Wednesday, March 03, 2021

NATURE: 'Peculiar' image captured by NASA satellite remains an unresolved case
Cheryl Santa Maria 



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A NASA satellite has picked up peculiar images featuring mysterious ripples on hills in northern Russia in the Central Siberian Plateau.

On steep hills, the pattern loops tightly, spiraling from top to bottom, fading at lower elevations, and can be seen in several images captured by acquired by the Operational Land Imager (OLI) on Landsat 8 between 2016 and 2020.

© Provided by The Weather NetworkCourtesy: NASA Earth Observatory.

While there are a few possible causes, the case remains unresolved.

Most of the area is covered with different intensities of permafrost, but thawing and freezing cycles have been known to create similar patterns, NASA says. The problem is that these types of patterns normally occur at a smaller scale and face downslope.

Another theory is that persistent freezing and thawing through the seasons are causing layers of soil to mix up and align vertically. Different layers of soil may host different forms of vegetation, allowing for the patterns to be visible from space.

There's also a geological theory. Thomas Crafford of the U.S. Geological Survey called the stripes “layer cake geology,” featuring sedimentary rock layers that have been exposed by erosion. Snowmelt and rain further the erosion and could be contributing to the patterns.

The reason the stripes fade near the bottom, Crafford suggests, is because sediment gathers more uniformly at the river, following millions of years of erosion.

Live Science says the case will remain a mystery until scientists have the opportunity to study the area up close, which could be some time from now.


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