Implications for oceanographic and seafloor geodetic applications due to settling of self‐calibrating bottom pressure recorders

Ocean bottom pressure recordings are a key observation for both ocean circulation and seafloor geodesy. New self-calibrating instruments may solve a long-time issue of instrument drift, allowing new high precision observations. However, instruments on the seafloor may settle over days to months, potentially contaminating results. Here we present evidence for likely settling of two self-calibrating instruments deployed along the RAPID mooring array, on the order of 8–14 cm. Settling is expected, and we model the settling based on Terzaghi's consolidation theory, which is well known in civil engineering applications. After the settling correction the difference between the two pressure records has a standard deviation of ∼1 cm water height equivalent. Settling is likely an important factor that should be considered in oceanographic and geodetic experimental design. We recommend longer term deployments of 5–10 years to allow for settling and/or selection of sites with thinner sandy sediments to minimize settling.