There is rarely a mountain as majestic as the Himalayas, which rise so high into the sky that people feel like a dot standing in front of them. But it is a lesser known fact that the Himalayas are not only scenic but also a field considered important for the study of geology. A 2023 study in this region suggested that the Indian tectonic plate, which covers part of the Himalayan floor, could be splitting in two. The reason for this is that the plates beneath the Himalayas undergo a bizarre process.
The Great Himalaya Range extends in steep, jagged formations and includes hundreds of peaks, with Mount Everest reaching a height of 29,035 feet. It was first sculpted 40-50 million years ago when the Indian plate collided with the Eurasian plate, curving its surface and shaping the world’s tallest mountain. Because both plates had the same thickness, they did not collide with each other, but instead clumped together, creating colossal rock-like structures.
A geologist from Stanford University, Simon L. Klemperer, along with some of his fellow geodynamicists, went hunting for the Himalayan zone in Bhutan. There they examined the levels of helium in the Tibetan springs. Although the Himalayas are a mine for elements like gold and silver, the presence of helium, especially in inappropriate quantities, suggested the possibility of a dormant volcano hidden somewhere beneath.
The research was conducted after keeping two previous theories in mind. One theory was that the Indian plate collided horizontally with the Eurasian plate, while the second theory suggested that the Indian plate subducted beneath the Eurasian plate, melted into magma and spewed helium. The study found that helium levels in southern Tibet were higher than in northern Tibet. This led Klemperer to conclude that the Indian tectonic plate split into two fragments beneath the Tibetan Plateau, in a process known as ‘delamination’.
Klemperer considered both theories and proposed a third theory, saying that the processes mentioned in the first two occurred simultaneously. While the upper part of the Indian plate rubbed with the Eurasian plate, the lower part of the Indian plate diverged into the mantle. The researchers originally presented their findings in December 2023 at the American Geophysical Union conference. “We didn’t know that continents could behave like this and that is quite fundamental for solid earth sciences,” Douwe van Hinsbergen, a geodynamic researcher at Utrecht University, told Science.
To conduct the research, Klemperer used a series of isotope instruments to measure the bubbling of helium in the mountain springs. They collected samples from about 200 sources over a distance of 1,000 kilometers and found the sharp line where mantle rocks connected to the crustal rocks. They discovered a group of three springs where the Indian plate seemed to be peeling away like the two yellow peels of a banana.
The layers of a tectonic plate are designed like a layered cake. The lower layer is dense and thicker than the upper layers. But when two plates collide, there is a possibility that the weaker layers may surrender and begin to break. So before this study, scientists were aware that tectonic plates could break away in this way. But this process was mainly observed on the thick continental plates and simulated in computer models. “This is the first time that… it’s been caught red-handed in a downslope,” Van Hinsbergen said.
This wobbling configuration of the tectonic plates poses a threat to the great mountain range, but also signals the danger of unexpected earthquakes and tremors. While the research uncovered valuable data, the results depicted the contradictory forces of nature dancing with each other.