It was 10:36 a.m. on October 9, 2006, when South Korea's sensors first picked up the abnormal seismic waves.Around half an hour later, experts started narrowing down the location of the epicenter. Eventually, they concluded it was Gilju County, an area in North Korea's northernmost province.What Seoul's equipment was detecting was North Korea's first-ever nuclear test, carried out at its only known test site in the North Hamgyong region.Read More on WorldIt would end up being the first of six, spanning over a decade, that have punctuated Pyongyang's journey to weaponizing nuclear material and insisting it will be recognized as…