. 0   km . ▁ ▁A ▁magnitude ▁ 6 . 3 ▁after sh ock ▁struck ▁off ▁the ▁sout heast ▁coast ▁of ▁H ok ka ido , ▁Japan ▁on ▁March ▁ 4 ▁at ▁a ▁depth ▁of ▁ 1 2 . 4   km . ▁ ▁A ▁magnitude ▁ 6 . 7 ▁after sh ock ▁struck ▁off ▁the ▁sout heast ▁coast ▁of ▁H ok ka ido , ▁Japan ▁on ▁March ▁ 4 ▁at ▁a ▁depth ▁of ▁ 1 5 . 0   km . ▁ ▁A ▁magnitude ▁ 6 . 4 ▁after sh ock ▁struck ▁off ▁the ▁sout heast ▁coast ▁of ▁H ok ka ido , ▁Japan ▁on ▁March ▁ 5 ▁at ▁a ▁depth ▁of ▁ 1 6 . 0   km . ▁ ▁A ▁magnitude ▁ 6 . 3 ▁after sh ock ▁struck ▁off ▁the ▁sout heast ▁coast ▁of ▁H ok ka ido , ▁Japan ▁on ▁March ▁ 5 ▁at ▁a ▁depth ▁of ▁ 2 5 . 0   km . ▁ ▁A ▁magnitude ▁ 6 . 4 ▁earth qu ake ▁struck ▁the ▁southern ▁G ulf ▁of ▁California ▁on ▁March ▁ 5 ▁at ▁a ▁depth ▁of ▁ 1 0 . 0   km . ▁ ▁A ▁magnitude ▁ 6 . 5 ▁earth qu ake ▁struck ▁off ▁the ▁coast ▁of ▁I sh ik awa ▁Pref ect ure , ▁H ons hu , ▁Japan ▁on ▁March ▁ 7 ▁at ▁a ▁depth ▁of ▁ 1 0 . 0   km . ▁ ▁A ▁magnitude ▁ 6 . 0 ▁after sh ock ▁struck ▁off ▁the ▁sout heast