WASHINGTON: A magnitude 5.9 earthquake struck off the coast of Oregon on Wednesday and was followed a minute later by a smaller quake off the coast of central California, the US Geological Survey said.The Pacific Tsunami Warning Center said the quakes were unlikely to trigger a tsunami.The Oregon quake was initially reported as a magnitude 6.2 and the California one as a 5.3.Both were later downgraded.It was not immediately know whether the quakes caused any damage or casualties. (Reuters)