The existence of waterfalls that formed without any external influence could change the current understanding of the planet's geology, researchers have stated.
A team of scientists discovered a new way in which a waterfall can form. During an experiment, they concluded that the river's turbulence alone is enough to carve its own channel and form a waterfall.
The findings, which were published
in the journal Nature
, contradict the previous belief that waterfalls can only form if there is an external trigger acting on a river. Scientists have always looked at waterfalls as windows to the past
, revealing a history of tectonic activity
or changes in the sea level
"There's this idea that we can look at the topography of a planetary body and use it as a record of its history," stated
Joel Scheingross, an assistant professor at the University of Nevada, Reno and the author of the study.
The researchers simulated a river in a lab using a 24-foot long and 1-foot wide polyurethane foam to simulate a bedrock. They tilted it to about a 10-degree incline and poured water mixed with gravel to mimic sediment.
A few minutes into the experiment, the water started to carve a channel through the foam. After 2.4 hours, a staircase of pools started to form. By the third hour, a small waterfall has appeared.
As more time passed, the researchers observed that continued erosion from the gravel stopped that waterfall behavior and allowed a new waterfall to form. They said that each cascade stuck around for 20 minutes, representing 10 to 10,000 years in real life.
"Instead of having to wait decades or millennia to run these experiments, we can run them on a timescale of a Ph.D. thesis and actually observe changes in the lab," added
Reevaluating The Current Understanding Of Earth's Geology
The scientists cannot say for sure that a similar phenomenon is happening in the real world. The process has only been observed in the lab.
The team clarified that their findings are not meant to discredit previous studies that claim waterfalls were formed due to external forces. It only points out another method that has not been considered before that might add to the understanding of how the surface of the planet changes through time.
The next step is to find waterfalls in the real world where structures similar to the lab-made river exist.