Geologists Discover Largest Underwater Volcano
A strange seismic event off the coast of Africa has led scientists to a mighty finding: the discovery of the largest underwater volcanic eruption ever recorded.
The eruption also may explain a weird seismic event recorded in November 2018 just off the island of Mayotte, located between Madagascar and Mozambique in the Indian Ocean. Researchers described that event as a seismic hum that circled the world, but no one could figure out what sparked it.
For starters, the hum rang at a single, ultralow frequency, which was strange because seismic waves usually rumble at many frequencies. Moreover, there were hardly any detectable “p-waves” or “s-waves,” which usually accompany earthquakes. And, incredibly, 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 weird seismic hum was likely the birth announcement of a new underwater volcano, according to Science magazine.
The underwater volcano is enormous, rising nearly a half mile (0.8 kilometers) from the ocean floor. It’s the length of a 3.1-mile (5 km) race and lies about 31 miles (50 km) off Mayotte’s eastern coast. And it came into being in just six months.
“We have never seen anything like this,” Nathalie Feuillet, a leader of an expedition to the site by the research vessel Marion Dufresne, who is with the Institute of Geophysics in Paris (IPGP), told Science magazine.
In addition to the weird “seismic hum,” there were other clues that something big was happening. The inhabitants of the French island of Mayotte reported feeling more than 1,800 little earthquakes almost daily since the middle of last year, including a large magnitude-5.8 earthquake in May 2018, the largest ever recorded in the region, National Geographic reported.
How scientists found it
Finding the newborn volcano took an enormous effort, including work from organizations such as the National Center for Scientific Research (CNRS) in France, the IPGP and the French Research Institute for the Exploitation of the Sea (IFREMER), according to a joint statement released May 16.
Part of that research included six seismometers placed on the ocean floor, close to the seismic activity, Science magazine reported. These instruments revealed a tight cluster of earthquakes deep in Earth’s crust, likely stemming from a deep magma chamber that’s gushing molten rock onto the sea’s bottom.
This magma chamber may also be shrinking, as Mayotte has sunk about 5 inches (13 centimeters) and moved 2.5 inches (10 cm) to the east over the past year, Science magazine reported.
In addition, sonar revealed 1.2 cubic miles (5 cubic km) of magma on the seafloor, as well as plumes of bubble-rich water streaming from the volcano. Rock samples collected from the site may reveal the depth of the magma source, as well as the risk of a volcanic eruption.
A volcano in the Indian Ocean?
Mayotte isn’t a stranger to volcanic eruptions, but it’s been at least 4,000 years since volcanoes last stirred in the area, National Geographic reported. The island is part of the Comoro archipelago, islands created by volcanism. [Sunset Crater: Spectacular Photos of a Cinder Cone Volcano]
As news of the seismic hum and the tiny earthquakes spread, a group of French researchers posted a draft of a research study on EarthArxiv, a non-peer-reviewed site in February 2019, positing that the rumblings might have to do with a draining magma chamber. But researchers still have to publish a peer-reviewed study on the events, and it remains unclear exactly how the weird hum, earthquakes and volcano are related.
It’s also a mystery why volcanoes are found near the tiny island. Unlike Hawaii, which formed because of hotspot volcanism roiling up, the volcano near Mayotte lies within the ancient rift where Madagascar tore away from eastern Africa long ago. It’s possible that fissures from this break are now a cradle for this new volcano. However, it’s strange that the volcano popped up by Mayotte, which is the oldest island in the archipelago, Ken Rubin, a volcanologist at the University of Hawaii at Mānoa, told National Geographic.
It also remains to be seen if this volcano is completely new, or whether it sits on an older volcanic structure, the researchers said. In other words, geologists have a lot of work to do, and they’re eager to get to the bottom of this geologic conundrum.
Read more at www.livescience.com
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FauxScienceSlayer
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“Volcanic CO2” by Timothy Casey at Geologist-1011
Seafloor rift gas discharges are below the P-V-T limit for gases and are converted to liquids. There are vast pools of liquid CO2 and Methane on the ocean floors.
“Earth’s Missing Geothermal Flux” > FauxScienceSlayer
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Jim Kamis
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You may want to review two articles which address the lack of information concerning the geological setting of our planet’s ocean floors. Ocean floors which comprise 71% of earth’s surface. “How Major Geological Events End So-Called Glacial Periods” @ Principia Scientific. Also “How Major Oceanic and Continental Fault Boundaries Act to Control Much of Earth’s Climate” @ plateclimatology.com. These articles provide information showing that the power, geographical distribution, and climate influence of ocean floor geological features and their associated fluid emissions are very poorly understood.
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Robert Beatty
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Jim,
Your articles make a lot of sense, but I wonder if the hot water pattern you show coming from the PNG – Solomon Islands region might be going the opposite way? The south equatorial current travels from east to west and there are satellite images showing the hot water may come from plumes sited on the west coast of south america. see
http://strata-sphere.com/blog/index.php/archives/18084
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Jim Kamis
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Robert,
Review of the following time lapse video of El Nino development including time lapse cross-sectional views may answer your question. This and many other pieces of information and research have formed the basis of my contention that massive pulses of geologically induced heat and chemically charged heated fluid flow from ocean floor features located in the PNG and Solomon Island area generate and maintain El Nino’s. A few other geologists concur with this idea. However, current scientific theory does not concur with a geological origin of El Nino’s, instead favoring atmospheric forces. (https://www.youtube.com/watch?v=gaFjlZxM7S4)
Regards,
Jim
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Robert Beatty
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Jim,
I note your comment “my contention that massive pulses of geologically induced heat and chemically charged heated fluid flow from ocean floor features located in the PNG and Solomon Island area”, but it is unlikely there is only one driver as such ocean floor features are not uncommon. I think the NOAA time lapse shown at:
https://www.ospo.noaa.gov/Products/ocean/cb/dhw/anim_6mp.html
also shows a relevant plume originating above a known subduction zone off the west coast of South America. The bottom line seems to be tectonic activity on the sea floor affects the weather in a quite dramatic way.
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