[ad_1]
A strange seismic event off the African coast led scientists to a major discovery: the discovery of the largest underwater volcanic eruption ever recorded.
The eruption could also explain a strange seismic ring recorded in November 2018 off the island of Mayotte, located between Madagascar and Mozambique in the Indian Ocean. The researchers described this event as a seismic buzz that went around the world, but no one could understand what had caused it.
For starters, the buzz sounded at a single ultra-low frequency, which was odd because seismic waves usually resonate at multiple frequencies. In addition, there was virtually no detectable "p-wave" or "s-wave" that usually accompanies earthquakes. And, incredible thing, the island of Mayotte moved a few inches south and east after the mysterious event. [Photos: Hawaii’s New Underwater Volcano]
Now scientists have an idea why. This strange seismic buzz was probably the announcement of the birth of a new submarine volcano, according to Science magazine.
The submarine volcano is huge and rises to almost 800 meters from the bottom of the ocean. It is the length of a 5 km run and is located about 50 km from the east coast of Mayotte. And he was born in just 6 months.
The submarine volcano is located off the east coast of the island of Mayotte (part of which is presented here).
Credit: Insularis via iStock / Getty Images More
"We have never seen anything like it," Nathalie Magazine, Nathalie Feuillet, Nathalie Scribe, a researcher at the Paris Institute of Geophysics (IPGP), said in an interview with research vessel Marion Dufresne. .
In addition to the "seismic buzz", there were other clues that something big was going on. Residents of the French island of Mayotte reported having felt more than 1,800 small earthquakes almost daily since the middle of last year, including a major magnitude 5.8 earthquake in May 2018, the largest recorded in the region, according to National Geographic.
How scientists found it
The research of the newborn volcano has required a huge effort, including work of organizations such as the National Center for Scientific Research (CNRS) in France, the IPGP and the French Institute of Research for the Exploitation of the Sea (IFREMER), according to a joint statement released May 16.
Part of this research included six seismometers placed at the bottom of the ocean near seismic activity, Science magazine reported. These instruments revealed a series of deep earthquakes in the Earth's crust, probably originating from a deep magma chamber that projects molten rocks onto the seabed.
The magmatic chamber could also contract, Mayotte sank about 13 centimeters and moved 10 centimeters east over the past year, Science magazine reported.
In addition, the sonar revealed 5 cubic km of magma on the bottom of the sea, as well as plumes of water rich in bubbles springing from the volcano. Rock samples collected at the site can reveal the depth of the magma source, as well as the risk of a volcanic eruption.
A volcano in the Indian Ocean?
Mayotte is no stranger to volcanic eruptions, but it has been at least 4,000 years since volcanoes did not move in the region, National Geographic reported. The island is part of the Comoros archipelago, islands created by volcanism. [Sunset Crater: Spectacular Photos of a Cinder Cone Volcano]
As rumors of earthquake buzz and small earthquakes spread, a group of French researchers published in February 2019 a research project on EarthArxiv, a non-peer-reviewed site, claiming that rumors could be linked to a draining magma chamber. However, researchers still have to publish a peer-reviewed study of events, and we still do not know how strange noises, earthquakes and volcanoes are linked.
It's also a mystery why volcanoes are found near the small island. Unlike Hawaii, which formed because of the hotspot volcanism, the volcano near Mayotte is in the old fault where Madagascar had torn East Africa long ago. It is possible that the cracks of this rupture are now a cradle for this new volcano. However, it is strange that the volcano appeared near Mayotte, which is the oldest island in the archipelago, told Ken National, Ken Rubin, a volcanologist from the University of Hawaii in Mānoa.
It also remains to be seen if this volcano is completely new or based on an older volcanic structure, the researchers said. In other words, geologists have a lot of work to do and they can not wait to get to the bottom of this geological puzzle.
Originally published on Science live.
[ad_2]
Source link