%A Yasuo Yabe %A Makoto Naoi %A Grzegorz Kwiatek %A Joachim Philipp %A Katrin Plenkers %A Masao Nakatani %A Toshihiro Igarashi %T Aftershock activity of an M2.1 earthquake in a deep South African gold mine observed by a high frequency seismic network %X Objective Overview of our observation Aftershock activity of an M2.1 earthquake. spatial distribution temporal decay Conclusions %C Cape Town, South Africa %D 2009 %L epos192