Odd seismic waves have been detected around Earth with no apparent source

James Marshall
December 1, 2018

Seismic waves buzzed sensors from Africa to New Zealand and Hawaii for about 20 minutes, but it seems no humans felt the freakish ripple, National Geographic reported. It seems that only devices like the real-time seismogram in the US Geological survey detected them. Magma might be on the move deep below the ocean some miles from the shores.

As no humans felt, they went undetected at the time.

This is a most odd and unusual seismic signal.

Some scientists think the weird ripple might be something to do with a seismic storm lashing Mayotte, an archipelago in Africa near where the signal began. But this didn't appear to have the same characteristics as a regular quake.

In case of a typical natural disaster, the rapid crash of a tectonic plate movement sends out what is known as a "wave train" which is composed of several types of waves moving at different speeds from the epicentre of the quake. After P waves come the secondary waves or S waves and finally slower low-frequency surface waves. Second, the wave emerged and circled the planet without the usual signs of an natural disaster; no one in the area felt any shaking, and the "p-waves" and "s-waves" associated with the hum, the sort of waves that you actually feel during an quake, were so faint as to be almost undetectable. He thinks it passed by surreptitiously because it was a slow quake. But interestingly there had been no perceptible natural disaster in Mayote. The waveform was a crisp zigzag, which repeated after steady 17-second intervals.

What do the scientists say? "It is very hard, really, to say what the cause is and whether anyone's theories are correct", Helen Robinson, a doctoral candidate in applied volcanology at the University of Glasgow, told National Geographic. "They're too ideal to be nature".

Geologists shared their discovery of the surprisingly low frequency activity on Twitter, with Jamie Gurney, the founder of the UK Earthquake Bulletin, among the first to note the event.

Seismologist Göran Ekström from Columbia University told National Geographic 'I don't think I've seen anything like it'.

He added: 'It doesn't mean that, in the end, the cause of them is that exotic'.

Other reports by Click Lancashire

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