People walk by a screen showing the news reporting about an earthquake near North Korea&#039;s nuclear facility, in Seoul, South Korea, Wednesday, Jan. 6, 2016. South Korean officials detected an &quot;artificial earthquake&quot; near North Korea&#039;s main nuclear test site Wednesday, a strong indication that nuclear-armed Pyongyang had conducted its fourth atomic test. North Korea said it planned an &quot;important announcement&quot; later Wednesday. The letter read &quot;5.1 Earthquake near North Korea&#039;s nuclear facility.&quot; (AP Photo/Lee Jin-man)