North America is ‘Dripping’ into Earth’s Mantle, Scientists Discover

Scientists have discovered that an ancient slab of Earth’s crust beneath the Midwest is pulling North America’s crust downward into the mantle, creating massive “drips.” This process, caused by a remnant of the Farallon plate, leads to **cratonic thinning**, where the continent’s stable crust slowly erodes. Using advanced seismic imaging, researchers mapped this phenomenon for the first time. While it won’t cause immediate surface changes, it provides key insights into Earth’s geological evolution

Scientists have uncovered a fascinating geological process occurring beneath North America. A massive, ancient slab of Earth’s crust, buried deep beneath the Midwest, is pulling the continent’s crust downward into the mantle, creating giant “drips” that extend nearly 400 miles (640 km) below the surface.

This phenomenon spans a vast region from Michigan to Nebraska and Alabama, but its effects appear to influence the entire continent. The process resembles a large funnel, where rocks from across North America are being drawn inward before sinking into the mantle. As a result, parts of North America are gradually losing material from the underside of their crust.

Researchers believe this is caused by a remnant of the *Farallon plate*, a once-massive tectonic plate that subducted beneath the North American plate millions of years ago. Over time, pieces of the Farallon plate broke off and sank into the Earth’s interior. One such remnant, known as the *Farallon slab*, currently sits about 410 miles (660 km) beneath the Midwest and is responsible for a process called *cratonic thinning*—the gradual erosion of ancient, stable parts of the continent’s crust.

For the first time, scientists have observed cratonic thinning in action, thanks to a high-resolution seismic imaging technique called *full-waveform inversion*. This technique allowed researchers to map underground structures with unprecedented detail, revealing how the Farallon slab is actively pulling material downward.

Computer simulations further confirmed that the dripping effect occurs only when the Farallon slab is present, proving its role in shaping the continent’s geological evolution. While this process won’t cause immediate surface changes, scientists believe it could eventually stop as the slab sinks deeper and its influence diminishes.

This discovery offers crucial insights into Earth’s dynamic interior, helping scientists understand how continents form, break apart, and recycle over geological time scales.

(source : live science)

Disclaimer
This article summarizes recent geological research on North America’s mantle dynamics. The findings are based on seismic imaging and computer simulations. While the process of cratonic thinning is ongoing, it does not pose any immediate risks to the surface.