NASHVILLE, Tenn. (WKRN) — A new scientific study shows that some of the largest cities in the United States are slowly sinking.

In fact, Nashville appears to be sinking about one millimeter each year. News 2 spoke with Leonard Ohenhen, one of the researchers in the study, who said the sinking across the country is caused by both natural and human-caused processes.

According to Ohenhen, water use, drilling of natural gas/oil, and the weight of infrastructure is causing sinking in some of the cities in the study. He added that sinking in Music City is caused naturally by a process called "Glacial Isostatic Adjustment."

Glacial Isostatic Adjustment is the land's reaction to the melting of the glaciers thousands of years ago. Ohenhen said this causes some locations to rise and others to sink.

"Think of it like a memory foam, if you put a large weight on it, where the weight is after the weight is removed starts to rising, and places that were adjusting to where the weight was would rise due to that weight, but when the weight is removed it starts going down to sort of have equilibrium," Ohenhen told News 2.

Nashville's sinking could reportedly lead to worse flooding during heavy rain events, but Ohenhen said there shouldn't be many infrastructure issues because the whole city is sinking at the same speed.

"Roads, railways, buildings, and other infrastructure themselves can over time be compromised due to land subsidence, but in Nashville, the good thing is all the land is sinking almost at an even rate," he explained.

Ohenhen said this isn't the same for other cities in the study, adding many of the cities in Texas have a high or very high risk of infrastructure issues.

According to the study, not every city is sinking. In fact, Memphis was one of the cities that were slowly rising. Ohenhen said the entire city isn't rising, but parts of Memphis are rising due to the natural recharge of the groundwater.

The biggest concern with the sinking is coastal flooding, but Ohenhen said obviously that is not a problem for Nashville.

To read the entire study, click here.

News Source : https://www.wkrn.com/news/local-news/nashville/scientists-say-nashville-is-sinking-heres-why/