Senior Scientist Aaron Micallef and researchers in MBARI’s Seafloor Processes Team work closely with MBARI engineers to develop innovative technologies that are transforming our understanding of the processes that shape the seafloor. 

Geo-Sense uses distributed acoustic sensing (DAS) for high-resolution monitoring of seafloor processes. By measuring the phase changes in laser light along the cable, scientists can detect disturbances on the seafloor, including earthquakes, underwater landslides, and fluid seepage. MBARI scientists have completed several successful deployments of Geo-Sense in Monterey Canyon. The HYDROSENSE expedition marks the first international application of this innovative new instrument.

During MBARI’s recent Multisensory Milos expedition, the team conducted a calibration test of DAS instruments in Paleochori Bay, where hydrothermal activity drives the release of gas bubbles from the seafloor. Using a portable DAS interrogator, the team was able to refine data analysis techniques for detecting volcanic and hydrothermal processes. 

For the HYDROSENSE expedition, Geo-Sense will be outfitted with a 500-meter (1,640-foot) fiber-optic cable to detect seafloor processes in and around the Kolumbo crater. Hydrophone records, submersible surveys, multibeam mapping data, and seafloor and CTD sampling will complement the DAS data, providing incredibly detailed insights into submarine volcanic unrest that can guide future research and monitoring efforts at Kolumbo.

MBARI’s MiniROV is a small remotely operated vehicle (ROV) designed as a self-contained, easy-to-transport ROV system for use on ships of opportunity. The MiniROV’s flexibility allows researchers and engineers to use this vehicle to work in the Monterey Bay and beyond, from the ocean’s surface to 1,500 meters (about 4,900 feet) deep.

The expedition team will use the MiniROV to survey the Geo-Sense cable, then collect detailed video observations of seafloor geology and biological communities. The MiniROV is equipped with cameras, a robotic arm, a tray of pushcores, and a specimen drawer. MBARI’s skilled ROV pilots will operate the vehicle from a portable control room aboard the research vessel Gaia Blu and collect sediment samples that the expedition can examine in the lab aboard the ship to characterize seafloor communities.

Principal Engineer Giancarlo Troni and engineers in MBARI’s CoMPAS Lab develop scalable marine technology that can be easily modified for use across a wide variety of vehicles and platforms. The lab’s Portable Mapping System (PoMS) is a versatile and cost-effective tool for seafloor mapping and monitoring. Prior to the expedition, MBARI engineers outfitted the MiniROV with the Benthic Mapping and Sampling Sled configuration of PoMS, which will allow the expedition team to collect high-resolution 3D mapping data about Kolumbo and its surroundings that will complement the data collected by Geo-Sense.

Using the sled’s top-down and forward-looking sensors, the team will be able to produce 3D reconstructions of multiple complex structures, such as hydrothermal vent chimneys. Beyond mapping, CoMPAS Lab engineers plan to use their own precision navigation and control system to command the vehicle during deployment and surveys.