Residents of the Indian Ocean island of Mayotte began 2020 with a return to the seismic shaking associated with an undersea volcano that has been testing their patience since 2018.

The latest quake was a magnitude-5.0 at 7 p.m. local time Thursday, according to the French Central Seismological Office (BCSF-ReNaSS). It happened 26 kilometers offshore from Mamoudzou at a location where thousands of small earthquakes have been recorded these last two years, but it is the largest to shake the island in months.

The widely-felt tremor has residents wondering if that – and a comparable quake on Wednesday – herald a new round of increased volcanic activity.

“The volcano has awakened a little after a calm period of several months,” said a Koungou resident, one of dozens to report their experiences at the European-Mediterranean Seismological Centre website.

“The trembling was long, and on the second floor the windows vibrated, the walls trembled and the closet doors slammed,” said one in Pamandzi.

“Strong and long shaking on (our) small land,” another Pamandzi resident added. “The children started to be afraid again.”

That’s significant in Mayotte, where damage from the seismic swarm has been light over time, but authorities need to deal with the fears of affected residents and at one point opened a psychological support line for people having difficulty coping with the tremors.

Mayotte’s experience began on May 10, 2018, with a magnitude-5.8 quake five days later that was the largest ever recorded in the Comoros basin. Mayotte is part of the Comoros group of islands but remains a French territory, located at the northern edge of the Mozambique Channel between the southern African mainland and Madagascar.

A team of international scientists, led by French agencies and researchers, announced the discovery of the new volcano in May 2019. They said the new volcano is located 50 kilometers east of the island and 3500 meters below the surface, standing about 800m high with a base between four and five km in diameter.

The undersea volcano was spewing material to a height of two kilometers below the surface, and the volcano is linked to a rapid rate of shifting and sinking of Mayotte, the French government said. Scientists continue to explore the site and potential impacts of this emerging volcano.

Image: MAYOBS file