Ground-penetrating radar imaging of a concealed active fault in the district damaged by the 2011 northern Nagano-ken earthquake, central Japan. 地質学雑誌,119(1):1-2 2013(Jan. 20) Author:宮田隆夫, 大塚 勉 Keywords:ground-penetrating radar, active fault, earthquake, 地中レーダー,活断層,地震