2024-09-05 18:47:28
He Himalayathe Asian mountain range that houses the highest mountains in the world, is the product of the collision of two tectonic plates that are located exactly under the crust of the Tibetan plateau. These are the continental plates india y Eurasian.
In theory, a pair of continental plates that are converging – that is, colliding – should not cause one of them to break into two halves, but instead one to sink beneath the other. However, a recent study has identified that one of the plates beneath the other is actually colliding. Tibet“the roof of the world,” could be breaking in an unusual way.
An unusual fracture in the crust
Tectonic plates can be of two types: continental (thicker and less dense) or oceanic (thinner and denser).
When two different types of plates collide, the oceanic plate slides beneath the continental plate in a process called subduction. However, when two continental plates collide, there is no way of knowing which one will end up beneath the other, since both are of equal density. And that is the complex situation that occurs south of Tibet, where the Himalayan mountain range is located.
Map showing the location of the world’s major tectonic plates. Photo: Storyboard that
Some experts suggested that the Indian plate was subducting beneath the Eurasian plate, while it resisted sinking into the Earth’s mantle. Others argued that the shallowest part of the Indian plate was corrugated like a carpet and that only the deeper debris entered the mantle.
However, now a team of geologists from China and the United States has discovered a third scenario that was not contemplated: in the collision of both plates, The Indian plate is breaking in halfas if it were the lid of a can of fish.
In this sense, it is a horizontal and not a vertical break, as commonly occurs in divergent plates, as is the case of Africa and Iceland. Thus, the most superficial part is supporting Tibet and the deepest part sinks into the mantle, located 33 km deep in the crust of the continents.
The Tibetan Plateau is also called the “roof of the world”. Photo: Wikicommon
The breakup of the Indian plate
The fragmentation of the Indian plate has been discovered after analyzing the journey of seismic waves from 94 seismological stations in Asia and identifying that this structure has, on the one hand, about 200 kilometers deep and on the other hand, just a few 100 km.
“We didn’t know that continents could behave this way, and that’s pretty fundamental for solid Earth science,” said Douwe van Hinsbergen, a geodynamicist at Utrecht University in the Netherlands and one of the authors of the research, in an interview with the prestigious journal Science, which reported on the discovery.
The finding was presented at last year’s conference of the American Geophysical Union in San Francisco last December and was led by institutions from the United States and China.
The Himalayan mountain range is home to some of the highest mountains on Earth, including Everest. Photo: Wikicommon
Increased risk of earthquakes?
According to Simon Klemperer, a geophysicist at Stanford University and one of the study’s authors, the proposed new crustal tear may be influencing earthquake risk in Tibet.
He even points out that a deep rift in the Asian plateau, known as the the Cona-Sangri faultis an indication that the turmoil in the most vulnerable part of the Indian plate could spread to the surface. However, the direct link to the earthquakes remains uncertain, says the expert.
How were the Himalayas formed?
The Himalayas and their highest peaks, such as the monte Everestis the result of a long series of collisions of two large continental blocks: Eurasia and India, which millions of years ago was a large island, surrounded by other smaller ones, according to the popular science blog ‘Hombre Geológico’.
The first collision occurred in the Late Jurassic, 140 million years ago, when an island arc from India collided with southern Eurasia and formed northern Tibet.
The second collision took place in the Early Cretaceous, 100 million years ago, which ended up giving rise to southern Tibet.
The last and final collision occurred in the Eocene, 40 million years ago, when India came from the south and collided with Eurasia, which it continues to push north at a rate of 1 to 2 millimeters per year.
What are the boundaries of tectonic plates?
Depending on the relative movement of the tectonic plates, these can be three:
Divergent boundaries: when two plates are moving away from each other, for example at the Mid-Atlantic Ridge in the Atlantic Ocean.
Convergent boundaries: when two plates are approaching each other, as in the case of the coasts of Peru, where the Nazca and South American plates converge.
Transform boundaries: When two plates slide past each other, no lithosphere is created or destroyed. Occurs on the San Andreas Fault in California, USA.