( CNN ) -- A tsunami advisory announced shortly after a 7.0-magnitude earthquake struck Japan 's Ryukyu Islands early Saturday has been canceled , Japan 's Meteorological Agency reported . There was no tsunami damage `` though there may be slight sea level changes from now on , '' it said , referring to the areas affected by the advisory -- the Okinawa Islands , the Amami Islands and the Tokara Islands . The quake was centered 10 kilometers ( 6.2 miles ) deep and struck at 5:31 a.m. ( 3:31 p.m . ET Friday ) about 85 kilometers ( 53 miles ) from Okinawa . The quake was felt on Okinawa , with shaking that lasted about 15 seconds , said Lt. Col. Daniel King of the U.S. Pacific Command . He told CNN that commanders in Japan and Hawaii were trying to get damage and casualty reports from U.S. military stations on Okinawa , but had heard nothing in the immediate aftermath . About 20,000 U.S. troops -- mostly Marines , along with Navy and Air Force personnel -- are stationed on eight bases on Okinawa , he said . Are you there ? Send photos , video . iReporter Kristina Donaldson , who lives in central Okinawa , said the quake `` seemed to last longer than other ones we have experienced here . '' `` We felt the quake pretty good this morning , '' she said , but life there was largely unaffected . `` I just walked down to the coastline and the kids are walking to school as they always do . No sirens , or any destruction from where we are . '' Okinawa resident Eric Shepherd said his grandmother-in-law described it as the strongest quake she had felt in her 90 years on the island . `` It felt like some really bad airplane turbulence , '' Shepherd said , adding that one of his two children slept through what seemed like a minute-long `` rumble . '' `` I had no problem walking to the kids ' room to check on them '' during the quake , he said . CNN 's Mike Mount contributed to this report .
NEW : Japan 's Meteorological Agency cancels tsunami advisory . NEW : `` There may be slight sea level changes from now on , '' agency says . Quake centered about 6 miles deep , 53 miles east of Okinawa .