French island Réunion sits above one of Earth's plumes in which one of its two massive volcanoes, the Piton de la Fournaise (Peak of Furnace), is one of the most active volcanoes in the world. But scientists noted that the modern-day eruptions of the plume are nothing compared to its past.
A series of lava floods called Deccan Traps smothered 1.5 million square kilometers of land around 65 million years ago for 700,000 years. A team of geophysicists ad seismologists in 2012 set out to map the mantle plume tree by deploying a giant network of seismometers across the vast Indian Ocean floor.
A Titanic Mantle Plume Tree
Wired reported that almost ten years later since they deployed seismometers, the team of geologists and seismologists revealed that the mantle is stranger. In the paper, titled "A Tree of Indo-African Mantle Plumes Imaged by Seismic Tomography" published in Nature Geographic, the team reported that it was a titanic mantle plume tree that rises from the mantle and has branchlike structures that approach the crust where they sprout smaller, vertically rising branches of super hot plumes that underlie known volcanic hot spots.
The discovery of the mantle plume tree nearly coincides with another discovery last November wherein researchers found additional structures in the plumes under Africa. When the two discoveries are combined, researchers suggest that the plumes may have elaborate backstories that have started many years ago.
Study co-author Karin Sigloch said that the core-mantle boundary shows where oceans would most likely open in the future. When that time comes, researchers forecast that land will be obliterated and, in a few tens of millions of years from, South Africa or Earth, in general, will become uninhabitable.
Mantle Plumes Exist Below Tectonic Plates
The theory on tectonic plates explained where volcanoes appear, where the land starts to form, and where ocean basins are carved. However, it failed to explain Hawaii, which is an archipelago of volcanoes.
According to Earth Magazine, Canadian geophysicist John Tuzo Wilson proposed in 1963 that volcanic chains in Hawaii are forged when a tectonic plate continuously drifts over a stationary hot spot in the mantle. This creates a sequence of volcanoes that erupt, grow, and die out as the tectonic plate moves away from the magmatic fuel source.
The journal PNAS also reported that American geophysicist William Jason Morgan proposed in 1971 that hot spots resulted from mantle plumes originated near the Earth's core at depths of more than 1,550 miles (2,500 km).
A few decades later, geophysicists concluded that mantle plumes are around 200 degrees Celsius, which melts their surroundings and create plenty of magma. Wired reported that the mantle plumes also carry mantle materials up to the Earth's surface.
Although no one has seen any mantle plumes yet, they are inferred to exist. Scientists have found evidence of their existence over the years and pointed to seismic waves to validate claims of mantle plumes. Seismometers pick up information on the speed and trajectory of seismic waves as they pass through geologic bodies. They use this data to try and work out the mysteries hiding beneath the Earth's surface.
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