Rick Just
  • Home
  • Blog
  • Author
  • Speaker
  • Contact

Idaho Hot Spot (tap to read)

1/22/2023

Comments

 
What do you think of when you hear the term “Idaho hot spot?” Maybe a new restaurant or trendy bar? Not nearly as hot as the subject of today’s post.
 
If you look at a topographic map of Idaho you can’t help but notice the swoop of the Snake River as it moves east to west through the southern part of the state. That’s called the Snake River Plain. It would be natural to assume that the Snake River created it, perhaps as it meandered back and forth through geologic time. That assumption would be wrong. The Snake River Plain was created by a lot of geological forces, including water erosion, but it’s primarily a signature left behind by a hot spot beneath the earth’s crust.
 
The crust of the earth is moving west in relation to this hot spot, so its impact is moving east. Think of the hot spot as being stationary while the crust moves west. In the illustration you can see where the hot spot was 16 million years ago along the Oregon/Nevada border. As the crust continued west, the stationary hot spot effectively move east. It “entered” the state some 15 million years ago, was somewhere around Bruneau Dunes about 12 million years ago, and was parked under Craters of the Moon National Monument about 7 to 10 million years ago.
 
As the hot spot moved, it produced a lot of volcanic activity on the surface. The Craters area is one visible indication of this. The area known as Island Park is where the hot spot made a big showing about 5 million years ago. It left behind a couple of calderas, or collapsed volcanoes. The Henry’s Fork Caldera is between 18 and 23 miles across. That’s huge. Still, it comfortably fits INSIDE the Island Park Caldera, which is 50 to 65 miles wide. Upper Mesa Falls is where the water of the Henrys Fork splashes over the edge of the old volcano.
 
So, has the hot spot gone away? Nope. You can find it today under Yellowstone National Park heating up the geysers and hot pools and causing social media to come unglued whenever there is swarm of earthquakes.
 
By the way, this is the same thing that’s going on with the Hawaiian Islands. That hot spot acts of as the earth’s crust moves over the top of it, too. Since there is no land mass the resulting volcanic activity produces islands. One of the oldest islands, Kauai, is to the furthest west. As that hot spot moved—in relation to the crust—east, it created Oahu, Maui, and then the Big Island, Hawaii. That’s where the volcanic activity is today.
 

Picture
Past locations of the hot spot in millions of years. The illustration is courtesy of Kelvin Case at English Wikipedia.
Speaking of Idaho history posts are copyright © 2020 by Rick Just. Sharing is encouraged. If you don’t find a button that lets you do that, find the post on Speaking of Idaho. If you’re missing my daily posts, select the RSS button, or select See it First under the Facebook Following tab.
Comments
    Like and follow Speaking of Idaho on Facebook and Twitter.

    Subscribe to the Speaking of Idaho newsletter

    * indicates required
    Email Format
    Picture
    The first book in the Speaking of Idaho series is out. Ask for it at your local Idaho bookstore, find it on Amazon, or, if you want a signed copy, click the button.
    Picture
    Rick's book about Fearless Farris is available on Amazon! Click the picture above to be taken to Amazon. If you'd like an autographed copy, click the button below.

    Author, Speaker

    Rick Just has been writing about Idaho history since 1989 when he wrote and recorded scripts for the Idaho Centennial Commission’s daily radio program, Idaho Snapshots. His latest book on Idaho history is Images of America, Idaho State Parks. Rick also writes a regular column for the Idaho Press.

    Rick does public presentations on Idaho's state park history and the history of the Morrisite war for the Idaho Humanities Council's Speakers Bureau.
    ​


    Check out Rick's history of Idaho State Parks.

    The audio link below is to Rick's Story Story Night set called "Someplace Not Firth"

    RSS Feed

Speaking of Idaho history posts are copyright © 2023 by Rick Just. Sharing is encouraged. If you’re missing my daily posts, select the RSS button, or select See it First under the Facebook Following tab.

*As an Amazon Associate I earn from qualifying purchases. That means if you follow a link (generally to a book) from my page to an Amazon page, I get a tiny percentage of any purchase you may make.