Three underwater robots have been launched by the University of Gothenburg in the Baltic sea close to the leakages on the Nord Stream gas pipelines. The robots would enable monitoring of the variation of life and chemistry over time due to the huge discharge of methane gas.
The underwater robots register data from the sea bottom to the surface non-stop. Image Credit: VOTO/Marcus Melin.
Skagerak, a research vessel is ready to be launched on a new mission to the Baltic Sea as a trial run for the big, unmanned vessel Ran. The mission with R/V Skagerak was not the only measure the university’s scientists took when methane gas seepage in the Nord Stream pipelines began.
With the assistance of the Voice of the Ocean (VOTO) Foundation, three remote-operated underwater robots were positioned in the area. They will travel through the sea and capture water data nonstop for the following 15 weeks.
They are called gliders and are provided by VOTO, who also manages their operation. The robots can give us measurements over a series of time about how the chemistry and quality of the water is affected by the natural gas leak.
Bastien Queste, Oceanographer, University of Gothenburg.
Plenty of Data from the Area
Since March 2021, VOTO has deployed two gliders in the area which work as one of its ocean observatories and where water quality is assessed continuously.
The robots travel down to the bottom and return to the surface. This is repeated over a pre-determined distance. Each time the glider comes to the surface, the most recent measurement data is transmitted to the scientists via satellite.
As a result, sufficient data from this area is already present. One of the three extra robots placed into the sea last week has been fitted by the manufacturer Alseamar with an exclusive sensor to assess the methane content variation during the following 15 weeks.
“Last week’s expedition provided valuable data and a snapshot of the state of the ocean immediately after the leakage occurred. With the new robots in place, we receive continuous reports on the state of the water near the Nord Stream pipeline leaks. They are deployed solely for this purpose,” states Bastien Queste.
The point is that we get measurements from the water over a long period of time and over a larger area. We can see how long it takes for the methane to disappear and how the aquatic environment reacts over time. The response in the sea is often delayed. It may take days or weeks before we see a change.
Bastien Queste, Oceanographer, University of Gothenburg.
The underwater robots typically launched there, can also provide crucial information as they measure oxygen content, temperature, salinity, and the quantity of chlorophyll. This concludes the picture of how the water in the Baltic Sea is progressing following the gas leak.
Solid Scientific Documentation
Together with the new robots and the expedition's measurements, we researchers will have solid scientific documentation of the impact of the Nord Stream leak. When we add it all up, we have a good picture of both the immediate and the delayed effects. With gliders that continuously measure, we will be able to better understand the processes that were observed then.
Bastien Queste, Oceanographer, University of Gothenburg.
The mission has hardly had time to come ashore before preparations for the subsequent trip to the Baltic Sea with Skagerak have commenced. Polar scientist Anna Wåhlin has planned to join the voyage for a long time to the region east of Bornholm.
“I will test how the large underwater robot Ran behaves in seas with large layers of density and how well it can measure over sediment-rich bottoms. This place is perfect for that. Ran will also be able to contribute to research into gas emissions because it measures the carbon dioxide and nitrate levels in the water,” says Anna Wåhlin.
This is also Ran’s first departure from Skagerak, which will be a crucial test of the ship's flexibility.
Source: https://www.gu.se/en