The Earth Always Hums: Microseisms, with passing ships and whales (acceleration x360)
Left: The spectrogram of the microseisms (the broad bright band on the left). The spectrogram shows the signal strength—or how loud it is—over time and at different frequencies. Labels and scales appear periodically. One of the horizontal scales at bottom left shows the original period of the signal, measured in seconds. This signal is inaudible to the human ear. The recording has been accelerated by a factor of 360, bringing it into the audible range. The frequency scale (bottom left) marks the frequency (Hz) of the transformed signal that we hear. The faint thin lines and intermittent thick lines on the right of the spectrogram are the sounds of passing ships and fin whales, respectively. Right: the 3D visualization of the sound.
This stereo track is a rendering of the 3 components of the motion of the seafloor at a 3.9 km depth, southwest of Ireland. The seismograms were recorded on 19 April, 2020, by the ocean-bottom seismic station Brian of the SEA-SEIS network.