On June 13th, 2013 around 4 pm, a tsunami-like event hit Wickford Harbor, Rhode Island.  The change in current was dramatic, accelerating from the normal 1-2 knots up to 6-7 knots out of the harbor, causing small property damage.

Local boat owners contacted the Graduate School of Oceanography, seeking an explanation for this unusual event. In response, a group of URI faculty, marine research scientists, and graduates students met with local yachtsmen, NOAA officials, and others at the URI Bay campus to determine what happened, and why it happened.

NOAA tide gauges showed a tsunami-like event occurring as far north as Maine and as far south as North Carolina.  A seismic source, a frequent cause of tsunamis in the Pacific Ocean, was ruled out, as there were no detectable earthquakes in the Atlantic during this time.

The URI team – Christina King, Richard Yablonsky, Yang Shen, John Merrill, Christopher Kincaid and Robert Pockalny – examined other possibilities. Meteorological experts brought attention to the possibility of a meteotsunami – a tsunami caused by an atmospheric disturbance.  Thunderstorms that passed offshore earlier in the day on June 13th created a pressure wave over the ocean. The pressure disturbance caused a tsunami-like wave along the coast. Pressure, wind speed and temperature measurements from NOAA’s stations along the East Coast suggest the pressure waves originated somewhere east of New Jersey. The research team looked into historical tidal/water level and derecho records and found that a similar, though less energetic wave occurred in New England waters following the June 29, 2012 derecho event that followed an identical path to the ocean. The travel time of of this wave from the source (mid-Atlantic) to southern New England matches the 4.5 hour time from the June 13, 2013 event.

There were reports of injury and damage in the mid-Atlantic region, but tide gauge data indicate that the strongest wave response occurred in southern New England, in Narragansett Bay and on Cape Cod.

The possibility of a weather-triggered underwater landslide, which in turn generated or contributed to the tsunami, is also a possibility. More research is required to fully understand the source of the event.

The event was covered by several local news organizations. Their coverage, including interviews with URI GSO team members, may be found here.

Graph by NOAA/NOS/Center for Operational Oceanographic Products and Services