View source for Unsolved:11 November 2018 Mayotte seismic event

The '''11 November 2018 Mayotte seismic event''' is a seismic event of unknown origin that occurred about {{Convert|15|mi|km|order=flip}} off the coast of Mayotte, an overseas department and region of {{wipe|France}} in the [[Earth:Indian Ocean|Indian Ocean]]. It was recorded by [[Earth:Seismogram|seismogram]]s in many countries, including Kenya, {{wipe|Chile}}, [[Earth:New Zealand|New Zealand]], {{wipe|Canada}}, and Hawaii, almost {{Convert|11,000|mi|km|order=flip}} away.<ref name=forbes/> Despite this, no one felt it. The seismic waves lasted for over 20 minutes.<ref name=":0"/> Most earthquakes have [[P-wave]]s and [[S-wave]]s, which are later followed by long-period surface waves. The Mayotte event lacked P-waves and S-waves, but did cause a long-period surface wave<ref name=bigthink>{{cite web|url=https://bigthink.com/surprising-science/mystery-seismic-wave?rebelltitem=1#rebelltitem1|title=An unexplained seismic event 'rang' across the Earth in November|author=Robber Berman|accessdate=2019-01-26|date=2018-11-29|publisher=The Big Think Inc.}}</ref><ref name=newsltd/> travelling at {{cvt|9000|mph|order=flip}} around the globe.<ref name=forbes>{{cite web|url=https://www.forbes.com/sites/trevornace/2018/12/03/strange-waves-rippled-across-earth-and-only-one-person-spotted-them/#20938576aaab|title=Strange Waves Rippled Across Earth And Only One Person Spotted Them|author=Trevor Nace|accessdate=2019-01-26|work={{wipe|Forbes}}|date=2018-12-03}}</ref> Additionally, the signal released by the earthquake was a clean "zigzag," while most earthquake waves have multiple frequencies.<ref name=":0">{{Cite news|url=https://www.nationalgeographic.com/science/2018/11/strange-earthquake-waves-rippled-around-world-earth-geology/|title=Strange waves rippled around the world, and nobody knows why|publisher=National Geographic|author=Maya Wei-Haas|date=2018-11-28|access-date=2018-11-30}}</ref>

== Cause ==
The cause of the event was initially unknown,<ref name=newsltd>{{cite web|url=https://www.news.com.au/technology/science/strange-seismic-waves-were-picked-up-circling-the-globe-on-november-11-now-seismologists-are-trying-to-figure-out-why/news-story/31a4e88570f95dfea9e1a0fe7a7daf2e|title=Strange seismic waves were picked up circling the globe on November 11. Now seismologists are trying to figure out why|date=2018-11-29|accessdate=2019-01-26|publisher=News Limited}}</ref><ref>{{cite web|url=https://www.bustle.com/p/unusual-seismic-waves-shook-the-earth-on-nov-11-scientists-still-dont-completely-know-why-13221267|title=Unusual Seismic Waves Shook The Earth On Nov. 11 & Scientists Still Don't Completely Know Why|author=Lucia Peters|accessdate=2019-01-26|date=2018-11-29|publisher=Bustle Digital Group}}</ref> but scientists from the French Geological Survey believe it may have been caused by an underwater volcano, and also related to an earthquake swarm nearby.<ref name=":0" /> The island of Mayotte had experienced hundreds of tremors since May 2018, including a [[Richter magnitude scale|magnitude]] 5.8 earthquake on 15 May. The quakes had been tapering off until the event occurred.<ref name=bigthink/>

Another possible explanation that was suggested was that [[Biology:Magma|magma]] from a volcanic chamber approximately {{cvt|10|mi|order=flip}} miles underneath the seafloor near Mayotte had suddenly drained which could have led to the roof of the chamber to collapse causing the vibrations.<ref name=guardian>{{cite web|url=https://www.theguardian.com/science/2018/nov/30/magma-shift-mysterious-seismic-wave-event-mayotte|title='Magma shift' may have caused mysterious seismic wave event|work={{wipe|The Guardian}}|year=2018|accessdate=2019-01-26}}</ref>

In May 2019, an 800 meter high undersea volcano was found that was not there before. This volcano is now assumed to have been the cause of the tremors.<ref>{{cite web|url=https://www.sciencemag.org/news/2019/05/ship-spies-largest-underwater-eruption-ever|title=Ship spies largest underwater eruption ever|author=Roland Pease|accessdate=2019-05-22|date=2019-05-21|work=Science}}</ref>

== References ==
{{Reflist}}
Source of unusual monochromatic wave packets recorded globally in seismograms of 11 November 2018.  Current Science, v. 118 (2020) pp.&nbsp;1069-1076.

[[Category:Earth mysteries]]

{{Sourceattribution|11 November 2018 Mayotte seismic event|1}}