By Amar Rahman, Ph.D., Principal Risk Engineer, Zurich Insurance
The quake had special significance for me personally, as my hometown—Khanaqin—lies on the Iraqi side of the border, just 50 km southwest of the epicenter.
Extensive damage and causalities (approximately 400 deaths and 7,000 injured to date) have been reported from the Iranian side of the border, probably reflecting the higher population density, as well as the higher level of preparedness of local authorities to natural catastrophe events.
Reports I’ve received from relatives on the Iraqi side report the total devastation of the city of Derbandikhan (population 340,000) in Sulaymaniya province. The city lies 25 km west of the epicenter and is the largest city on the Iraqi side of the border closest to the event. The condition of a major dam near the city of Derbendikhan is unknown. The dam was built in the late 1950‘s and already underwent a major repair in the late 1990‘s after extensive leakage of the spillway gates. It is highly likely that the dam has sustained some level of damage. Unfortunately, Iraqi expertise regarding damage inspection is low.
While the Iranian seismic design code is more developed than its Iraqi counterpart, residential buildings on both sides of the border are typically not ‘engineered,’ meaning that no engineer participated in their design and construction. Moment-resistant reinforced concrete frame construction, with unreinforced masonry walls, is common. I would expect onsite damage assessment to take quite a bit of time, due to the paucity of seismic specialists.
Damage reports from Khanaqin (about 40 km south of epicenter) refers mostly to damage to contents rather than the building frame, we hope this is accurate. In the other direction, in Erbil (210 km northwest of the epicenter), shaking of single- and double-story residential buildings of the same construction type that I previously described) was widely reported. Parked cars were severely shaken, but no structural damage has been reported there to date. Damage to contents is also very low.
What I also found interesting is a report from Iraq the morning after the event—supposedly from a local seismologist—who claimed that the event wasn’t tectonic but due to Iranian nuclear tests (“fake news”). But the 10 km depth and thrust focal mechanism render such an inference extremely unlikely, as these are typical of the region, whereas nuclear tests are shallow, and the focal mechanisms are implosive or explosive.
(The contribution reflects the opinion only of the author).