Many people don’t believe that sand will be in short supply, and in fact, gravel is the most extracted substance on earth, surpassing fossil fuels. On June 11th a new study published in Nature by the University of Sydney in Australia showed that we were wrong in calculating sand.
Associate Professor Ana Vila-Concejo, of the University of Sydney’s School of Geosciences, said: “Not all sand shapes are the same, but current models that measure sand and its movements are measured on the basis that sand is circular, which means that the results are not accurate, especially in coastal areas that are vulnerable to climate change. “
In general, sand formed by silica and quartz rock is round. Carbonate rock sands from shell, coral and marine animal bones are often oval, with smaller densities and irregular shapes.
To do this, the researchers developed a new engineering model that can measure sand of different shapes and densities. Data on carbonate sands collected near the Great Barrier Reef over six years were then measured.
It was found that the previous model underestimated the surface area of carbonate sand by 35%, overestimated 20% of the translation speed of the carbonate sands under the sea, and underestimated its height by 10%.
The researchers say the new model is a better way to assess the impact of beaches and atolls in carbonate-rich areas on marine hydrodynamics, especially in coastal areas vulnerable to climate change. This means that we can more accurately map how ocean changes will affect marine ecosystems, dominated by carbonate sands.
Previous studies have shown that while deserts account for 20 percent of the Earth’s surface, the sand in the desert is too smooth to use. The vast majority of angular sand suitable for industrial use comes from rivers, which account for less than 1% of the Earth’s area.
About 32 billion to 50 billion tons of sand are used worldwide each year, mainly for cement, glass and electronics, but this is higher than natural regeneration. Thus, by the middle of this century, demand may exceed supply.