New research reveals strange blobs beneath the continent Africa is in an unstable condition. This instability causes an eruption volcano large more frequently in the region.
In addition to Africa, researchers also found similar blobs located in the Pacific Ocean. But these blobs are in a more stable condition than the blobs in Africa.
The instability of the African blob has a variety of effects, from major volcanic eruptions to earthquakes.
“This instability can have many implications for surface tectonic activity, as well as earthquakes and supervolcanic eruptions,” said Qian Yuan, a researcher in the geology department at Arizona State University (ASU) who led the research.
Both blobs are located quite deep between the layers of the Earth’s crust. The African blobs are said to be relatively close to the surface compared to the Pacific blobs.
A pair of odd plumes beneath the Pacific and Africa was first discovered in 1980. In scientific terms, ‘superplumes’ are known as large low-shear-velocity provinces (LLSVPs).
The designation means that seismic waves generated by earthquakes pass through this zone, the waves will slow down. This slowdown suggests there is something different about this region of the mantle, such as density, temperature or even both.
Until now scientists weren’t sure why these clumps existed. According to Yuan there are two popular hypotheses explaining this blob.
First, they consist of accumulated crust that has been subducted from the Earth’s surface into regions of the mantle. Another reason is that the clumps formed from the remnants of a sea of magma that may have existed in the lower mantle during Earth’s early history. As this ocean of magma cools and crystallizes, it may leave an area that is denser than the rest.
The current study found Africa’s LLSVP stretches for about 1,000 kilometers with an elevation of 999 kilometers. While the Pacific blobs in total have a height of 700 to 800 kilometers.
Yuan mentions the African blob being much taller than the Pacific blob, most likely making it less dense.
“Because it is less dense, it is not stable,” he said, as quoted by Live Science.
“[Gumpalan Afrika] “It’s very close to the surface, so it’s possible that a large mantle plume could rise from the African plume and could cause more tectonic shifts to the surface and earthquakes and supervolcanic eruptions,” Yuan added.
In laboratory modeling, both the African and Pacific blobs appear to oscillate up and down through the mantle. This research has been published in nature.
Experts hope the findings of these two clumps can help reveal the origin of the creation of the Earth.
(lom / mik)
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