Buoy Test No Cause for Alarm

LONG BRANCH – A tsunami buoy located about 75 nautical miles east of Long Branch, N.J. went into “event mode” around 6:38 p.m. Eastern Time April 24, raising concerns after it recorded a steep wave reading, according to a report on NBC 10 Philadelphia.
Texas Tower No. 4 Station 44066 recorded a sudden change of about 55 meters in water depth in a matter of seconds. 
According to the report, “event mode” occurs when the algorithm on the Bottom Pressure Recorder (BPR) detects information more often — every 15 seconds is possible — due to sudden activity.
National Data Buoy Center (NDBC) told NBC 10 Philadelphia the activity was caused by routine maintenance work being done to the buoy. NDBC works on buoys about once a year, and typically turns off the buoys while work is being done to avoid concern like what happened Sunday.
According to NDBC’s website, “Not every Event is a tsunami. 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.”