Professor Naci Görür, a geophysics expert, has described a stretch of Istanbul, Turkey’s most populated city, as sitting "within the bounds of hell" as he warned about a potential future earthquake.

The city that last suffered heavy damage from earthquakes in 1999 is on edge in light of the repeated warnings by experts about the anticipated "big one," an earthquake with a magnitude of 7.0 or higher.

Görür says the region stretching from the Golden Horn to the far-flung Silivri district on the European side of the city would sustain the most damage from tremors originating from a fault line some 9 kilometers (5.5 miles) off the coast of the Marmara Sea.

He points to potential fallout along a line extending 20 kilometers from the south to the north.

His comments came on Friday at a symposium on earthquake preparedness held in Avcılar, a district on the European side where the 1999 earthquake inflicted heavy casualties.

The epicenter of the 1999 earthquake was off the coast of Gölcük, a town east of Istanbul, originating some 80 kilometers away from Avcılar. Yet, the old buildings in the district succumbed to damage. Görür said it was not a coincidence, explaining that the geological structure of the region is susceptible to such disasters. "Most of the European side is under threat. Avcılar and (neighboring) Küçükçekmece districts are rich in streams and valleys and those only aggravate the impact of the earthquake. Avcılar sits on a ground composed of clay and limestone. In other words, the ground material is not very enduring," he told the event.

Görür says there are no active fault lines on land, however, activity along the sea fault lines could trigger the inactive ones on land as well. "An earthquake at a magnitude of 7.2, for instance, can trigger landslides in an area from Küçükçekmece to Büyükçekmece," he warned. The expert highlighted that an earthquake with a magnitude of 7.0 would inflict the equivalent amount of damage as 1.8 million tons of explosives. "Along with collapses, such an earthquake would cripple infrastructure and cause fires. So, it is not sufficient to simply rebuild sturdy buildings as protection. Authorities should allocate a budget for (better infrastructure) as well," he said.