Temporal Magnetic Surveys using Autonomous Underwater Vehicles

High resolution magnetic surveys of the seafloor have become more ubiquitous in recent times with the broad application of autonomous underwater vehicles (AUV) to seafloor investigation.  AUVs can follow a precise path repeatedly which allows to the possibility of repeated measurements through time. This provides unique insight in what was considered mostly static seafloor magnetic properties. Some examples of dynamic magnetic field include anomalies associated with recent lavas cooling and becoming magnetized, while deep-seated thermal anomalies associated with magma chambers may demagnetize the overlying crust and create a detectable signal at the seafloor if not the sea surface.  We present an update to a temporal magnetic study of Axial seamount in the northeast pacific.  Axial Seamount is active having erupted in 2015, 2011, and 1998. Axial is part of the Ocean Observatory Initiative Regional Cabled Array.  Magnetic field is not monitored but repeat, semi-yearly surveys have been done by AUV Sentry for geodetic purposes which happily also collects magnetic field data. We present recent 2024 results from Axial Seamount as it inflates for a future eruption.