Earth crust consists of six major tectonic plates and nearly twenty other minor plates. One of these major tectonic plates is India-Australia-Capricorn tectonic plate. But this plate is splitting into pieces, study reveals.

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AurĂ©lie Coudurier‐Curveur from Earth Observatory of Singapore, Nanyang Technological University, and other co-researchers have conducted the study. The research paper is entitled as ‘Is There a Nascent Plate Boundary in the Northern Indian Ocean?’, published in a journal named Geophysical Research Letters.

Findings of the study

If we consider the time geologically, then the splitting progress of the said tectonic plate is quite faster. But from basic view point, it is increasing at a snail's pace, that is nearly 0.06 inch or 1.7 millimetres per year. Thenceforth,  through this way, after a million year the splitted parts would be almost 1 mile or 1.7 km apart from each other than present location.

AurĂ©lie Coudurier‐Curveur, the lead author of the paper, stated that,
It is not a structure that is moving quickly, but it is still significant as compared to other plate boundaries.

Researchers mentioned the plate boundary as ‘nascent plate boundary’. In the Wharton Basin area beneath the Indian Ocean, two earthquakes of high magnitude (8.6 and 8.2 in Richter scale) had been detected, but both was originated from a wired spot – middle of the plate, rather than from the convergent or divergent boundary area as usually happens. This is quite rare instance.

Tectonic_Plate_Under_Indian_Ocean_is_Breaking_into_Pieces
Tectonic setting of the fracture zone in the Indian Ocean Basin | Image Courtesy : Geophysical Research Letters

Not only the earthquakes, but also some other geological forces took part in the the deformation process in the Wharton Basin area, which leads to the splitting of the plate.

According to the study, there exists a fracture zone, apart from the plate boundary area, from where the earthquake were originated. Analysing the data obtained, they found a depression developed at the strike-slip fault area. Along this fault the two blocks slide horizontally to each other through a trans-current movement. This was the reason behind the origination of that earthquakes.

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The mapped fracture zone reveals that the depth of the depression formed in that area, is high (almost 394 feet, or 120 metres deep) in the southern part, rather than the northern part where it is very much shallower (about 16 feet or 5 metres).

Coudurier‐Curveur explained that,
It may mean that, this strike-slip fault is more localized at its southern boundary.


How did the fault develop?

The said fracture zone depicts the the weakness in the oceanic crust. This did not develop due to the earthquakes. But some passive cracks formed partly and new oceanic crust developed from mid-ocean ridges, and finally cracked because of the curvature of the Earth surface.

The oceanic crust that is under research is not a uniform one, rather unification of three tectonic plates –researchers mentioned. As these plates are moving at different paces, the fracture zone is emerging as a new plate boundary which is causing the plate’s split into two new pieces.

Researchers have presumed that another earthquake would not going to happen in the next 20,000 years from that spot, because the splitting is progressing at a snail's pace, and accordingly the whole splitting process might come to an end in coming tens of millions of years.

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