On the potential for automated realtime detection of nonlinear internal waves from seafloor pressure measurements

Because of the large forces they exert, large amplitude, highly nonlinear internal waves (NLIWs) represent a potential danger for offshore structures. This threat has prompted expensive operational observations to guarantee the safety of drilling platforms. The potential for automated detection using seafloor pressure measurements is investigated here, using data from New Jersey’s continental shelf. The detection algorithm is first tested using the complete time series. Detection in the pressure record is verified by comparison to coincident velocity measurements permitting identification of false positives and false negatives. The detection algorithm achieves 100% success for NLIWs with pressure amplitude >250 Pa, roughly equivalent to vertical velocity 0.1 m s−1, or a moderately energetic NLIW on New Jersey’s continental shelf. Executed in pseudo-realtime mode, to simulate an automated detection scheme, waves >250 Pa are accurately detected with 1 h delay.