(CNN) -- Japanese authorities on Monday called off a tsunami advisory after a 6.5-magnitude earthquake off the country's northeast coast produced little more than ripples.
However, the Japan Meteorological Agency urged coastal residents to remain prepared to evacuate because of a continued threat of aftershocks that could spawn tsunamis.
Authorities issued a tsunami advisory Monday morning for coastal areas of Miyagi Prefecture in northeastern Japan after a quake struck the region at 7:24 a.m. The tsunami advisory was cancelled at 9:05 a.m.
The tsunami height had been expected to climb to half a meter, or 1.6 feet, tall. Video of the coastal area in the tsunami zone aired by Japanese broadcaster NHK showed slight ripples to the water, which "could be indicative of rises" in water levels, CNN meteorologist Jacqui Jeras said.
Hirofumi Yokoyama, a meteorological official, said Monday's temblor was the latest of a series of aftershocks to rattle the region since a 9.0-magnitude earthquake and the tsunami it triggered devastated coastal villages, killed thousands of people and set off Japan's worst nuclear disaster since World War II.
"We have to be ready for jolts with the intensity of 6 or so, and so people have to be on the alert," Yokoyama told reporters.
Yokoyama said aftershocks of this magnitude could still produce dangerous tsunamis.
The Monday morning quake struck about 70 miles east of Sendai at a depth of 3.7 miles, according to the U.S. Geological Survey, not far from where the March 11 quake hit.