ah....mega volcano just east of Mayotte
Remember that 17sec wave noted 11-11-18 did not look like a natural phenomenon at the time - too regular -
>https://www.nationalgeographic.com/science/2018/11/strange-earthquake-waves-rippled-around-world-earth-geology/
A Steady 17 Seconds
"Most earthquakes send out waves with a slew of different frequencies, but mayotte's signal was a clean zigzag dominated by one type of wave that took a steady 17 seconds to repeat."
Later, NatGeo later brushed that away (ignoring the regularity), in Spring 2019, attributing it to volcanic activity: https://www.nationalgeographic.com/science/article/strange-waves-rippled-around-earth-may-know-why
Look at this NEW ARTICLE:
"Between 25 February and 6 May 2019, this network detected17,000 seismic events...."
REALLY??