How did the Andes Mountains get so huge? A new geological research method may hold the answer

Researchers at the University of Copenhagen have developed a new method that allows for the estimation of how Earth's tectonic plates changed speed over millions of years. Using this method, they have investigated the formation of the Andes, the world's longest above-water mountain range, and proposed a new hypothesis.

Tectonic plates are large pieces that make up Earth's surface and constantly move, albeit at a slow rate. The researchers focused on the tectonic plate on which the Andes sits and found that it experienced two significant slowdowns over the past 15 million years. These slowdowns coincided with periods of compression and rapid growth of the Andean range.

The study suggests that the preexisting portion of the Andean range may have acted as a brake on the movement of the Nazca Plate, which is located to the west and collided with the mountains, causing them to grow taller. As the plates slowed down, the mountains widened instead of growing taller.

The findings provide new insights into the formation of the Andes and the forces at play in shaping Earth's mountain ranges. The research has been published in the journal Earth and Planetary Science Letters.