The India – Australia – Capricorn tectonic plate is separating at a rate of about 1.7 mm a year.
In a million years, the distance between the two halves of this tectonic plate will be 1.7 kilometers farther than it is today, according to Aurélie Coudurier-Curveur, a graduate student in marine geosciences at the Paris Institute of Earth Physics. . Coudurier-Curveur and colleagues published the study results May 11 in the journal Geophysical Research Letters.
The Wharton Basin was the site of two 2012 earthquakes (Image: Live Science).
Compared to this plate tectonics, the Middle East Sea Chat fault moves at twice as fast, about 0.4cm a year, while the San Andreas fault in California moves 10 times faster, at 1.8cm a year. The Indo-Australian-Capricorn tectonic plate split so slowly and so deeply that researchers would have missed the tectonic plate boundary if there was no evidence that two powerful earthquakes originated at an odd spot in India. Do Duong.
On April 11, 2012, an earthquake of magnitude 8.6 and 8.2 occurred in the Pacific Ocean, near Indonesia. The two earthquakes do not occur along the subduction zone, where one tectonic plate slides under the other. Instead, they originate in the middle of the tectonic plate. These earthquakes reveal that there is some deformation underground in an area called the Wharton Basin.
The separation process of the India – Australia – Capricorn tectonic plate occurs underwater at a very slow speed, making it difficult to detect. (Photo: EOS).
The team looked at a particular fault zone in the Wharton Basin , where the earthquake originated. Two sets of data in this area, collected by scientists on board the research vessel in 2015 and 2016, show the topography of the fault area. By recording the time it took for the sound waves to return from the seabed and bedrock, the research vessel was able to map the topography of the basin.
When Coudurier-Curveur and colleagues looked at the two datasets, they found that the evidence for the stretching was the subsidence that formed in the transverse slip fault zone. The most famous horizontal slip fault is probably the San Andreas fault. This type of fault causes earthquakes when two plates of the Earth’s crust slide horizontally past each other. The team found 62 basins along the mapped fault zone, spanning nearly 350 kilometers. Some basins are huge, 8km long and 3km wide.
In addition, the depressions are deeper in the south (120 m) and shallower in the north (5 m). According to Coudurier-Curveur, this means that the transverse fault is concentrated on the southern boundary, at least for the time being. The basins began to form about 2.3 million years ago, after the fault formed along the 2012 epicenter. As different parts of the Indo-Australian-Capricorn plate moved at different speeds, the fault zone This fault is becoming the new boundary for the tectonic plate to split.