Axial seamount - restless, wired and occupied: A conceptual overview of resident AUV operations and technologies

摘要

The Ocean Observatories Initiative Cabled Array has provided an unprecedented real-time window on the dynamics of Axial Volcano since fall 2014. In April and May of 2015, for the first time, researchers on shore were able to monitor an eruption event as it happened. The seismic, deformation and acoustic signals sent to shore were analyzed to determine the precise locations of diking events, followed hours later by acoustic impulses corresponding to lava expulsion from the seafloor. Although these locations informed follow-up Autonomous Underwater Vehicle (AUV) mapping expeditions which produced high resolution bathymetry, to date, the evolution of an eruptive event and its immediate impact on the surrounding ecosystem have not been observed. Although the 70,000 km-long mid ocean ridge (MOR) must generate many hundreds of powerful, transient events every year, they have never been characterized as they form. We envision a Resident AUV with in situ charging and data download capabilities, shore-based mission control, and an array of bottom-mounted acoustic positioning beacons that can concurrently be used as a multi-hop sensor network. This system will provide unprecedented observing capabilities before, during, and after the next eruption and formation of the highly energetic eruptive (mega) plume. AUV capabilities will include high-resolution bathymetry, high definition video and still imagery, and 3-D water chemistry and microbial sampling throughout the water column, while the acoustic array will monitor horizontal and vertical deformation.