No sign of a tsunami surge was seen, however, nearly two hours after the earthquake, leading one expert to downplay the threat.
"I would tend to think that if they've seen no evidence of tsunami activity after an hour, then there's probably not going to be much," said Stuart Weinstein, assistant director of the Pacific Tsunami Warning Center
"At this point, it's very unlikely that there will be a Pacific basin-crossing destructive tsunami," Weinstein said.
An official with the Japan Meteorology Agency said while there has been no tsunami wave seen, instruments did measure a 20 centimeter (8 inches) drop in the tidal level, suggesting a surge could be on the way.