Morocco earthquake Why the casualties were so high

A hotel damaged in an earthquake in the village of Mullebrahim, Morocco, on September 10. Xinhua News Agency

The Moroccan Ministry of the Interior said on the evening of September 9, local time, that the strong earthquake that occurred in the country on the evening of the 8th had killed 2,012 people and injured 2,059 people, of which 1,404 were seriously injured. King Mohammed VI declared three days of national mourning and ordered the Royal Armed Forces to dispatch rescue teams.

Why did such a big earthquake happen near Marrakech, Morocco? Why did this earthquake cause such a serious disaster? What are the lessons of the earthquake disaster for China?

Rescuers dig people with their bare hands in the rubble

The epicenter of the quake was in a remote mountainous area about 71 kilometers southwest of Marrakech, Morocco's third-largest city. Many villages lost electricity and communication services, and some roads were blocked by falling boulders, affecting the progress of relief efforts.

Reuters reporters saw in the village of Emizmiz, near the epicenter, that the collapsed brick wall blocked the narrow streets of the area, making it impossible for large machinery and equipment to enter the site, and rescuers were forced to dig people with their bare hands in the rubble. There are long queues outside the village's only open grocery store, and the victims are in desperate need of various daily necessities. Azawa, a villager, remembers the moment of the earthquake and still has palpitations. He said: "I felt that the ground under my feet was shaking, the house was tilting, and I quickly ran outside with my children. But my neighbor's family of four was not so lucky, the bodies of father and son have been found, and the whereabouts of mother and daughter are still unknown. ”

The ancient city of Marrakech, a UNESCO World Heritage Site, was also affected by the earthquake. Videos circulating on social media showed cracks or even collapses in parts of the walls. The historic Koutoubia Mosque was damaged, and its 69-meter-high minaret became known as the "Roof of Marrakech".

Assistance from the international community has not yet been sought

King Mohammed VI of Morocco announced on the 9th that the whole country entered a three-day mourning period, during which flags were flown at half-mast in public places. He ordered the Royal Armed Forces to dispatch rescue teams and set up field hospitals. The Moroccan Government has not formally sought assistance from the international community. However, the leaders and heads of government of many countries in the Middle East issued statements on the 9th to express their condolences and assistance to Morocco.

The United States Geological Survey determined that the earthquake occurred at 23:11 local time on the 8th (6:11 Beijing time on the 9th), with a magnitude of 6.8 and a focal depth of 18.5 kilometers. Nineteen minutes later, another 4.9 magnitude aftershock struck the quake. Morocco's National Geological Monitoring Agency said the quake had a magnitude of 7.0 and a depth of 8 kilometers.

Detectives

Strong seismic activity in the African plate boundary zone is unusually active

Gao Mengtan, researcher and distinguished expert of the Institute of Geophysics of China Earthquake Administration, analyzed that Morocco is located in the border area of the Eurasian plate and the African plate with a strong effect, the Strait of Gibraltar and the Mediterranean coastal area seismic activity is more active, in 2003 Morocco's neighboring Algeria Mediterranean coastal area 6.9 magnitude strong earthquake, in 2004 Morocco Mediterranean coastal area also occurred 6.5 magnitude strong earthquake, in recent years the southern Mediterranean coastal area small seismic activity is also very active.

The 6.9 magnitude earthquake southwest of Marrakech, Morocco, had a certain distance from the plate boundary and was a strong earthquake that occurred inside the African plate, with an epicenter in the Atlas Mountains, and the thrust fault system parallel to the Atlas Mountains was the main culprit. The Atlas Mountains stretch to the Mediterranean coast of Algeria, and the epicenter distribution map of earthquakes of magnitude 2.0 or higher since 2000 shows that the characteristics of earthquakes along the vicinity of the Atlas Mountains are more obvious. Seismic activity above magnitude 6 has not been recorded in this seismic zone for a long time.

Since the beginning of this year, global seismic activity has two characteristics: First, the number of earthquakes above magnitude 7 in the world is relatively large, and it is mainly concentrated in the Eurasian seismic belt, and has caused the most serious casualties in recent years. Second, the strong seismic activity of the African plate boundary zone is extremely active, including the intersection zone of the Eurasian plate and the African plate, the Atlantic Ocean and Indian Ocean ridge seismic belts, etc., and the Red Sea Rift Valley-East African Rift Valley fault zone and the Atlas Mountains seismic zone are also active. The earthquake in Morocco took place against that backdrop.

Local buildings have poor seismic resistance and the collapse process is fast

Gao Mengtan said that the main cause of heavy casualties is the poor earthquake resistance of local buildings. When the 2003 Algerian 6.9 magnitude earthquake killed 2,274 people, injured 11,452 and left more than 200,000 homeless, engineers accompanying the team found that the quality of housing construction was the main cause of heavy casualties. The 2004 6.5 magnitude earthquake off Morocco's Mediterranean coast killed 628 people and injured 926. From the local picture, the damage characteristics of this earthquake are basically the same as before, and the seismic resistance of the buildings has not been fundamentally improved. The proportion of serious injuries among the injured is as high as 68%, indicating that the brittle damage characteristics of house buildings are more obvious, the collapse process is fast, it is easy to form crushing ruins, once collapsed, people have no time to react, the fatality rate and serious injury rate will be very high.

The lessons of this earthquake disaster are very profound. Areas with a strong earthquake background, even areas that have not had a strong earthquake of magnitude 6.5 or higher for decades or even centuries, cannot relax their vigilance, and any neglect of earthquake disasters may pay the price of heavy casualties and property damage. If you want to suffer less damage in an earthquake, you must start by strengthening the earthquake resistance of your house. The results of the recent national earthquake disaster risk survey show that there are still many seismic safety hazards in the eastern part of the mainland, such as old and dangerous houses with low seismic resistance in large cities, buildings in urban villages and suburbs that have not been designed for earthquake resistance, especially multi-storey masonry buildings that do not consider seismic measures well.

Rush to help

China's medical team to aid Morocco provides cash exchange with the Red Cross Society of China

After the earthquake, the CIDCA said that China was willing to provide emergency humanitarian assistance according to the needs of the affected people. The Chinese medical team treated many patients one after another in the aftershock.

The Nandu reporter learned that after the earthquake, the closest station of the Chinese medical team to the epicenter, the Lahamana Hospital in the Bengari area, felt a strong earthquake.

At the risk of aftershocks, the medical staff of the Chinese medical team operated on a number of patients in critical condition one after another, and also witnessed the birth of new life after the earthquake.

Manan, a doctor of the Chinese medical team assisting Morocco, said that medical resources in the entire Moroccan region are now tight, and medical staff are facing more onerous and higher-risk work than before.

Manan said, "In the post-earthquake situation, there has been an obvious shortage of medical equipment in the entire hospital, and the medical team is overcoming difficulties through their own efforts to fulfill the responsibilities of a doctor as much as possible." ”

On the evening of September 9, the Red Cross Society of China said that the earthquake in Morocco had caused heavy casualties and property damage. The Red Cross Society of China decided to provide the Moroccan Red Crescent Society with US$200,000 in emergency humanitarian cash assistance to support its relief work.

Integration: Shi Minglei

Written by: Nandu trainee reporter Peng Yuxin Zhou Minxuan Intern Li Xiaoyi Comprehensive Xinhua News Agency, CCTV News, China Earthquake Administration official number