer of soft rock gradually wears away. It involves the movement of soil, rocks, and sediments through the action of wind, water, or ice. Over time, these agents of erosion can break down and carry away the soft rock, resulting in the gradual wearing away of the layer.Rate this question:
- 11.
As more and more of the soft rock erodes, a _______ _______ is formed at the base of the waterfall.
Correct Answer
plunge poolExplanation
As more and more soft rock erodes, the force of the waterfall creates a deep and circular depression at its base. This depression is known as a plunge pool. The continuous erosion of the soft rock by the falling water causes the pool to deepen and widen over time. The plunge pool acts as a natural reservoir for the water, absorbing its energy and preventing further erosion downstream.Rate this question:
- 12.
A waterfall will form where you find
- A.
Rapids
- B.
Hard and soft rock
- C.
A gorge
- D.
A meander
Correct Answer
B. Hard and soft rockExplanation
A waterfall will form where you find hard and soft rock because the softer rock erodes more easily than the harder rock. As the water flows over the rapids, it erodes the softer rock faster, creating a drop in elevation. Over time, this erosion deepens the channel and forms a gorge. The harder rock resists erosion and creates a step-like formation, resulting in the waterfall. Therefore, the presence of both hard and soft rock is necessary for the formation of a waterfall.Rate this question:
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Mar 21, 2023Quiz Edited by
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Feb 01, 2015Quiz Created by
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