The 11 November 2018 Mayotte seismic event is a

seismic event An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fro ...

of unknown origin that occurred about off the coast of

Mayotte Mayotte (; french: Mayotte, ; Shimaore: ''Maore'', ; Kibushi: ''Maori'', ), officially the Department of Mayotte (french: Département de Mayotte), is an overseas department and region and single territorial collectivity of France. It is loc ...

, an

overseas department and region The overseas departments and regions of France (french: départements et régions d'outre-mer, ; ''DROM'') are departments of France that are outside metropolitan France, the European part of France. They have exactly the same status as mainlan ...

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

in the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

. It was recorded by seismograms globally, including in

Kenya ) , national_anthem = "Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

, and

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

, almost away. Despite this, no one felt it. The seismic waves lasted for over 20 minutes. Most earthquakes have P waves and

S wave __NOTOC__ In seismology and other areas involving elastic waves, S waves, secondary waves, or shear waves (sometimes called elastic S waves) are a type of elastic wave and are one of the two main types of elastic body waves, so named because th ...

s, which are later followed by long-period

surface waves In physics, a surface wave is a mechanical wave that propagates along the interface between differing media. A common example is gravity waves along the surface of liquids, such as ocean waves. Gravity waves can also occur within liquids, at th ...

. The Mayotte event lacked P waves and S waves, but did cause a long-period surface wave travelling at around the globe. Additionally, the signal released by the earthquake resembled a clean sine wave, while most earthquake waves have multiple frequencies.

Cause

The cause of the event was initially unknown, 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. The island of Mayotte had experienced hundreds of tremors since May 2018, including a magnitude 5.8 earthquake on 15 May. The quakes had been tapering off until the event occurred. Another possible explanation that was suggested was that

magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...

from a volcanic chamber approximately miles underneath the seafloor near Mayotte had suddenly drained, which could have led to the collapse of the roof of the chamber, causing the vibrations. In May 2019, a recently formed 800 meter high undersea volcano was found in the area of the event. This volcano is now assumed to have been the cause of the tremors.Starr, M. (30 September 2021)
Largest underwater eruption ever recorded gives birth to massive New Volcano.
ScienceAlert. Retrieved October 23, 2021.

References

* {{cite journal, last=Bhattacharya, first=S., date=2020, url=https://www.currentscience.ac.in/Volumes/118/07/1069.pdf, title=Source of unusual monochromatic wave packets recorded globally in the seismograms of 11 November 2018, journal=

Current Science ''Current Science'' is an English-language peer-reviewed multidisciplinary scientific journal. It was established in 1932 and is published by the Current Science Association along with the Indian Academy of Sciences. According to the ''Journal C ...

, volume=118, issue=7, pages=1069–1076, doi=10.18520/cs/v118/i7/1069-1076 2018 earthquakes November 2018 events in France