From rivers carving through earth to lava melting rock and water slicing through ice, natural channels form intricate, winding paths. While they may appear similar, a new study led by scientists at The University of Texas at Austin has uncovered a key difference: the curves of river channels are distinct from those shaped by lava or ice.
The exact mechanisms behind these differences remain under investigation, but researchers point to the interaction between channel topography and fluid dynamics as a driving factor. In rivers, centrifugal force causes water to flow faster along the outer edges of bends and slower on the inner edges. This leads to erosion on the outer curve and sediment deposition on the inner curve, enhancing the river’s meandering shape.
In contrast, channels formed by lava or ice erode thermally through melting, without depositing sediments. This results in bends that change only along the outer edge, making their curves smaller and less pronounced than those found in rivers.
Understanding these natural processes could provide insights into landscape evolution on Earth and even other planets.
“This distinction sets up a great natural experiment for us to see if the shape, or size, of bends in rivers is distinct from those in volcanic or ice channels,” said Tim Goudge, a co-author on this paper and assistant professor at the Jackson School of Geosciences Department of Earth and Planetary Sciences.
These findings could have the potential to be used as a diagnostic tool for sinuous channels on other worlds, where the fluid’s origin may be unknown and scientists cannot be on the ground to take measurements and samples.
The research was published in Geology.
Juan Vazquez, who earned his undergraduate degree from the Jackson School in 2024, led the research while working with Goudge. He analyzed thousands of bends in rivers and ice channels on Earth and volcanic channels on the Moon. Vazquez said that what he thought was an analysis error at first ended up being an early indication that river bends have a more extreme size than other channels.
“It wasn’t until the parameters for the code we had set for the volcanic channels on the Moon kept failing for the rivers on Earth that we realized, ‘Oh, that’s not a fault of the code. It’s an intrinsically different amplitude,’” Vazquez said.
