New type of tsunami hit US nuclear plant

6-foot tsunami that hit near New Jersey nuclear plant may be first of its kind in U.S.

People injured, swept out to sea by wave detected as far as Puerto Rico — NOAA said continental shelf may have slumped, now suspects ‘atmospheric event’

ENENews,

23 December, 2013

2014 Ocean Sciences Meeting — CODAR Ocean Sensors & Rutgers University, Dec. 14, 2013: Tsunamis are generally thought of as low-frequency waves that are generated by an underwater disturbance be it an earthquake or landslide. A tsunami can also be generated by an atmospheric disturbance such as a rapid pressure change. These tsunamis are referred to as meteotsunamis because of their meteorological origin. A meteotsunami was detected and tracked off the coast of New Jersey on June 13, 2013. [...]

CODAR Newsletter, Fall 2013: A strange series of blogs and anecdotal community gossip described people getting swept off breakwaters and out to sea in New Jersey on June 13. It received only local attention for several days. Later someone put these together with an unusual storm system [...] and proposed it may have launched a “meteotsunami” [...] rarely mentioned in the U.S. [NOAA] stepped in to investigate this 13 June event, and put forward another possible origin besides meteorological: an undersea landslide in the Hudson Canyon. The fact that it was indeed a tsunami was confirmed by 30 tide gages [sic] along the East coast up through New England, and as far away as Puerto Rico. [...] A panel of scientists was convened by NOAA to study this event [...] A number of tentative conclusions were reached [...] The tsunami was definitely spawned by the “derecho” atmospheric event depicted in the first figure, not an undersea landslide. [...] this event is considered a “first” in the U.S., supported by extensive observations and modeling [...]

NPR report from two weeks after the event: NOAA: A Rare Tsunami Hit The East Coast [...] The West Coast and Alaska Tsunami Warning Center said the source of the wave is “complex and under review,” but they believe it was caused by a strong storm and perhaps even the “the slumping at the continental shelf east of New Jersey.”

NOAA’s National Weather Service: A first-hand description was provided by Brian Coen who observed the event at Barnegat Inlet in New Jersey: Around 3:30pm on Thursday June 13, 2013, Brian Coen was spear fishing near the mouth of Barnegat Inlet [...] At approximately 3:30, the outgoing tide was amplified by strong currents which carried divers over the submerged breakwater (normally 3-4 feet deep). This strong outrush continued for 1-2 minutes and eventually the rocks in the submerged breakwater were exposed. Brian backed his boat out before being sucked over as well. At this point, Brian noticed a large wave coming in, approximately 6 feet peak-to-trough and spanning across the inlet. The upper 2 feet of the wave was breaking. This wave occurred in conjunction with a reversal of the current such that even though the tide was going out, a strong surge was entering the inlet. This surge carried the divers back over the submerged reef and into the inlet from where they were picked up. On the south jetty three people were swept off the rocks which were 5 to 6 feet above sea level at the time. At least two were injured requiring medical treatment. [...]

Watch NOAA’s latest simulation of the tsunami published Dec. 9, 2013 here