SEA-KIT USV returns from caldera survey in Tonga

According to the team, USV Maxlimer brought back a ‘plethora of data and imagery’ that can fill important gaps in current understanding of the seamount and water above the volcano.

For the ongoing second phase of the NIWA/Nippon Foundation Tonga Eruption Seabed Mapping Project (TESMaP), funded by the Nippon Foundation, USV Maxlimer is equipped with a Multibeam Echo Sounder (MBES) to acoustically measure depth and state of the seabed. The vessel also has new winch capability for deployment of multiple sensors down to 300m, to obtain direct water column measurements.

Data collected using a Conductivity Temp Depth (CTD) instrument, deployed using the winch, is providing important temperature and salinity information as well as dissolved oxygen and turbidity readings. 

A Miniature Autonomous Plume Recorder (MAPR), designed to detect chemicals in the water that are common in hydrothermal plumes, is recording light-backscattering for suspended particle concentrations, oxidation reduction potential, temperature and pressure from multiple winch dips and tows. The MAPR project is a joint initiative between NOAA in the USA and GNS Science in New Zealand.