Scientists are evaluating satellite data that reveals, the city of Tehran, is sinking in some places, as much as 10 inches per year. There are also several cities in the United States that are also experiencing this problem. The sinking is called "Subsidence." It is shown through sinkholes and giants cracks. You can read more about it here: Fox Senior Writer, Mendy Weisberger, Live Science article, Tehran Is Sinking Dramatically, And It May Be Too Late To Recover, December 5, 2018.