At a Glance
- This study enhances our understanding of Earth’s geological recycling systems and may reshape how researchers interpret past and future tectonic activity shaping the planet’s surface and inner structure.
- Scientists have discovered that cratons beneath North America are slowly dripping into the mantle, a rare geological process that offers direct insight into the dynamic changes occurring deep underground.
- Cratons are ancient, stable parts of Earth’s crust, typically resistant to change. However, certain geological forces can weaken them, making this real-time observation of their decay particularly significant to geologists.
- Using seismic imaging, researchers found that the Farallon Plate, a sunken tectonic plate beneath North America, redirects mantle flow and destabilizes the craton’s base, causing it to drip downward.
- Although the process poses no surface threat, it provides valuable information about how continents evolve, offering scientists a new lens through which to study the history and mechanics of continental shifts.
Scientists have made a surprising discovery beneath the North American continent: large chunks of the Earth’s crust, known as cratons, are slowly “dripping” away. This process, observed for the first time, occurs deep under the Midwest, where thick rock layers are thinning and sinking into the Earth’s mantle. The study, published in Nature Geoscience, suggests that this unusual phenomenon could be linked to the movement of an ancient tectonic plate below the continent. While this “dripping” does not threaten the surface, it provides important clues about the Earth’s ongoing geological processes.
Cratons are some of the oldest and most stable parts of the Earth’s crust and have been around for billions of years. Usually, these regions remain intact, but certain events can cause them to weaken or lose their layers. For example, in the past, other cratons, like the North China Craton, have lost parts of their deep layers. This discovery is fascinating because it is happening now, allowing scientists to observe the process directly.
The research team, led by Junlin Hua from the University of Texas at Austin, used advanced seismic imaging techniques to map the crust beneath North America. Their study found that the “dripping” is likely caused by the Farallon Plate, a tectonic plate that has been sinking into the mantle beneath North America for millions of years. The Farallon Plate, though far below the Earth’s surface, influences the craton by redirecting mantle flow and weakening the base of the craton, allowing it to drip into the mantle.
While the process is slow and not dangerous to human life, the study is important for understanding how continents form and evolve. “It helps us understand how continents are made, how they break apart, and how materials are recycled within the Earth,” said Thorsten Becker, a co-author of the study. This discovery gives scientists a new way to study the Earth’s inner workings and may provide insights into the future of continental development.
References
- University of Texas at Austin. (2025, April 1). North America is dripping from below, geoscientists discover. Phys.Org; University of Texas at Austin. https://phys.org/news/2025-04-north-america-geoscientists.html
- Hua, J., Grand, S. P., Becker, T. W., Janiszewski, H. A., Liu, C., Trugman, D. T., & Zhu, H. (2025). Seismic full-waveform tomography of active cratonic thinning beneath North America consistent with slab-induced dripping. Nature Geoscience. https://doi.org/10.1038/s41561-025-01671-x
