Seismologist blames accumulated seismic energy for frequent quakes in Iran

News ID: 4280961 -
TEHRAN, Apr. 25 (MNA) – A renowned Iranian seismologist says the frequent jolts across Iran over the past few months are the result of a compensation for the “accumulated seismic energy” in the form of natural consecutive seismic events.

“There has been a lack of sufficient seismicity in the last 20 years, and since the November 2017 earthquake in Kermanshah province, we have possibly been observing a compensation for the accumulated seismic energy in the form of natural consecutive seismic events in the last five months,” Mehdi Zare, professor of engineering seismology at IIEES, says in an interview with the Tehran Times.

Zare also says all assessments show that if an earthquake with a magnitude of 6 or more strikes the metropolis of Tehran more than 100,000 buildings will be destroyed and more than two million buildings will go out of water for at least 14 days.
Following is the text of the interview:

Tehran is the only city in Iran that its municipality is in charge of crisis management. In your view, does the municipality have sufficient means to provide proper aid during a big earthquake or should the task get transferred to another organization?
In fact there are other great cities in Iran (such as Tabriz, Mashhad, Isfahan, Qom, Ahwaz, and Kerman) that municipalities are responsible for disaster management operations. However, the Tehran Disaster Management and Mitigation Organization (TDMMO) is the most developed entity in Iran, having the most expertise, budget and means. The efficiency of TDMMO has not been examined yet in a great earthquake. Compared to other civil organizations related to disaster management in Tehran, I do believe that TDMMO has the best potential and basis for a disaster management operation at any volume in any possible great earthquake in Tehran. In fact, immediately after the recent December 20 earthquake, M=5.2 near the capital, a disaster management meeting was held at Disaster Management Center headquarters and notified other centers in the greater Tehran region. To assess damages in the epicentral region, the information is collected and recorded by Iranian Red Crescent representatives, local water and wastewater organizations, gas and electrical organization authorities, as well as gendarmeries and the other security bodies in the city. In TDMMO masterplan it is expected to provide services such as shelters, food, blood and psychological therapy for the quake victims suffering trauma after a possible magnitude 6 earthquake. At the Red Crescent, the focus is on search and rescue efforts and preliminary food procurement and treatment of victims.

In 2005, the UN rated Iran as the number one country in the world for earthquakes - whether measured in intensity, frequency or the number of casualties. With a population of around 81 million, is Iran relatively prepared to face large earthquakes?  
The seismic hazard zoning map of Iran for "design earthquake" has been constantly updated as an attachment to the different editions of the Iranian seismic building code (the updated version was published and implemented in 2015). Studies have been done using the updated data and methods. There are ongoing efforts to develop the probabilistic seismic intensity zoning maps for the country. There are active fault zones that have been quiescent, with almost no earthquakes, so-called seismic “gaps”. There are major challenges for disaster risk reduction plans near megacities located on seismic gaps in Iran like the two major seismic gaps near Tehran and Tabriz. About 25 million Iranians are living in these zones. There has been some progress in seismic risk preparedness in large cities, but there are still major issues left to deal with in terms of large earthquakes.  

Tehran sits on at least 100 known fault lines. After the most recent earthquake with magnitude 5.2 near the capital on December 20, 2017, where do you think Tehran stands in terms of future quakes?

Very generally we may think about a high risk scenario for the next earthquake. All assessments on deaths, injured and missing across the city of Tehran and the municipalities of the towns surrounding Tehran predict devastating damage for any quake with magnitude of 6 or greater in or around Tehran that may result in the destruction of more than 100,000 buildings. Moreover, a strong earthquake may cause long-term blackouts for more than a million buildings and leave two million buildings out of water for at least 14 days. Beside, large fires, possibly in about 200 tall buildings with more than 10 stories, can create major problems in urban management for at least four weeks after the occurrence of a major earthquake. Explosions and demolition of gas and power stations, which can cause contamination with irreversible damages to the environment, are among the most significant issues of such a  catastrophe, which might be triggered by an earthquake with intensity of 7 (EMS scale). Therefore, it is not unanticipated to imagine this possible earthquake cost at least 10 percent of the annual GDP in the country. This would be the most destructive seismic event in Persian history.

Iran was jolted about 17,000 times over the past calendar year (March 2017-March 2018). What’s the reason behind the unprecedented chain of frequent earthquakes? Is there a scientific explanation for it?

On November 12, 2017, at 18:18 UTC, a major earthquake with moment magnitude Mw7.3 struck Kermanshah province in western Iran which brought about extended damages. Exploring seismicity preceding this earthquake and its comparison to the rate of seismicity after November 12, shows evidently higher seismicity in Iran. The average rate of seismicity in Iran is indicator of about two earthquakes with magnitude M=>7.0 per decade and two M6-7 earthquakes per year in Iran. Looking at the seismicity of the last 20 years prior to the November 12 quake, we find only one M7.8 earthquake in the Saravan region on April 16, 2013 in southeast Iran. Meanwhile, as for M6 to M7 earthquakes over the last 10 years before 12 November 2017, there were only 11 recorded earthquakes instead of about 20 expected earthquakes in that period of time. Therefore, we may conclude that there has been a lack of sufficient seismicity (as a partial response of Iranian plate to tectonic shortening) in the last 20 years, and since 12 November 2017, we have possibly been observing a compensation for the accumulated seismic energy in the form of natural consecutive seismic events in the last five months.

Low grade construction material used for housing construction leaves devastating effects during earthquakes. Your thoughts on that please.
In the last three strong earthquakes in Iran -- Varzeghan in East Azarbaijan province on 12 August 2012, Moormoori in Ilam province on 16 August 2013, and Sarpol-e Zahab on 12 November 2017 -- the newly but poorly constructed houses, including “Maskan- Mehr” buildings, failed to resist the jolts. For example, about 75 percent of 660 victims of the November 12 earthquake in Sarpol-e Zahab were living in the newly constructed buildings. Just about 100 were killed in the Maskan-Mehr buildings in the city.
By September 2017, about 1,850,000 units of Mehr apartments were completed and given to the applicants. In fact, all housing units constructed over the past twenty seven years in Iran were officially built based on Iranian Seismic Building Code (standard No 2800), but there are major questions on the quality of materials and construction methods especially for economically vulnerable people.
Do you believe low standard in housing constructions is carried over to bridges, malls, and government buildings? And in case of large quakes can they withstand strong jolts?
Frankly speaking, I do believe that there are good standards in Iran for construction, but there is no guarantee that high quality construction has been utilized especially in suburban areas and marginal parts of mega cities.

In any natural disaster, trained personnel play a vital role in saving lives when every second counts. In your opinion, are there enough professional rescuers for big quakes? If not, what would you suggest?

Yes, indeed. I do believe that we do have enough potential expertise for rescue, however, they are not competent enough during a major earthquake. The reasons might be listed as: lack of some disciplines, lack of master plan for natural disaster risk reduction especially at the local level in municipalities, missing links in implementation of disaster risk reduction, lack of communication among organizations involved in disaster management and emergency management, absence of disaster response and disaster recovery, and finally lack of a sound and unified incident command system.

Can computer software help rescue humans from natural disasters like earthquakes?

The development of IT especially in the last two decades has improved the quality and effectiveness of earthquake risk reduction plans. This improvement was not performed just in industrially developed countries;  IT was employed in search and rescue efforts in the earthquakes that hit Nepal and Afghanistan in 2015. In these non-developed and poor countries, the application of computer and social networks sped up the rescue efforts and certainly reduced the number of victims.

Over 32,000 buildings sit atop seismic fault lines in the metropolise of Tehran. What do you suggest for residents of such buildings?
In fact, we do deploy crisis management as a comprehensive plan for earthquakes that consists of the Central Council for Disaster Mitigation chaired by first vice-president and assisted by mayor of Tehran in order to conduct a set of cohesive rules for immediate response to disasters. As a result of this plan, in the case of an earthquake, people of Tehran, main government officials that mostly living in the capital, and rescue departments know exactly what to do when the alarm goes off, without chaos.
It wasn’t until the Manjil incident in the 1990 earthquake that crisis management in Iran was reformed under the Interior Ministry. However, this management may not be effective especially in the case of a major earthquake in the capital for lack of a centralized operation system. The early warning system is not yet operational in Tehran (by April 2018); however, the municipality of Tehran has been developing its own system since the year 2010.

The social networks and mobile phone networks have a major responsibility to send an earthquake warning and broadcast the news in advance.
In managing the crisis, one of the most facilitative factors for emergency managers is people’s proper behavior that is to follow instructions precisely. In other words, social capital has a significant role during disaster and afterward. For example, citizens’ respect for values is highly important; they should show sympathy toward each other and avoid looting or try to get relief aid more than what is needed.
The Iranian Red Crescent Society (IRCS), which has a substantial role in the initial relief operations and temporary sheltering, should improve its capabilities especially in Tehran and other great cities and promptly deploy rescue teams. The IRCS is tasked to accommodate homeless people to schools, public buildings and provide shelters for them. The society must coordinate its operations in all other rescue organizations and NGOs to intervene in case of disaster.
The emergency shelters should be settled by a maximum of seven days after an earthquake and the plan should be up and running to construct temporary housing in the quake-stricken urban areas a week after the incident and the first set of buildings is expected to be ready within a month. In addition to medical aid, therapists and social workers should be dispatched to the affected zones by the Health Ministry and with passing time the concentration of treatment should shift from physical injuries to psychotherapy.
After a large quake, fires in oil installations and other refineries may last for a couple of days. Generally, fire fighters and police should take control of fires. It is expected that one million liters of gasoline per day be carried to the damaged areas by tankers.
Since power plants suffer damages and are shut down authorities should impose sporadic power cuts nationwide to make up for production loss. Correspondingly, large factories halt their production activities and many citizens curtail their power consumption in order to limit times of blackout.

How can we make our cities quake-proof?

If earthquakes had been the sole problem in Iran, then the government could have claimed success in planning for the impacts of a major earthquake. The reason for plan deficiencies is the large scale consequences which are yet to be experienced in a great city in Iran. This may cause a greater than tolerable losses. Also, since builders and authorities consider economic benefits and immediate progress above safety and moral factors it has exacerbated the situation. The earthquake disaster is a motivation for people and governments to arrange a nationwide disaster management program and to improve social ethics and their methods in dealing with the problem.



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