Friday Find: Mystery tide and tsunami detector

Calling all extreme ocean buffs and seafarers! The NOAA Heritage Program needs your help. Email us at [email protected] if you have information on this instrument!

Tsunameter used on USC&GS Ship Pathfinder until 1970 to warn of impending tsunamis. (Image credit: NOAA Heritage)

NOAA Heritage Homepage

This instrument recently surfaced in NOAA’s heritage collection. The tag attached to the device identifies it as a tsunami detector and alarm that was removed from the U.S. Coast and Geodetic Survey (USC&GS) Ship Pathfinder when it was decommissioned in 1970.

Our research indicates that this is likely a type of U-tube manometer used with tide gauges. However, it is unclear who designed it or how and where USC&GS may have used it. There is also a handwritten note describing a bit about its operation.

The note reads, “Tsunami detector sets off alarm when water rises too fast in tide gauge well which has been capped. Wooden box is original design. Lucite box is replacement design, which was in turn replaced by existing (1974) system. Mercury rising in tubes makes electrical contact which sets off alarm.”

Do you know about this instrument or ones like it? If so, we’d love to hear from you!

NOAA Heritage Homepage