露ろ天てん掘ぼり

noun

surface mining; open-pit mining; open-cut mining

Mining method where minerals are extracted from an open pit or surface excavation, as opposed to underground mining (坑内掘り).

See also: 坑内掘り

• この地ち域いきでは、石せき炭たんを露ろ天てん掘ぼりで採さい掘くつしている。

  In this region, coal is mined by open-pit mining.

• 露ろ天てん掘ぼりは坑こう内ない掘ぼりよりコストが低ひくい場ば合あいが多おおい。

  Surface mining is often less costly than underground mining.