Q:

How are potholes formed in rivers?

A:

Potholes form at the bottom of rivers as eddies gouge out the bedrock of the river bottom. These eddies form as isolated whirlpools break off from the main current of the river. If the whirlpool pattern is persistent, it can dig permanent irregularities in the rock that form the initial conditions for further erosion of the pothole.

Once the small depression is present in the river bedrock, flowing water transports sand and small rocks into it. The whirling water of the eddy carries the abrasive material around the interior surface of the depression. This action scrapes the walls and bottom of the enlarging pothole and works to enlarge the feature. As the pothole grows, larger stones are carried into it and accelerate the erosion of the feature's sides. These large stones, which are called abraders, can be carried out by the same spiraling water that carries them in, or they can settle to the bottom of the pothole where they remain indefinitely.

The pothole is usually exposed as the river above it shifts its course. The water inside then drains off or evaporates away, leaving a rubble-strewn pit that can be as much as 25 feet wide and 80 feet deep.

Sources:

  1. people.uwec.edu

Is this answer helpful?

Similar Questions

  • Q:

    Why are rivers important?

    A:

    Rivers are important because they transport water, provide habitat, support economic activities and enable transportation. Rivers provide life-sustaining supplies of water and important nutrients for living organisms around the world, including humans, plants and fish. Large rivers provide power for hydroelectricity and facilitate the movement of people and goods within nations and across borders.

    Full Answer >
    Filed Under:
  • Q:

    How are bays formed?

    A:

    According to NationalGeographic.com, bays are formed through various ways, such as plate tectonics, overflowing of the ocean to a coastline and the slicing of a glacier through a bedrock. Bays are bodies of water partially surrounded by land, and they are typically less enclosed and smaller than a gulf.

    Full Answer >
    Filed Under:
  • Q:

    What are rivers used for?

    A:

    Rivers are used for transportation, irrigation, generating energy and performing work, such as turning waterwheels. Rivers are also vital sources of fresh water for both industrial and residential applications.

    Full Answer >
    Filed Under:
  • Q:

    How do rivers form?

    A:

    Rivers form when flowing water from precipitation or springs flows over land and accumulates in existing low points in the topography, eroding it and forming a riverbed. Rivers are channels for moving water, which always seeks to flow downhill, and indeed, many rivers start from small channels in mountains. As it erodes the landscape, different aspects of the interaction between flowing water and the ground cause winding and branching.

    Full Answer >
    Filed Under:

Explore