In other EarthDates, we’ve talked about how water can shape Earth’s surface.

It erodes mountains, slowly leveling them over millions of years.

It fills aquifers, and when those are drained too much or too rapidly, the surface of the land above them can sink.

But another way water can shape the land is simply by weighting it down. And when billions of tons of water evaporate from a mountain range or inundate a city, the land can rise or fall.

California suffered a severe drought from 2011 to 2015. Scientists studying its effect on the landscape surveyed the Sierra Nevada range using sophisticated GPS.

This technology can detect changes in elevation of just 1 mm. It revealed that the mountain range, which had lost 10 cubic miles of water to evaporation, rose 1 inch during the drought.

Conversely, researchers studying the effects of Hurricane Harvey found that it dumped 20 cubic miles of water on Texas and Louisiana that weighed more than 100 billion tons.

This caused the Earth to sag beneath its weight, up to an inch depending on the amount of floodwater.

They found that they could even trace the path of the storm over the land by following the surface depressions left behind it.

As Harvey’s floodwater drained into the Gulf of Mexico, GPS measurements showed the surface slowly rebounding to pre-flood levels.