Getting In the Acoustic Groove

On December 9, 2017, USGS Pacific Coastal and Marine Science Center in Santa Cruz, California set up displays and demonstrated equipment and data collection techniques at an Open House event. Here, USGS hydrologist Anthony Guerriero lets a visitor spin the propeller of a current meter that, when underwater, turns according to how fast the water pushes past it. You can "listen" to the ticking sounds that the current meter makes with each revolution of its propeller. The ticking sound is transmitted to a computer, and based on how many ticks per second are "heard" by the computer, water velocity (meters per second) can be calculated.