A storm that blew through earlier this month might have spurred a rare phenomenon for the East Coast: a tsunami.
The National Oceanic and Atmospheric Administration's West Coast/Alaska Tsunami Warning Center said it happened during the afternoon of June 13 in close conjunction with a weather system known as a low-end derecho. The tsunami was detected by more than 30 tide gauges.
The highest peak amplitude was recorded in Newport, R.I, where it reached just under a foot above sea level.
Brian Coen told observers he was spear fishing near the mouth of Barnegat Inlet, N.J., when he spotted a strong outgoing tide expose rocks before he saw a wave 6-feet high span the inlet.
Two of three people who were swept off the rocks of the jetty by the wave required medical attention.
Mike Angove, head of NOAA's tsunami program, said scientists are still trying to determine what caused it, but that it behaved like a tsunami rather than storm surge.
He said it could have been a rare meteotsunami, which is a tsunami caused by weather, or it could have been caused by a landslide off the continental shelf, which is less rare but still uncommon.
Scientists said it's also possible the slumping at the Continental Shelf east of New Jersey played a role.