New research has unveiled the ancient origins of the East Anatolian fault, a region notorious for a deadly earthquake in February 2023. This fault, which played a significant role in the creation of the deadly quake, actually formed around 5 million years ago due to the relentless pressure exerted by the Eurasian and Arabian plates.
The birth of the East Anatolian fault led to the fracturing of the Earth’s crust from the North Anatolian fault to the Dead Sea fault, effectively detaching the Anatolian plate from the Eurasian plate, marking the emergence of a distinct tectonic plate.
On February 6, a devastating magnitude 7.8 earthquake struck the region, followed by a separate magnitude 7.6 tremor on another fault branching off from the East Anatolian fault, resulting in the tragic loss of over 59,000 lives. While it remains impossible to predict earthquakes with precision, gaining a deeper comprehension of the fault’s nature could provide valuable insights into identifying vulnerable sections of the fault system and the underlying reasons behind their susceptibility to future ruptures. Donna Whitney, the lead author of the study and an earth scientist at the University of Minnesota, emphasized the significance of this understanding.
The research revealed that a portion of the Arabian plate is currently wedged beneath the Anatolian plate. This region, where the edge of the crust is stuck, is in proximity to the fault that triggered the second earthquake near the Syrian-Turkey border. The contrasting strength in the crust created by this additional layer may have contributed to the initiation of the earthquake in that particular location, according to Whitney.
She commented, “We had no idea it was going to have a big earthquake, absolutely not. But it makes sense geologically.”
Whitney and her team of multidisciplinary Earth scientists employed various methods to explore the formation of the Anatolian plate. These methods encompassed seismic surveys, which employ earthquake waves or induced vibrations to visualize subsurface structures, and mineral dating techniques to determine the age of rocks. Because faulting processes enable hot mantle fluids to ascend and heat minerals, effectively resetting their molecular clocks, the researchers used these rejuvenated minerals to ascertain when and where the East Anatolian fault initially cracked.
Whitney elaborated, “We think that about 5 million years ago, that’s when everything connected.”
The formation of this plate is attributed to the gradual collision of the Eurasian and Arabian plates, both pushing against each other. When combined with stretching or extension from the Aegean seafloor to the west, Anatolia underwent a westward shift. Whitney likened this movement to a watermelon seed slipping out from between two fingers, with the Eurasian and Arabian plates representing the fingers and the Anatolian plate symbolizing the seed.
Since the plate’s formation, seismic activity has predominantly centered around the North Anatolian fault and the East Anatolian fault. The latter has frequently experienced moderate-sized earthquakes, with the largest recorded before 2023 being a magnitude 6.8 event in 2020. In 1939, a quake originating from the North Anatolian fault claimed the lives of over 32,000 individuals, and a magnitude 7.6 earthquake in 1999 resulted in the tragic loss of more than 17,000 lives.”
(Note: This is a rewritten version of the original article with added information and paraphrased content to ensure its uniqueness.)