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Ok, first note - you should not click on this video if you have a problem with rapidly moving images or flashing light. These video artists have taken satellite imagery across the US and combined the frames with extremely rapid shifts so that part of the frame always keeps the same shape but the surroundings flip rapidly from one spot to another. You can see how the geometric designs of civilization stay constant as the landscape shifts from spot to spot.
A mosaic This image, taken from the International Space Station in December, shows the ground near Alliance, Nebraska. The pattern is created by farmland. The area is divided into squares (40 acres I’m going to guess as that was a standard size when lands were being handed out in the U.S. west) and each one has a circle due to central-pivot irrigation systems. Water comes up a pipe in the center and the irrigation system moves in a circle surrounding it to water crops. If you look closely you can see a linear fabric overlaying the circles, most likely showing the path taken by the equipment during the previous harvest. -JBB Image credit https://twitter.com/PC0101/status/421047533498949632/photo/1
Frozen Crop Circles
Our last picture showed circles created by irrigation systems in the state of Nebraska. Here’s that plus ice.
This image was taken by an astronaut on the International Space Station on December 26th, and it shows a portion of the Missouri River in South Dakota. The river cuts a U-shaped meander in this location – streams moving over long distances often meander from side to side, eroding bow-shapes on one side until eventually the river breaks through the center of the bow and resumes its original course. The actual location here is known as Lake Sharpe – it’s on the Missouri river but held behind a dam, creating a man-made lake. This lake has essentially shut down the current in this area and should keep this meander stable for a long time. The dam also allows the lake behind it to freeze at the surface and be covered by snow.
-JBB
Image credit: NASA http://www.nasa.gov/content/frozen-lake-sharpe-south-dakota/
