Rarely are there any mountains so majestic as the Himalayas that rise so high in the sky that people feel like a point standing before them. But it is a lesser known fact that the Himalayas are not only scenic but also an area considered important for the study of geology. A 2023 study in this region proposed that the Indian tectonic plate, which forms the last part of the Himalayas, could split in two. The reason, the plates under the Himalayas are going through a strange process.
Stretching high in steep and craggy formations, the Great Himalayan Range includes hundreds of peaks, with Mount Everest reaching a height of 29,035 feet. It was first carved 40-50 million years ago when the Indian Plate collided with the Eurasian Plate, bending the surface and shaping the world’s highest mountain. Since both plates were the same thickness, they did not collide with each other, but rather, piled up on each other and gave birth to colossal rock structures.
A geologist from Stanford University, Simon L Klemperer, went on a hunt in the Himalayan area of Bhutan with some of his geodynamist colleagues. There, they investigated the levels of helium present in Tibetan springs. Although the Himalayas are a mine for elements like gold and silver, the presence of helium, especially in inappropriate amounts, suggested the possibility that there was a dormant volcano hidden somewhere below.
The study was conducted keeping two previous theories in mind. One theory was that the Indian Plate was colliding horizontally with the Eurasian Plate, while the second theory suggested that the Indian Plate was subducting beneath the Eurasian Plate, melting into magma and releasing helium. The study found that helium levels were higher in southern Tibet compared to northern Tibet. With this, Klemperer concluded that the Indian tectonic plate was splitting into two fragments beneath the Tibetan Plateau, in a process known as “break-up”.
Klemperer examined both theories and proposed a third theory, where he said that the processes mentioned in the first two were occurring simultaneously. While the upper part of the Indian Plate was rubbing against the Eurasian Plate, the lower part of the Indian Plate was drifting (subducting) into the mantle. The researchers first presented their findings in December 2023 at the American Geophysical Union conference. “We didn’t know that continents could behave this way and this is, for solid earth science, quite fundamental,” Douwe van Hinsbergen, a geodynamist from Utrecht University, told Science.
To carry out the study, Klemperer used a series of isotope instruments to measure helium bubbling in mountain springs. They collected samples from about 200 wells over 621 miles and found the bleak line where mantle rocks meet crustal rocks. They discovered a group of three springs where the Indian Plate appeared to be peeling off like the two yellow peels of a banana.
The layers of a tectonic plate are designed like a layer cake. The lowermost layer is dense and thicker than the upper layers. But when two plates collide, there is a chance that the weaker layers will give way and begin to break. So, before this research, scientists were aware that tectonic plates could peel off like this. But this process was mostly observed in thick continental plates and simulated in computer models, “This is the first time that … it has been caught red-handed in a subducting plate,” van Hinsbergen said.
This wobbly configuration of tectonic plates poses a threat to the great mountain range, while also suggesting the risk of earthquakes and sudden shakes. Although the study revealed valuable data, the results depicted contradictory forces of nature dancing with each other.
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