Pressure, barometer and acceleration data from a 30-month deployment of the Geodetic and Seismic Sensor Module in Monterey Bay from June 2017 to December 2019

Geodetic observations in the oceans are important for understanding plate tectonics, earthquake cycles and volcanic processes. One approach to seafloor geodesy is the use of quartz crystal seafloor pressure gauges to sense vertical changes in the elevation of the seafloor after correcting for variations in the weight of the overlying oceans and atmosphere. The primary observational challenge of using pressure gauges is the tendency for the sensors to drift. The A-0-A method is a new approach for correcting drift. A value is used to periodically switch for a short time the measured pressure from the external ocean to the inside of the instrument housing at atmospheric pressure. The internal pressure reading is compared to an accurate barometer to measure the drift which is assumed to be the same at low and high pressures. This data set comprises pressure, barometer and accelerometer data from a 30-month test of the A-0-A method at 900 m depth on the MARS cabled observatory in Monterey Bay using an instrument that includes two A-0-A calibrated pressure gauges and a barometer manufactured by Paroscientific, Inc., and a three-component accelerometer manufactured by Quartz Seismic Sensors. Inc