February 6, 2023

expert reaction to the earthquake near the Turkey/Syria border

A 7.8 magnitude earthquake struck near the Turkey-Syria border in the early hours of Monday 6 February 2023.

Ziggy Lubkowski, Associate Director, Seismic Design at Arup, said:

On seismic activity in region:

“The region sits on a major plate boundary and near the intersection with a second plate boundary.  It is therefore a region of high seismic hazard. It isn’t the first earthquake of a similar magnitude to occur in the region – in 1138 the city of Aleppo, around 100km south of Gaziantep, was destroyed by an earthquake which is likely to have had a similar magnitude. The magnitude scale we use is a measure of energy released. It is based on a logarithmic scale, so one order of magnitude releases 30 times more energy, i.e. an 8 releases 30 times more energy than a magnitude 7 earthquake. 

“Most earthquakes of this magnitude will generate significant aftershocks, this is not uncommon. We would expect the aftershocks to continue for several weeks and potentially months.”

On design codes:

“Earthquake design codes were first published in Turkey around 1975. A step change in the building codes followed the 1999 Kocaeli earthquake. Building codes are now regularly updated and are consistent with the best European, Japanese or US codes.

“Design practices can be the best in the world to withstand an earthquake, but it’s important to note that this must be matched by good construction practices which align with that design, in addition to supervision of that process to ensure standards are met. For the system to perform adequately good design, construction and supervision practices must all be adhered to.”

On building performance:

“Life safety codes are the minimum requirement when it comes to seismic performance – with buildings designed to be life safe to protect those inside, ahead of considering how to prevent irreparable damage to the structure. 

“Buildings are designed to absorb the energy of the earthquake, limiting cracking so the building holds together and remains robust.

“Important response structures, such as hospitals, fire stations and power plants need to remain operational in the wake of an earthquake.  

“Building performance in this earthquake has not yet been analysed – this process will occur in the coming months as engineers examine the effects of the earthquake to determine how it can be learnt from. However, it is likely that older buildings performed worse than newer ones.”

Prof Bruce Malamud, Professor of Natural and Environmental Hazards at King’s College London, said:

On a suggested link with the High Frequency Active Auroral Research Program (HAARP):

“There are no credible or possible linkages between the high-frequency active auroral research programme (HAARP) and the causation of earthquakes of any magnitude, including the most recent tragic 6 February 2023 earthquake in Turkey. HAARP is a research programme devoted to studying the ionosphere, which is part of the Earth’s upper atmosphere (about 48 to 965 km above sea level). There is no known physical mechanism possible where the HAARP could have caused the earthquakes, and any claims of such linkages fall well outside the scope of the natural sciences. Any advocates of such linkages, such as conspiracy theorists, should be ignored and their claims treated as false news.”

Prof Ian Main, Professor of Seismology and Rock Physics, University of Edinburgh, said:

“The plates in the plate tectonic system are moving all the time at a constant rate, not just when there is an earthquake.  We know the interior of the Anatolian plate is moving westwards at around 22mm per year, every year, as imaged by satellites.  However, at the plate boundaries the fault is stuck in between earthquakes, so the motion drags behind the bulk movement of the plate, and the ground around the fault bends to accommodate the drag.  This builds up pent up elastic energy in the crust surrounding the fault, in this case near or on the East Anatolian fault. When the earthquake happens the slip on the fault catches up with the movement of the rest of the plate, in this case some two centuries of accumulated slip (on the order of a few metres), and the pent up energy is released, causing the radiated waves and resulting in strong ground motion. So the Anatolian plate moved a large amount only near at its boundary with the East Anatolian fault. The whole of Turkey did not move.”

Prof Ilan Kelman, Professor of Disasters and Health, University College London, said:

“The window for post-earthquake search-and-rescue is rapidly closing. Typically, few survivors are pulled out after 72 hours—yet every life saved is essential and some people are extricated after many days.

“Time is always the enemy, as seen in Turkey and Syria. People die due to immediate medical needs such as bleeding to death or succumbing to crush injuries; due to aftershocks that collapse precarious structures with people underneath; and due to the weather which has dropped below freezing at night and which has been cold during the day, so people die through hypothermia. Many die from lacking food and water while awaiting rescue.

“Local, national, and international rescuers are risking their own lives to save others. Every success must be celebrated with huge gratitude, while remembering that prevention is far better than responding afterwards.”

Prof Bruce Malamud, Professor of Natural and Environmental Hazards at King’s College London, said:

“As a result of the 6 February 2023 Turkey earthquake, the hazard relief agencies and managers will also be conscious of other natural hazards and multi-hazard cascades. The seismic activity will likely trigger hundreds if not thousands of landslides in the hours to days after the earthquake and subsequent aftershocks. Hazard managers will also be faced with the relocation of large numbers of people, and they will need to be aware of where they move these people, not moving them into another hazard-prone area, such as to floods. This has occurred in the past in Asia, where as a result of an earthquake, large numbers of people were removed to a flood plain, which months later flooded, resulting in further losses.“

Prof Joanna Faure Walker, Head of the UCL Institute for Risk and Disaster Reduction, said:

“It is commendable that the Turkish Government did put out an appeal for international assistance as often a mistake is to not recognise the need early enough and local people and communities can suffer even more as a result.

“The East Anatolian System is a known area of potential earthquake activity and earthquakes this size are expected – however we are not yet able to say exactly when or where so planning on short term is a challenge.

“Stress changes along the fault system can trigger additional events so vigilance should be observed, especially in buildings lacking seismic resistance and anywhere that has already suffered possible damage from previous shaking as there may be hidden weaknesses in buildings making them more susceptible in subsequent shaking.”

Dr Henry Bang, Geologist, Disaster Management Expert and Researcher at the Bournemouth University Disaster Management Centre, said:

How is the really strong mag 7.5 second shock related to the first mag 7.8?  It may not technically be an aftershock but presumably it was triggered by the first quake?

“Aftershocks are common features of earthquakes and should be expected especially after major earthquakes. Aftershocks are usually caused by adjustments on the displaced fault surfaces that caused the major earthquake as the strain from the major earthquake tries to dissipate and the rocks try to fall back into place. Initial earthquakes can also trigger aftershocks on other minor or major faultiness in the vicinity of the which were at an advanced stage of displacement. They usually occur in the same area after the first, main or major earthquake and can happen minutes, hours or days following the main earthquake. Historically, the magnitude of aftershocks has been much smaller than that of a major earthquake, but it could be larger. For instance, one of the highest aftershocks ever recorded was the 2004 Sumatra earthquake (Magnitude of 9.3) which produced an aftershock of mag 8.7.

“Looking at the position of the first and second major earthquakes that hit the region, and the timeline between them, I reckon the second magnitude 7.5 earthquakes was triggered by the first magnitude 7.8 earthquake with just a 0.3 magnitude deficit. Hence it could be considered an aftershock albeit the magnitude is high. Considering the aftershock occurred more than 60 miles away from the epicentre of the first major earthquake which is located near the city of Gaziantep, it likely occurred on a different fault line from the first major earthquake. Arguably, this second mega-earthquake was triggered by the first. It is likely that the rocks along the extensive strike-slip faults in this region could have been under very intensive forces that placed them at an advanced stage of potential displacement. The first shock expedited the displacement process, resulting in a 7.5-magnitude earthquake. It should be noted, however, that more than 120 aftershocks have also been recorded after the first major 6th February earthquake in Turkey and Syria.”

What does the impact tell you about building design in the region?  Are you surprised at the level of damage or loss of life?

“Earthquakes of magnitudes 7 and above on the Richter Scale are major earthquakes that produce serious damage to buildings and can cause landslides depending on the geology and geomorphology of the region. I am not surprised by the damage to thousands of buildings in the area near Gaziantep, which are responsible for the very high death toll. Apart from the high-magnitude 7.8 earthquake and its aftershock that hit the region, other factors can also be responsible for the extensive damage to buildings.

“First, the distance to the epicentre or the point where the earthquake originated, can be a factor. The epicentre of the earthquake is near the city of Gaziantep. That is why the city has suffered the most intensive damage to its infrastructure since the earthquake waves take a relatively short distance to reach the built area.

“Second, the shallow depth of the earthquake epicentre, which has been reported to be around 17.9 km is another key factor. The reach of the seismic waves originating from shallow depths of less than 60 Km is usually far. In this earthquake,  seven provinces in Turkey and a huge area of Northern Syria have been affected.

“Third, earthquake triggers at show depths usually produce seismic waves that travel with high amplitudes, which are most destructive because of the horizontal movement of the seismic waves through the ground, resulting in more intensive shaking. The amplitude of the waves reduces with distance from the epicentre. That explains why according to my analysis, the most damaged areas in this earthquake are those closest to the epicentre.

“Fourth, the strength of the building or structural design of infrastructure is another key factor responsible for the intensity of damage incurred. Looking at some of the pictures of the damaged buildings, it is evident that most of them were not designed to withstand very strong earthquakes. Some buildings have simply collapsed to the ground while many storey buildings collapsed like a pack of cards. This shows that most of the buildings did not have the relevant features to provide stability during an earthquake. Those whose walls have crumbled to the ground are probably very old buildings that were built with relatively weaker building materials. The storey buildings that have collapsed like a pack of cards were probably not built with earthquake-resistant design features. Taking into cognisance that the region sits in a tectonically active area, it is important that building codes for seismically active regions be introduced and enforced so that all the physical infrastructure can be retrofitted for seismically active regions. This would reduce the risk of destruction, death or injury because most deaths result from the collapse of buildings during earthquakes.

“The time of occurrence of the earthquake is responsible for the high death toll which is likely to exceed 3,000. The earthquake happened in the early hours of the morning when most people were at home, sleeping. This puts more people at risk of the collapse of buildings and gave them less time to react since they were asleep. Had the earthquake occurred in the afternoon, fewer people would have been at home, or probably in buildings. This would have resulted in lesser deaths, but the damage, to infrastructure, nevertheless, would be the same.

“The above explanations indicate that a combination of factors has resulted in the devastating earthquake in Turkey and Syria.”

Does the geology of southern Turkey make it particularly prone to aftershocks and secondary quakes, compared with other earthquake-prone regions such as the Pacific Coast of North America?

“As highlighted before, earthquakes are caused by displacements on faults along plate boundaries due to excessive forces (stress and strain) in the earth’s crust. Plate boundaries are highly susceptible to earth movements leading to earthquakes. The affected area (Southern Turkey and North Syria) has a complex tectonic configuration since it is located close to three plate boundaries or extensive fault zones. These are the boundaries between the Eurasian Plate, African Plate, Arabian Plate and Anatolian Plate. Along these extensive faults, the plates can either exhibit vertical movement or horizontal movement. The vertical movement can occur either when the plates are moving towards each other  (Convergent Plate Boundaries) which results in one plate being forced under the other or when two plates move away from each other (Divergent Plate Boundaries). The horizontal movement will occur when the faults slide horizontally against each other (Strike-Slip Faults).

“Rarely would you find both vertical and horizontal movements, but when they do occur, the magnitude is usually greater because both displacements have the tendency to shake the earth more. While geologists/seismologists are still to accurately determine the actual origin of the 6th February Earthquake in Turkey and Syria, it is conceivable that the complex geology and neotectonics in the region are to blame.

“The tectonics close to where the earthquakes and aftershocks occurred has these characteristics. Indeed, the Southern part of Turkey and the Northwestern part of Syria where the earthquake occurred sits close to two major Plates (the African Plate and Eurasian Plate) and two minor Plates (the Arabian Plate and the Anatolian Plate). These plate boundaries are exhibiting both horizontal and vertical movements. There is a convergent plate boundary where the African Plate to the South is sliding beneath the Anatolian Plate to the North (vertical movement) and at the same time, there are two horizontal movements. One between the North Anatolian Plate to the North and the Southern Eurasian Plate and the other between the South-eastern Anatolian Plate and the Arabian Plate. Any earth disturbances involving these movements are likely to result in major earthquakes in the region. Preliminary suggestions are indicating movement along the strike ship faults, but a combination of both movements could be responsible for the high-magnitude earthquakes.

“This incident serves as a reminder of the region’s high physical vulnerability to earthquakes. The proximity of Syria and Turkey to both Convergent and Strike-Slip boundaries means earthquakes shall happen regularly and this reality needs to be inculcated into the disaster management frameworks of both countries. Learning from this experience, a priority should be to retrofit existing buildings in the region to be able to withstand earthquakes.”

Prof Samer Bagaeen, expert in Planning & Resilient Systems from the University of Kent’s School of Architecture & Planning, said:

“This disaster shown how vulnerable communities end up taking the brunt of multiple stresses and shocks that affect their neighbourhoods. It also shows the critical importance of precovery in addition to recovery, i.e. building capacity and resilience to compounded shocks before they hit in addition to an effective recovery effort after they hit.

“The impact of the earthquake shows the importance of whole society resilience that incorporates the physical infrastructure, design coding and standards, social resilience, and the resilience of critical care and emergency sectors. It is no good to anyone if a hospital is built to high standards for earthquake resilience if the roads leading to it are not.

“Understanding and embedding this whole society mission, which explores connections across and between systems such as climate action, war and conflict, migration and pressures on city infrastructure such as housing and emergency services, is an essential part of architecture and urban planning.”

Prof Mark Allen, Head of Earth Sciences at Durham University, said:

1. How is the really strong mag 7.5 second shock is related to the first mag 7.8? It may not technically be an aftershock but presumably it was triggered by the first quake?

“It looks like the M 7.5 event is on a different fault to the first – the Sürgü Fault, but close enough in time and space to the first event that the second event seems to have been triggered by the first. Earthquakes can transfer stress on to nearby faults, causing them to rupture in new earthquakes. This is usually along the same fault system, but can affect faults nearby – and that’s what seems to have happened in Turkey. It now looks like there are aftershocks to this second major earthquake.”

3. Does the geology of southern Turkey make it particularly prone to aftershocks and secondary quakes, compared with other earthquake-prone regions such as the Pacific Coast of north America?

“I don’t think southern Turkey is particularly prone to aftershocks compared to other tectonically active regions; there are many active faults in SE Turkey and adjacent areas, because the area is at an active plate boundary where the Arabian plate collides with Eurasia and the Anatolian “microplate”. Much of Turkey is within the Anatolian microplate, and is being squeezed out westwards between the East Anatolian Fault (which ruptured today in the M 7.8 event) and the North Anatolian Fault – like a pip between your fingers.”

Prof Jeffrey Kargel, Planetary Science Institute, Tucson, Arizona, said:

“The faults in this area of Turkey involve a sideways slipping, like that along the infamous San Andreas fault in southern California, versus the more direct tectonic plate convergence-driven thrust faulting that is common in areas like Nepal. The common feature of all high-magnitude earthquakes is the abrupt motion of the crust—driven by deep convective motions in the mantle– and the generation of powerful seismic waves that radiate away and shake up the surface.

“The earthquakes in Turkey caused tremendous damage to structures and attendant loss of life. We have seen similar damages of high buildings in other earthquakes. Notable was the collapse of the Dharahara Tower in Kathmandu during the M7.8 earthquake in 2015. That tower had been destroyed by prior earthquakes and then was rebuilt and redestroyed. The cause in that repeated collapse may have been resonant motions. The same could have been involved in the collapses of high-rise buildings in Turkey.

“Another common cause of such horrific building collapses involves liquefaction of over-saturated, poorly consolidated fine-grained soils, like in the 1985 Mexico City and 1995 Kobe earthquakes. Another mechanism includes topographic amplification of seismic wavefields, such as occurred during the 2015 Gorkha earthquake in Nepal. The most destructive cluster of landslides during the 2015 earthquake in Nepal was a disaster within a disaster, killing about 300 people among the more than 9,000 killed in the earthquake overall.

“It is too early to say whether resonant vibrations, soil liquefaction, or topographic amplification may have caused specific buildings to collapse in Turkey. In each of these possible mechanisms, different specific approaches to future construction can be considered, whether that consist of not building in certain areas, or rebuilding with a different architecture. For now, the focus is on offering help in ways that different nations and response agencies, scientists and engineers are able to provide.”

Dr Catherine Mottram, Senior Lecturer in Structural Geology and Tectonics at the University of Portsmouth, said:

1. How is the really strong mag 7.5 second shock is related to the first mag 7.8? It may not technically be an aftershock but presumably it was triggered by the first quake?

“Earthquakes occur when locked portions of faults suddenly ‘break’, resulting in rocks moving rapidly during catastrophic failure events. Aftershocks are usually lower magnitude earthquakes that happen as the crust settles and recovers in the new position. There is the potential that the 7.5 magnitude shock was related to a second period of movement along a different depth or along strike location on the fault, or on a different fault strand. Geophysicists will be able to reconstruct exactly where movement occurred along the fault by reconstructing data collected by seismometers in the region, so more information should come out in the coming days and weeks about exactly what happened.”

2. What does the impact tell you about building design in the region? Are you surprised at the level of damage or loss of life?

“This is a very seismically active area so earthquakes should be expected and therefore I expect that buildings should be designed to withstand earthquakes. I expect that it was mainly older buildings and those built in less wealthy areas where most damage occurred.”

3. Does the geology of southern Turkey make it particularly prone to aftershocks and secondary quakes, compared with other earthquake-prone regions such as the Pacific Coast of north America

“The earthquake likely occurred on either the East Anatolian Fault or Dead Sea Transform, both of these are strike-slip faults, so a very similar geological setting to the San Andreas Fault in North America. The East Anatolian Fault is also a plate boundary between the broadly northward moving Arabian plate and the westward moving Anatolian plate. The Anatolian plate is very seismically active and is bordered by two strike-slip faults, the North and East Anatolian faults. There is also volcanic activity and other modern geological hazards associated with the boundaries.”

Prof David Rothery, Professor of Planetary Geosciences at The Open University, said:

1. How is the really strong mag 7.5 second shock is related to the first mag 7.8? It may not technically be an aftershock but presumably it was triggered by the first quake?
“It is an aftershock. If it had been bigger than the initial mag 7.8 event, we would have redesignated that M7.8 event as a foreshock.
“The M7.5 almost certainly would not have happened today if the M7.8 hadn’t happened – so they are related.
“Here is a pic from Latest Earthquakes (usgs.gov): https://earthquake.usgs.gov/earthquakes/map/?extent=33.18354,29.11377&extent=40.88029,46.69189&baseLayer=terrain. It is timed at 13:50 GMT today. The 2 red symbols are quakes in the previous hour. The blue one is the M7.5 aftershock, which is in blue because I selected it. The M7.8 original is the biggest orange circle most hidden behind more recent orange symbols.
“The East Anatolian Fault is picked out be the SW-NE line of epicentres from Antioch near the Med towards Elazig. This is about half the length of the fault. The continuation NE through and beyond Elazig has not experienced seismicity today. This fault marks where Anatolian Turkey is slipped leftwards relative to the Arabian plate (whose N edge is Syria and southernmost Turkey).
“There is probably another fault becoming active that runs E-W along the Taurus Mountains from near the M7.5 event (not a newly created fault, almost certainly one that has moved in the past). This sort of stress transfer is not uncommon after a major earthquake. I would not expect it to spread much further (maybe 100 km at most) nor to last more than a few days.”

2. What does the impact tell you about building design in the region? Are you surprised at the level of damage or loss of life?
“Given the number of collapsed budlings, I am not surprised by the loss of life. Questions will have to be asked about why most withstood the shaking but some apparently similar collapsed completely. It is possible that building codes intended to give structures earthquake resilience were not adequately complied with.”

3. Does the geology of southern Turkey make it particularly prone to aftershocks and secondary quakes, compared with other earthquake-prone regions such as the Pacific Coast of north America?
“The situation is not dissimilar to the LA-San Francisco region of southern California.”

Prof Ian Main, Professor of Seismology and Rock Physics, University of Edinburgh, said:

1. How is the really strong mag 7.5 second shock is related to the first mag 7.8? It may not technically be an aftershock but presumably it was triggered by the first quake?
“Yes, some definitions of the word ‘aftershock’ exclude events that are similar in size to the mainshock, or occur away from the main cloud of events that cluster around the initial rupture. However, this is a semantic issue, or one of classification. The second event almost certainly occurred as a result of triggering by the stress transferred either by the slip on the mainshock rupture, or by the radiated seismic waves. It would be an extremely rare coincidence if they were not related, given they might only have occurred separately at an average rate of one per hundred years or so. This means the second event would have happened sooner or later, but its timing was almost certainly brought forward by the stress perturbation of the first.
“Exceptionally, a smaller event can even trigger a larger one, as in the case of the 2009 L’Aquila, Italy earthquake. Models which include the idea of triggering, where similar or larger events can be triggered occasionally by stress transfer or radiation, are currently the best at forecasting future seismicity in global testing trials for earthquake population models, and are used in operational forecasting models to help decision-making on the ground in many countries now. The number of events that are triggered does depend on location, with some regions of the world more prone than others.”

Prof Bill McGuire, Emeritus Professor of Earth Sciences at UCL, said:

1. How is the really strong mag 7.5 second shock is related to the first mag 7.8? It may not technically be an aftershock but presumably it was triggered by the first quake?
“Both the 7.8 initial quake, and the 7.5 that followed nine hours later, are located in the East Anatolia Fault Zone (EAFZ), but there is not enough information yet to say if they happened on the same fault. The second quake occurred 90km or so north of the first, and could well have happened on a different fault that was over-stressed and triggered to rupture by the first quake. Based upon the quake magnitudes, the first quake would have resulted from the rupture of a ~200km-long length of fault, while the second would have arisen from a fault rupture around 120km in length.”

2. What does the impact tell you about building design in the region? Are you surprised at the level of damage or loss of life?
“It is clear that many apartment blocks have experience so-called pancake collapse. This happens when the walls and floors are not tied together well enough, and each floor collapses vertically down on the one below leaving a pile of concrete slabs with hardly any gaps between. This means that chances of survival for anyone inside are very small. There should be seismic codes in place to stop this, but they are not well enough enforced. It is not unusual to see one block standing with little damage, and the one next to it – due to dodgy construction or use of poor materials – completely flattened.”

Prof Joanna Faure Walker, Head of the UCL Institute for Risk and Disaster Reduction, said:

“The Turkey earthquake had a magnitude of 7.8 and it released about 250 times the amount of energy as the magnitude 6.2 24th August 2016 Amatrice (central Italy) earthquake that killed three hundred people. The higher magnitude and energy release results in a much larger area affected.

“Of the deadliest earthquakes in any given year, only 2 in the last ten years (2013-2022) have been of equivalent magnitude, and 4 more in the previous ten years. Therefore, earthquakes this large can be the deadliest in any given year.

“Turkey has experienced the deadliest earthquake worldwide four times in the last 50 years (in 2020, 1999, 1983 and 1975) so is no stranger to the deadly consequences of such events. However, Turkey has not experienced the largest magnitude earthquake in any given year over the last fifty years (excluding 2023 in which it is the largest earthquake so far) – because it is not just magnitude, but critically the number of people within the affected area and building construction quality and practice that will determine the fatality figures.

“In 2004, following the devastation caused by the 1999 Izmit earthquake, there was a new law passed by the Turkey Government requiring all construction to follow modern earthquake proof standards – it will be important in the aftermath of the most recent event to check this has been adhered to for all buildings constructed since this date and to review if the requirements are sufficient and whether there is possibility to improve the safety of older buildings.”

Dr Carmen Solana, Reader in Volcanology and Risk Communication at the University of Portsmouth, said:

“Earthquakes cannot be accurately forecast, so prevention of the consequences depend on preparedness (e.g. through earthquake resistant infrastructure) and efficient response. The resistant infrastructure is unfortunately patchy in South Turkey and especially Syria, so saving lives now mostly relies on response. The next 24 hours are crucial to find survivors; after 48 hours the number of survivors decreases enormously.”

Dr Roger Musson, Honorary Research Associate, British Geological Survey, said:

“The earthquake originated at the SW end of the East Anatolian Fault, near the junction with the N-S running Dead Sea Transform, at a depth of about 18 km and propagated to the NE causing heavy damage. This is similar to the 1822 event which completely ruined many towns with heavy casualties (it is hard to get accurate death tolls for historical earthquakes, but in the tens of thousands certainly). In Aleppo alone about 7000 were said to have been killed. Aftershocks of today’s event are continuing, with one of 6.7 magnitude a mere 11 minutes after the main shock. The 1822 earthquake also had many aftershocks, continuing into June the following year.”

Dr Mohammad Kashani, Associate Professor of Structural and Earthquake Engineering at the University of Southampton, said:

“This earthquake occurred in 26km East of Nurdagi at 17.9km depth. It is still too early to make any detailed comments, but from the photos it is evident that several structures have collapsed during in this highly populated area. The photos shows that some of the collapsed buildings may have been built prior to modern seismic design code so they might not be appropriately designed and detailed for such a large magnitude earthquake.

“The combination of large magnitude and shallow depth made this earthquake extremely destructive. We need to investigate the collapsed structures in detail and learn from this devastating event to design our structures and cities to be resilient to such event.”

Prof Bill McGuire, Emeritus Professor of Earth Sciences at UCL, said:

“This a major earthquake that has clearly resulted in widespread devastation. Many of the buildings in the towns affected are simply not designed to cope with this level of strong shaking, and in Syria many structures have already been weakened by more than a decade of war. Sadly, I expect the death toll to rise significantly, and would not be at all surprised by a final death toll in the thousands. There have been dozens of significant aftershocks on the heels of the main quake, and these will continue for days, hampering rescue and relief efforts and potentially causing collapse of already damaged buildings.”

Prof Ilan Kelman, Professor of Disasters and Health at the UCL Institute for Risk & Disaster Reduction, said:

“The Turkey-Syria earthquake shows the horrific challenges of supporting disaster-affected people in a conflict zone. Our research on ‘disaster diplomacy’–how disasters do not typically create peace–suggests little hope that this devastation will significantly reduce violence against Kurds or prevent the border region as a terrorist crossing point. Aside from the logistical challenges of humanitarian aid amid places of violence, experience demonstrates that, sadly, previous enmity tends to supersede saving lives and stopping war over the long-term.”

Prof David Rothery, Professor of Planetary Geosciences at The Open University, said:

“Last night’s earthquake (01:17 GMT) in southern Turkey was magnitude 7.8, which is large by global standards. On average, there are fewer than 20 earthquakes exceeding magnitude 7.0 in any year. The initial rupture for this one happened at a relatively shallow depth of less than 20 km on the East Anatolian Fault. The shaking at the ground surface will have been more severe than for a deeper earthquake of the same magnitude at source. Many of the subsequent aftershocks, although weaker at source, have occurred at shallower depths.

“The fundamental cause of this earthquake is plate tectonic motion. The northward collision of the Arabian plate into Eurasia is forcing the intervening Anatolian plate westwards at a rate of about 2 cm per year. Because of friction along fault lines, the motion is not smooth. Instead strain builds up locally over years or decades until the accumulated stress is strong enough to overcome resistance and rock masses snap past each other in a sudden jerk. In this case, the violence of the shaking at the surface has been strong enough to make buildings collapse, which is probably how most lives have been lost. There may have been landslides too in hilly terrain. The size of the aftershocks, which may continue for days although mostly decreasing in energy, brings a risk of collapse of structures already weakened by the earlier events. This makes search and rescue efforts dangerous.

“Three earthquakes of magnitude 6 have happened in this area since 1970, and the northern Syrian city of Aleppo was severely damaged by magnitude 7 earthquakes in 1138 and 1822.”

Helpful website https://earthquake.usgs.gov/earthquakes/eventpage/us6000jllz/executive

Declared interests

Prof Ilan Kelman: “No interests to declare.”

For all other experts, no reply to our request for DOIs was received.