Real-time measurements provided by pressure sensors on the seafloor are of great importance because lunar tides, storms, and currents can impact fluid migration into and out of the seafloor crust and sediments. This “pumping” of seawater into the porous chimney walls and the seafloor in hydrothermal systems causes mixing with high temperature hydrothermal fluids and results in an energy-rich environment for microbial communities. The pressure sensors can also measure the passing of tsunamis in real-time.
Sea-Bird SBE 54 seafloor pressure sensors are installed at Axial Base (MJ03A), Slope Base, (MJ01A), and the Southern Hydrate Ridge Summit (LJ01B). Pressure on the Cabled Array is also measured very near the seafloor by the HPIES instruments at Slope and Axial Base, with CTDs on the Benthic Experiment Platforms at the Oregon Shelf and Offshore sites, and on the Bottom Pressure and Tilt instruments at the summit of Axial Caldera.
Pressure sensors are also a component of the CTDs on the instrumented Shallow Profiler Moorings and Mclane vehicles on the Deep Profilers, providing information on where the platforms are in the water column.