Team led by Teng Wang, from the University of Beijing, used satellite radar measurements of soil deformation in the Aral Sea Basin between 2016 and 2020
The drought that occurs in the sea of Aral, which lost 93% of its volume, caused the earth’s mantle under the old bed to rise seven millimeters per year.
Human activity affects the processes under the earth’s crust for decades and the drought of what was once the fourth largest saline lake in the world caused the rocky cloak to rise and flow as a viscous liquid, according to a study published in the journal Nature Geoscience, led by Chinese researchers.
Located in Central Asia, the Aral Sea, which bathes Kazakhstan and Pakistan, began a process of drying in the 1950s, when the feeding rivers began to be over-exploited for irrigation.
As a result, between 1960 and 2018, the lake surface was reduced by 90% and its volume by 93%, leaving in its place a large salt -rich desert.
The weight of the lake water before shrinking was large enough to cause the earth’s crust sinking under it, so scientists expected to occur some surface elevation as the lake dried.
The team led by Teng Wang of the University of Beijing used satellite radar measurements of soil deformation in the Aral Sea Basin between 2016 and 2020.
They found that the old lake bed continued to rise at an average rate of about 7 millimeters per year and that the elevation was observed in a vast area up to 500 kilometers beyond the original center of the lake.
“This elevation enhances the potential of human activities to influence the deep dynamics of the earth and the interconnection of surface and cloak processes,” the study says.
The authors used simulations to show that the characteristics of this observed elevation are best explained by rocks of the cooler higher than a depth of about 150 kilometers that behave like an extremely viscous fluid.
This rock was previously shifted by the weight of water in the lake, but the authors now estimate that the rock is returning to its previous location to a pace comparable to the tectonic movement of the plates, and will continue to do so for many decades.
