More than half of the U.S. coal mines that were operating in 2008 have closed between that year and 2017, the country's Energy Information Administration (EIA) said in a statement on Wednesday.

The EIA said the number of active coal mines decreased from 1,435 in 2008 to 671 in 2017 -- a decline of 53 percent.

Underground mines in the U.S. saw the largest percentage of closures between 2008 and 2017 at 60 percent. The number of underground mines in production declined by 340, while the number of surface mines in production fell by 410, the EIA said.

Surface mines had a 49 percent closure rate between these dates, but saw a larger decline in production.

While coal production in surface mines decreased 39 percent between 2008 and 2017, underground mines saw a production decline of 24 percent.

Due to a fall in coal demand in the U.S., coal production has declined by more than one-third since 2008 when output peaked.

"The uptick in mine closures since 2008 has largely been driven by economics, and smaller, less profitable mines have been more susceptible to closures," the statement said.

"As the U.S. market contracted, smaller, less efficient mines were the first to close, and most of the mine closures were in the Appalachian region," the statement said.

The Appalachian Basin, located in the states of Ohio and Kentucky, and the Illinois Basin that include the states of Illinois and Indiana, has the most mines in the U.S. More than 77 percent of production in the eastern part of the U.S. comes from underground mines, according to the EIA.

On the other hand, in the western part of the U.S. in the Powder River Basin, located in Montana and Wyoming, there are fewer mines and production mainly comes from a smaller number of large surface mines, the administration noted.

By Ovunc Kutlu

Anadolu Agency

energy@aa.com.tr