Scientists from the University of Columbia have been the first to demonstrate that “bubbles” of lighter sand can form and rise through heavier sand when subjected to vibrations and gas flow.
Assistant professor of chemical engineering at Columbia Engineering Chris Boyce said the findings could be “transformational” for a number of applications.
“We have found a granular analogue of one of the last major fluid mechanical instabilities,” Boyce said.
“Our findings could not only explain geological formations and processes that underlie mineral deposits but could also be used in powder-processing technologies in the energy, construction, and pharmaceuticals industries.”
The phenomenon is initiated by the channelling of gas upwards through sand deposits, causing clusters of lighter, larger particles to rise past smaller, heavier ones.
The study was published in the Proceedings of the National Academy of Sciences, in collaboration with a group at Swiss University ETH Zurich.
Boyce said the team was equally intrigued about what this discovery means for the geological community.
“We are especially excited about the potential impact of our findings on the geological sciences—these instabilities can help us understand how structures have formed over the long history of the Earth and predict how others may form in the future,” Boyce said.