Another Canyon in Arizona

ENVIRONMENT

A not-so-grand canyon has opened in the Arizona desert. How? Why? (Forbes)

Learn more about the forces that create earth fissures with our activity.

Teachers, scroll down for a quick list of key resources in our Teachers Toolkit.

Discussion Ideas

 

This basic diagram of an artesian aquifer shows how groundwater can be stored in porous sandstone. Illustration from the archives of Pearson Scott Foresman, donated to the Wikimedia Foundation. Public domain

This basic diagram of an artesian well shows how groundwater can be stored in porous sandstone.
Illustration from the archives of Pearson Scott Foresman, donated to the Wikimedia Foundation. Public domain

  • The big earth fissure in Pinal County is a result of aquifer drawdown or aquifer depletion. What is aquifer depletion?
    • Just what it sounds like. Aquifer depletion describes the process by which people pump more water out of aquifers than can be replaced by rain or snow.
    • In Pinal County, aquifer depletion empties the porous sandstone aquifer whose pockets hold the local groundwater. Aquifer depletion means that eventually, the brittle sandstone collapses at its weakest points, causing land subsidence, sinkholes, and earth fissures.

 

The feathery aquifers of Pinal County, Arizona, are part of the huge Basin and Range aquifers that stretch across the Great Basin from Idaho and Oregon and through Nevada and southeastern California. Map by the USGS

The feathery aquifers of Pinal County, Arizona, are part of the huge Basin and Range aquifers that stretch across the Great Basin from Idaho and Oregon and through Nevada and southeastern California.
Map by the USGS

 

  • What are some reasons the aquifers in Pinal County might be depleted? How does your community use groundwater?
    • Communities use water for many, many purposes.
      • drinking
      • hygiene
      • recreation, such as swimming pools and artificial lakes
      • maintenance of gardens and lawns
      • agriculture
      • industry or manufacturing

 

  • Can land lost to subsidence and earth fissures be reclaimed?
    • No. Once the soil and sedimentary rock collapse on themselves, land generally remains subsided.

 

 

 

 

TEACHERS TOOLKIT

Forbes: An Enormous Crack Just Opened Up In The Middle Of The Arizona Desert

Nat Geo: Groundwater Movement activity

Arizona Department of Water Resources: Land Subsidence in Arizona

Owlcation: Geologic Hazards: What You Need to Know About Earth Fissures

3 responses to “Another Canyon in Arizona

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