Tectonic plates beneath southeastern Iran are tearing apart as they grind against each other, according to a study published in Nature Geoscience. Researchers from the Chinese Academy of Sciences found extensive evidence of two giant fractures in the Arabian Plate, ScienceAlert reported. The movement offers geologists a rare look at how oceans disappear and continents collide.
The Arabian Plate consists of two distinct rock types behaving differently under pressure. An oceanic slab formed from the ancient Neo-Tethys Ocean consists of heavier, thinner basalt rock being pushed beneath a neighboring plate. Meanwhile, continental rock to the west is thicker and less dense, resisting subduction and forming mountain ranges when it meets resistance. This mismatch creates severe stress along the boundary.
Seismic Stations Map Deep Underground Fractures
To measure geological activity deep underground, researchers deployed a network of 69 seismic monitoring stations. These instruments recorded vibrations from distant earthquakes between March 2017 and September 2018. Because seismic waves change speed based on rock temperature and density, the recordings revealed the exact structure of the subterranean disruption.
The data exposed two distinct tears in the plate. One horizontal tear sits where the Zagros collision zone meets the Makran subduction zone. A smaller vertical tear rests closer to the surface near the Makran Trench. The oceanic lithosphere in the Makran zone has subducted to depths of at least 450 kilometers, while the continental lithosphere in the Zagros zone has subducted no deeper than 300 kilometers.
Arabian Plate Tears Expected to Merge Over Time
Computer models indicate that the two ruptures have been progressing for several million years. As the continental plate advances northward, the intervening boundary segment is progressively consumed. Researchers stated in their published paper that this progressive linkage will eventually drive the coalescence of the two tears.
Hot magma is already filling some of the gaps created by the ruptures. While humans will likely have left planet Earth before the two tears finally meet, the active faults provide geologists with a snapshot of the Wilson Cycle in real time. The transition from oceanic subduction to continental collision remains a key stage in how oceans form, expand, and eventually vanish.
Scientists track seismic waves using monitoring stations
How did researchers detect the tears underground?
Scientists used a network of 69 seismic monitoring stations operating between March 2017 and September 2018. The stations measured how vibrations from distant earthquakes changed speed as they passed through rocks of varying temperatures and densities.
How deep have the tectonic plates subducted?
In the Makran subduction zone, the oceanic lithosphere has subducted to depths of at least 450 kilometers. In the Zagros collision zone to the west, the continental lithosphere has subducted no deeper than 300 kilometers.
Where was the research published?
The findings were detailed in a study published in the journal Nature Geoscience by a research team primarily led by scientists from the Chinese Academy of Sciences.
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