The Earth's Crust Is Going through Massive Changes Under California at an Alarming Rate

The crust of Earth constantly changes due to natural and environmental factors. As a result, continents have shaped up over centuries. In a recent study, experts have discovered how the land we live on has been undergoing a massive geological change. The research was published in a 2024 edition of Advancing Earth and Space Sciences and it detailed how the crust of our planet is slowly chipping away and sinking into the mantle.

The phenomenon is currently occurring beneath the Sierra Nevada mountains of California. Experts suspect the geological change has been ongoing for millions of years without our notice. This discovery could lead researchers to figure out finer details about the formation of continents. The research on the site mentioned that the process of erosion underneath the mountains is called differentiation. It happens when the dense layers of the Earth's crust start to sink and get absorbed by the mantle, leaving behind only lighter layers of the crust.

"Our observations provide progressive snapshots of a lithospheric foundering process spanning several million years and hundreds of kilometers, illuminating a fundamental differentiation process by which continents are built," the researchers noted in the paper. Experts used seismic data from over four decades to map the northern, central, and southern regions of Sierra Nevada, along with the eastern border of California. Geologists have uncovered signs of a critical separation between the cool continental crust and mantle below, according to Science Alert.

"Our results support a hypothesis that lithospheric removal is progressive along the orogen," the study detailed. "While some studies infer that foundering occurred under the southern Sierra and then stalled. Recent seismicity observations and our results suggest that it is presently active under the central Sierra. It may continue to propagate to the northern Sierra in the future. This progression, spanning several millions of years and hundreds of kilometers along an orogen, may be typical for continental crust differentiation on Earth." 

The presence of relatively higher proportions of minerals that include silicates, aluminum, and potassium, the crust we live upon, typically rises a bit higher than the submerged chunks of oceanic crust, which tend to be saturated with heavier elements like iron and magnesium. "You could be standing in the Sierras fishing, and there could be this huge layer peeling off beneath you and you don’t even know," Vera Schulte Pelkum, a geoscientist at the University of Colorado Boulder, said, stated Live Science. 

"Previous research hinted that this peeling might have happened below the southern Sierra 3 million or 4 million years ago," Pelkum mentioned to the outlet. "Now, we're saying, 'I think it's still going on,'" and she said, "So we're kind of catching it in the act." Pelkum theorized that the same "continental-crust building process" could be happening at other places in the world other than California. Some of that locations of interest are New Zealand, the Anatolian plateau in Turkey, and the Carpathian Mountains in Eastern Europe. "We could go and look for this in several other places where people have proposed that maybe the lithosphere used to be thicker and has peeled off now," she concluded.