( CNN ) -- Scientists are studying what caused tsunami-like waves that observers spotted near the New Jersey coast earlier this month . `` The source is complex and still under review , '' the National Weather Service 's West Coast/Alaska Tsunami Warning Center says on its website . In New Jersey 's Barnegat Inlet , a fisherman said he saw a massive , 6-foot-tall wave surging toward the coast on June 13 . Tsunami-like waves were observed at more than 30 tide gauges in areas along the East Coast , the center said . Meteorological factors and the slumping of the continental shelf east of New Jersey may have played a role , the center said .
Fisherman describes a 6-foot wave near the New Jersey coast . Tidal sensors also detect tsunami - like waves . Scientists are studying what caused the waves , the National Weather Service says .