They covered an area of roughly 965 square miles. The instruments measured the speed and direction of currents every 10 minutes for four years. The company shared the data with the researchers.
Lewis Bailey, a geoscientist from the University of Calgary, analyzed the data from the ADCPs and noticed that the results looked very different from the trend of steady northward currents that was expected.
But after examining the data further, the researchers found that the seafloor currents would often speed up, slow down, and even reverse direction.
They wanted to get down to the bottom of what was causing these patterns of variation. It turned out that the currents changed throughout the seasons and tidal cycles.
The ADCPs and the patterns they picked up from the seabed showed that currents on open seafloor slopes generally flowed northward. But within submarine canyons, which usually face east-west, the currents often reverse direction.
The researchers suspected that the seafloor topography and the tides are mostly in command of the character of the currents.
Scientists depend on studies of ocean currents to determine how sediments and pollutants, such as microplastics, are transported and how they might affect deep-sea ecosystems. The studies also help with reconstructing ancient ocean conditions.
The details of the recent findings were published in Nature Geoscience.
