MultiBeam EchoSounder Enables First-of-its-kind Research
- The rotating head of the overview sonar, with the Sonic 2022 on it. (Photo taken with ROV Jason. Credits: UW/NSF-OOI/WHOI/MARUM, V18)
- Sonar Output Gas-emissions at the SHR (Credit: University of Bremen/MARUM/BMBf)
- The Overview sonar during tests in the saltwater tank of the University of Washington. (Credit: Yann Marcon, University of Bremen/MARUM)
Increasingly, methane emissions from the seafloor are of greater interest as concern over global warming increases.
Large quantities of the potent greenhouse gas methane are trapped within the seafloor in the form of so-called gas hydrates, solid ice-like deposits, which are only stable at particular conditions of high pressure and low temperature. As a result, only a small volume of methane bubbles up into the ocean, and therefore the quantity reaching the atmosphere is not threatening despite its greenhouse effect.
However, there is a concern that rising ocean temperatures could lead seafloor methane hydrate deposits to dissociate, which would result in a greater volume of methane released in the ocean, and potentially reaching the atmosphere, and therefore causing a high risk for humanity.
Scholars at the MARUM Center for Marine Environmental Sciences, University of Bremen, Germany, and the University of Washington in Seattle are working on a project initiated in 2017 called M3, funded by the German Ministry of Education and Research (BMBF) that monitors the natural release of methane at the Southern Hydrate Ridge (SHR) off the coast of Oregon State.
This real-time monitoring is performed by a MultiBeam EchoSounder (MBES), which until recently, was unconceivable due to the high power consumption of the MBES. The M3 project is made possible by R2Sonic’s MBES Sonic 2022, which offers high performances while ensuring low power consumption. The objective is to conduct this project over 2+ years in order to gather as much data as possible to help scientists determine if there is a relationship with ocean warming and volume of methane release in the ocean.
The Sonic 2022 deployed in June 2018 is mounted on a tripod that lays on the seafloor, and is connected to the Regional Cabled Array of the Ocean Observatory Initiative (OOI), an underwater cabled observatory funded by the National Science Foundation (NSF), which provides power supply and two-way communication to the instrument. The Sonic 2022 rotates 360° to survey the ocean for methane emissions in all directions.