Transient thermal response in ocean bottom pressure measurement

Offshore ocean bottom pressures usually follow ocean tidal motion but sometimes deviate from it even when no tsunami occurs. Numerous observations suggest that such deviations highly correlate with sudden temperature changes, probably due to irregular deep ocean currents, around the pressure gauges regardless of static temperature compensation mechanism. We ascribe this deviation to the transient thermal response of the pressure gauges, which produce apparent pressure fluctuations when temperature change quickly so that temperature equilibrium condition of two quartz transducers is not valid. We put forward an empirical method to estimate the transient thermal response correctly. Such rapid temperature change may have to be corrected for a robust tsunami warning based on offshore tsunami observation with pressure gauges.