• A 3D model reveals variations in rock strength beneath Marmara Sea
• Stress accumulation points highlight likely sites for future major quakes

An international research team unveiled a three-dimensional model showing how differences in rock rigidity under the Marmara Sea could trigger large future earthquakes along the North Anatolian Fault, according to SciTechDaily.

The findings offer better insight into fault mechanics and support more precise earthquake forecasts for the Istanbul area.

Turkey lies in one of the world’s most earthquake-prone zones, where the Eurasian, African, Arabian, and Anatolian plates interact.

This complex geology has caused a series of devastating quakes historically, notably the 1939 Erzincan earthquake, which killed over 30,000 people.

Since then, researchers have observed a clear pattern of large quakes progressing westward along the North Anatolian Fault.

Many scientists now consider the most likely site for the next major earthquake to be under the Marmara Sea, which has not experienced a large quake in over 250 years, indicating significant stress buildup.

Despite decades of study, the detailed structure of the fault beneath the sea remained unclear, limiting the ability to precisely identify where earthquakes may start or how to mitigate their impact.

The research team, led by Professor Yasuo Ogawa from Japan and Dr. Tülay Kaya-Eken from Boğaziçi University in Turkey, conducted a detailed investigation of the Marmara Sea region.

The results, published in Geology, present the first full 3D model of the fault beneath the sea, offering new insights into the physical processes controlling earthquake formation and location along the fault.

The team used extensive magnetotelluric measurements from previously deployed stations, which detect subtle changes in the Earth’s electric and magnetic fields reflecting deep underground rock properties.

Through a 3D inversion process, they reconstructed the electrical resistivity of rocks down to tens of kilometers beneath the seafloor.

Analysis revealed a complex pattern of high- and low-resistivity zones. Low-resistivity areas, often containing fluids like water, are mechanically weaker, while high-resistivity zones are stronger and more rigid.

Ogawa noted that these differences indicate stress accumulation areas and help understand ongoing fault mechanics.

The results suggest that future major earthquakes may begin at boundaries between weaker and stronger crust sections or along the edges of high-resistivity zones.