Tsunameter

A tsunameter is the seafloor bottom pressure recorder at the heart of a DART tsunami-detection station. Anchored on the deep ocean floor, it samples water pressure at high resolution and detects tsunami waves as small as 1 cm in amplitude through 6000 m of water by sensing the pressure of the overlying column. It runs predictive de-tiding to flag anomalous pressure changes, switching from a 15-minute standard mode to a 15-second event-reporting mode when a wave is detected. An acoustic modem relays the data to the companion surface buoy, which transmits it by satellite to tsunami warning centers within minutes.