See 403 for Lisa Mei's take on the waves.
The waves are a given. They were detected independently at many seismic sensor stations around the world, apparently all consistent with a real seismic event near Mayotte Island off Madagascar. Having to use different satellites for communication doesn’t affect the transmission of a real seismic event along the surface of and through the earth.
The 17-second intervals between the seismic impulses represent a strange Q-incidence, but I don’t see yet how human interventions can produce seismic events miles below the surface of the earth.
[Sorry for my earlier misread. The seismic wave frequency was not 17 Hz as I thought earlier, but 1 per 17 seconds, or 1/17 Hz.]