Acoustic imaging of hydrothermal plumes, East Pacific Rise, 21°N, 109°W

Publisher Website
Google Scholar
Abstract
We report the first observations based on acoustic imaging of large‐scale structure and time variability of buoyant plumes emanating from black smoker‐type seafloor hot springs. Three‐dimensional plume reconstructions were made from a digital data set of acoustic backscattering information recorded on a prototype submersible‐mounted sonar system. The acoustic images of two adjacent black smokers depict volume and show zones of flow organization (meters to tens of meters) in the lower 40 m of the buoyant plumes. The two plumes coalesce, bend in the prevailing current, exhibit short‐term (minutes) variation in cross section, and rapid (seconds) turbulent eddy variations at small scales (< 1 m). The plume imaging system is being developed for determination of plume dynamics, flux determinations when combined with chemical and thermal measurements, and long‐term monitoring of the activity of seafloor hydrothermal fields.