Old structures and substandard construction practices may have contributed to the devastating number of casualties from a violent earthquake in Turkey and Syria, Northeastern experts say.

Residents of southeast Turkey and the war-torn northern Syria were awakened at 4:17 a.m. Monday (local time) by a 7.8 magnitude earthquake, according to the U.S. Geological Survey.

The epicenter of the earthquake was 11.1 miles (17.9 km) deep under the Turkish city of Nurdağı in the Gaziantep province near the junction of the Anatolia, Arabia and Africa tectonic plates, according to USGS.

President Recep Tayyip Erdoğan said about 3,000 buildings collapsed across Turkey after the initial earthquake, killing at least 3,000. More than 1,250 died in Syria, according to the New York Times, and the numbers were expected to rise with rescue operations underway.

Multiple countries committed to send manpower, rescue dogs and aid to Turkey, while Syria territory affected by the earthquake might be hard to access because of the ongoing civil war.

Cyprus, Egypt, Israel and Lebanon also felt the earthquake. Dozens of aftershocks followed, including a 6.7 earthquake 11 minutes later and an unusually powerful 7.5 earthquake nine hours later.

Turkey is prone to seismic activity, says Jerome Hajjar, chair of the civil and environmental engineering department at Northeastern and director of the Laboratory for Structural Testing of Resilient and Sustainable Systems. 

“Earthquakes are extremely hard to predict,” he says. 

There are currently no systems or scientific ways to predict an earthquake and to issue definitive warnings, he says.

However, due to breakthroughs in the late 1970s and 1980s, there’s a better understanding of how structures behave during earthquakes, and design standards for buildings greatly improved, Hajjar says.

“In general, Turkey has very good engineering and engineers,” he says. 

At the same time, after a similar magnitude earthquake in 1999 in Izmit, Turkey, civil engineers discovered that construction practices often didn’t hold to the advanced engineering drawings, Hajjar says.

“It’s too early to tell, but from the photos, certainly, it looks like a number of the tragic collapses were reinforced concrete and masonry structures,” Hajjar says.

Older structures that were built out of lightly reinforced concrete or masonry fold easily, he says, unless they are retrofitted according to modern standards.

Expert in progressive collapse of structures

“If design and construction standards are followed, the probability of collapse is rather small,” says Mehrdad Sasani, professor of civil and environmental engineering, who is an expert in progressive collapse of structures and earthquake engineering.

Modern buildings can be designed to withstand an earthquake, while the damage to the structure is expected, he says.

“If they had designed and more importantly constructed based on the current codes and standards, there would have been a very small percentage of collapsed buildings for this level of earthquake,” Sasani says.

Since the earthquake occurred early in the morning when most people were inside, that increased the number of fatalities. Vertical components of buildings, such as walls and columns failed, and the heavy floors fell on top of each other, stacking like pancakes, Sasani says. 

But he is hopeful that the overall casualties will be on the lower side of what could be expected for such a large earthquake in this area, based on early estimates. 

“Magnitude of the earthquake is just one factor regarding how damaging it is. How populated the area is and how severely the ground is shaken are crucially important,” Sasani says.

He says it would take Turkey up to a couple years to rebuild, while in Syria the damage might be written off in addition to other damages due to the war.

How would a significant earthquake affect the U.S.?

In the U.S., significant seismic activity occurs in the center of the country and on the West Coast. There could be significant earthquakes around Memphis, St. Louis, Hajjar says. 

“Even in the Northeast, there are possibilities for moderate earthquakes,” he says.

American inspections of structures are done very thoroughly, however, often by independent inspectors, to make sure that they hold to engineering intent, he says. 

“That’s a critical step in the process and it doesn’t happen in some other countries,” Hajjar says. 

To prevent the volume of devastation, old buildings can be retrofitted in a number of ways. Steel bracing, concrete frames, enhancement of the connection regions are some of them, Hajjar says.

“There has been a lot of progress since the 1970s and ‘80s on earthquake engineering worldwide both in terms of developing new structural systems that are much more resilient to earthquakes as well as retrofitting older structures,” Hajjar says.

California has been conducting a significant retrofitting program, he says, for schools, hospitals, bridges and other critical facilities for several years now.

“The structural steel systems that are in the current national design specifications are excellent for seismic engineering,” Hajjar says.

Owners of the buildings constructed before the late 1990s should consider the status of their structures, he says, and have them inspected for extreme events.

In other countries around the world it can be very difficult to get funding for reinforcement projects, Hajjar says.

Rebuilding communities should be worldwide effort

“Unfortunately, poorer communities that suffer such devastations often are left to mend for themselves, and they continue with limited resources building structures vulnerable to earthquake-induced damages,” says Mishac Yegian, distinguished professor of civil and environmental engineering at Northeastern.

In his opinion, there should be a prudent worldwide-effort to reduce the number of existing inventories of vulnerable buildings and other types of structures that should be strengthened or replaced with new structures designed following modern regional seismic codes.

The Feb. 6 earthquake occurred along the East Anatolian fault that had not ruptured for a few hundred years, Yegian says. 

The country is mostly located on the Anatolia tectonic plate, which is defined by two faults, North Anatolian and East Anatolian, and is being pushed by the Arabian plate, he says.

“What is surprising is that the two earthquakes caused progressive ruptures along a large segment of the East Anatolian Fault,” he says. “This is evidence that the stresses along the fault and its tributaries had been locked for a long time and the two events are.”

The aftershock pattern also implies that the ruptures of the faults were initiated from the northern portions and progressed towards the southern portion of the fault, he says. This may be an explanation why the earthquake ground motions were felt all the way to Syria, Cyprus, Egypt, Lebanon, and Israel and not in the northern regions of the fault. 

Alena Kuzub is a Northeastern Global News reporter. Email her at a.kuzub@northeastern.edu. Follow her on Twitter @AlenaKuzub.