A tsunami buoy off the New Jersey coast went into "event mode" Sunday night, raising concerns after it recorded a very steep wave reading while undergoing maintenance.
Texas Tower No. 4 Station 44066 — a tsunami buoy located about 75 nautical miles east of Long Branch, New Jersey — recorded a sudden change of about 55 meters in water depth in a matter of seconds. A report on New York-based Superstation95’s website was shared across social media overnight.
"Event mode" occurs when the algorithm on the Bottom Pressure Recorder (BPR) detects info more often — every 15 seconds is possible — due to sudden activity.
The seemingly seismic event, which occurred around 22:38 UTC (6:38 p.m. Eastern Time), raised fears among community members.
But no, it wasn’t an earthquake — the nearest quake, recorded off the coast of Punta Cana, Dominican Republic, about 10 minutes later, was unrelated — nor was some super wave headed for the Jersey Shore.
The event was actually caused by routine maintenance work being done to the buoy, the National Data Buoy Center (NDBC) told NBC10 Monday morning.
Often, the NDBC will turn off the buoys while work is being done to avoid causing concern like what happened in this case, said the Mississippi-based NDBC.
"Not every Event is a tsunami," says the NBDC website. "In some cases, it can go into Event Mode because of electronic problems, or during the recovery of a BPR. The tsunami warning centers can initiate an event to have the tsunameter report more frequently in anticipation of tsunami. Events are usually initiated by the seismic signal from an earthquake, and the actual tsunami, if there is one, will pass the tsunameter later. It requires expert analysis to determine a tsunami from the tsunameter data."
The NDBC works on buoys about once a year.