AlHijjah 04, 1436, September 18, 2015, SPA -- The powerful earthquake off Chile also sparked a tsunami advisory for Hawaii and parts of coastal California, prompting officials in both U.S. states to urge caution around shorelines. The Pacific Tsunami Warning Center in Hawaii first issued a more serious tsunami watch for the Pacific island chain shortly after Wednesday's magnitude-8.3 earthquake. Officials later downgraded that to an advisory, saying that no major tsunami was expected in the state. But they warned that sea-level changes and dangerous currents could threaten those in or near the water. The warning center estimated that the effects from the tsunami, with waves possibly reaching 1 meter above tide level, would arrive early Thursday. The Honolulu Department of Emergency Management said people should stay out of the ocean early Thursday, and the U.S. Coast Guard urged caution. A similar advisory was issued for southern and central California, affecting about 480 kilometers of coastline from the southern end of Orange County, south of Los Angeles, to most of San Luis Obispo County on the central coast.