Scientists from the University of Southern California found out that the Atlas Mountains stand on a layer of hot molten rock, defying the previously believed theory that mountain ranges sit on a deeper, larger land formation beneath them.

The molten rock on which the mountain range stands is predicted to flow as far as the Canary Islands of northwestern Africa.

According to previous theories, the Earth’s crust should be supported by a sufficient measure of depth for it to be able to stand sturdy and stable. This is similar to the concept of istostacy on icebergs, postulating that a massive iceberg is likely to stand on a larger mass of ice. However, the new findings of this study showed that the theory is not true for the Earth’s entire surface.

Assistant Professor of Earth Sciences at the USC Dornsife College of Letter, Arts, and Science, and co-author Thorsten Becker of the USC utilized seismometers to get the measurement for the lithosphere’s thickness. The lithosphere is the outermost layer of the earth’s crust. The team was able to gather 67 distant seismic events from over 15 seismometer and they use these readings to visualize into the Earth’s subsurface.

The researchers found that the crust beneath the Atlas Mountains has a depth of only 35 km, which is 15-km shorter than the traditional model used on mountain formation studies.

"Our findings confirm that mountain structures and their formation are far more complex than previously believed," Miller said in a press release. "This study shows that deformation can be observed through the entire lithosphere and contributes to mountain building even far away from plate boundaries.”

The Atlas Mountains is a 2,500-km mountain range across the northwestern Africa and stretches through through Algeria, Morocco and Tunisia. It separates the Mediterranean and Atlantic coasts from the Sahara Desert.

This study was published in the January 1 issue of Geology and was also featured on Nature Geoscience.