A huge underground ‘tree’ is carrying magma to the surface of the earth


But as the team looked around the region, the data began to reveal a spectacular view. The African giant blob, 2,900 kilometers below the surface, forms a “trunk” rising from the middle, reaching a depth of 1,500 kilometers. The upper part of the stem, called the casp, appears to have thick branches of hot material growing from its western and eastern ends. They grow diagonally upwards until they reach a depth of 1,000 to 800 km; At this time, the tops of these branches germinate thin stalks growing vertically.

This thin branch has reached the bottom of a hyper-volcanic reunion. About 3,000,000 kilometers northwest, another diagonal branch extends as far as East Africa, a region erupted with volcanoes and which seemed to be the habitat of one or perhaps two mantle plumes in the work of the previous earthquake.

But there was a problem: this structure was difficult to match with the laws of thermodynamics.

Plums, so warm and playful, rise quickly – 10 times the speed of other mantle migrations, including the movement of the plate. “Plums are so fast. You don’t have time to climb on them, “said Goyes.

Tsekhmistrenko, Sigloch, and company agree: Plumes rose straight to the top. The structure of the tree, evidence of a more complex process running in the mantle.

Here’s how they think it works: African blobs – including the trunk and casp – are heated by the core. The eastern and western parts of the Hot Casp, surrounded by a large portion of the relatively cool mantle material, are bright enough. Eventually, an 800-kilometer blob closes from each end; Both grow vertically over millions of years. Eventually, they reach the shallow boundary between the dense lower mantle and the less frequent upper mantle. There, they eventually spread. Several tails sprout from them and rise vertically, creating those narrow towers that are classically known as plums.

Maria Sekhmistrenko (right) and other technicians set up 57 seismometers in the Indian Ocean in October 2012 during a month-long cruise. The seismometers were recovered a year later.Courtesy Guilhem Barroul

Meanwhile, as one of these two sub-blobs rises towards East Africa and one towards the Reunion, the east and west of the Caspian এখন now closer to it তৈরি form two new blobs, rising directly to the top. As they move later and are located at the bottom right and bottom left of the East African and Reunion blobs, respectively, they are like diagonal, intercon connected branches. In reality, these are individual blobs, all rising vertically.

Independent scientists have widely praised the research. Classically, the problem with high-resolution imaging plume structures is the lack of seismic data. Not this time, Reichart said, “because they had this amazing test in the Indian Ocean,” which wrapped itself in the smog gasboard of the earthquake waves.

Combining data from large arrays with additional seismic data sets has been helpful, as it allows the team to accurately solve the entire portion of the mantle from its maximum depth to maximum height. “It’s one step ahead in terms of seismology,” said Carolina Lithgo-Bartelloni, a geophysicist at the University of California, Los Angeles. “In that sense, I think it’s great.”



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