12/26/2003 Iranian Earthquake

Updated 1/7/2004

The 6.7 Magnitude earthquake struck at 01:58 GMT 12/26/03. This was 05:28 am local time. The epicenter was in Bam, a city of 80,000, with 200,000 in the surrounding area, in southern Iran, 620 miles southeast of Teheran. The BBC reported within hours of the quake, "A huge relief operation involving ordinary Iranians, the army, Islamic volunteer groups and local rescue teams is under way." The death toll has been estimated at over 30,000 people with over 30,000 injured. Two hospitals collapsed in the quake and remaining ones were strained to help the thousands injured. Electricity and telephone service were knocked out. Over 70% of the houses in Bam are reported to be destroyed.

The quake had been preceeded the night before by a foreshock strong enough to cause some people to sleep out of doors. Undoubtably some lives were saved as people were not inside when houses collapsed. People have continued to sleep outside due to the many aftershocks, which are typical after a major quake.

Relief efforts appear to have been well coordinated at the local level. Teams of people were working to dig out survivors soon after the quake. The dead were quickly buried in mass graves. Health and religious authorities both insisted on quick but respectful burials. Although the huge numbers of dead strained resources, this was accomplished. Trenches were dug with backhoes, groups of about 50 bodies were laid in them and covered with dirt by bulldozers. Then a new trench was started and the process repeated over and over again.

International aid arrived quickly to help survivors and help with reconstrution. Visa requirements were waived for aid workers and for the first time since the revolution 25 years ago, Americans were welcomed into Iran. There is some hope that this could be an opportunity to improve relations between the two countries.

Also destroyed was the Citadel,Arg-e-Bam, mostly dating from the Safavid period in the 16th and 17th C. This was a major historic structure, parts of which date back 2,000 years. As the largest mud brick structure in the world, and a major historic site, it was on the Unesco's list of World Heritage Sites. Bam is on major trade routes to India and the far east, as well as being an oasis in the desert has given it a special importance. The Citadel was a major tourist attraction, the loss of which will be devastating to the nation's cultural heritage and the local economy. Authorities say that it will be reconstructed, but that, of course, is far from the same as having the original.

International aid is on the way, with teams from Russia, Turkey and many other nations. Turkey has been especially responsive with aid teams, following devastating earthquakes in 1999, which raised their awareness of the need for quick aid following large quakes.

Despite frequent large quakes, Iran does not have strong building codes and many houses are built out of mud bricks and unreinforced masonry, which do not stand up well to earthquakes. Mud brick crumbles into a heavy powder without air pockets. Heavy cement roofs collapsed into houses crushing the occupants. Consequently, casualties and damage is much higher than in a similar quake elsewhere in the world. For example, the Northridge quake in Los Angeles in 1994 was a little stronger than this one but only killed about 100 people. In Kobe Japan in 1995 a similar quake killed about 5,000. There too, heavy tile roofs collapsed into many houses. Other factors contribute to the severity of a quake, but earthquake resistant buildings can make a huge different in the number of injuries.

Here is the USGS preliminary report on the causes of the quake:

This earthquake occurred as the result of stresses generated by the motion of the Arabian plate northward against the Eurasian plate at a rate of approximately 3 cm/yr (about one inch per year). Deformation of the Earth's crust in response to the plate motion takes place in a broad zone that spans the entire width of Iran and extends into Turkmenistan. Earthquakes occur as the result of both reverse faulting and strike-slip faulting within the zone of deformation. Preliminary analysis of the pattern of seismic-wave radiation from the December 26 earthquake is consistent with the earthquake having been caused by right-lateral strike-slip motion on a north-south oriented fault. The earthquake occurred in a region within which major north-south, right-lateral, strike-slip faults had been previously mapped, and the epicenter lies near the previously mapped, north-south oriented, Bam fault. However, field investigations will be necessary to determine if the earthquake occurred on the Bam fault or on another, possibly not yet mapped, fault. The December 26 earthquake is 100 km south of the destructive earthquakes of June 11, 1981 (magnitude 6.6, approximately 3,000 deaths) and July 28, 1981 (magnitude 7.3, approximately 1,500 deaths). These earthquakes were caused by a combination of reverse-motion and strike-slip motion on the north-south oriented Gowk fault.

(See the Plate Tectonics page for more information on these processes.)

See also the following news stories:

5/21/2003 Algeria Earthquake

Updated 5/24/2003

The 6.7 Magniture earthquake struck at 18:44 GMT 5/21/03. This was 7:44 pm local time. The epicenter was in Bourmedes, 45 miles east of Algiers in Northern Algeria. Scores of buildings collapsed in the first seconds of the quake. Over 1,875 have died, over 1.000 in Bourmedes and over 7,000 injured. Thousands more camp out in the streets because their homes have been destroyed or out of fear of aftershocks. Accoridng to the BBC, "In Reghaia, 35km (22 miles) east of Algiers, authorities requisitioned the municipal stadium, setting up tents for families whose houses were destroyed in the earthquake. " There have indeed been many strong aftershocks. Rescuers have been desperately digging in the rubble with bulldozers and their bare hands desperately trying to find people who are still alive. After the first two days there is little hope of finding more survivors. Hospitals are totally overwhelmed with thousands of people coming in with serious injuries. Communications are difficult with phone lines down. Many roads have been damaged, huge traffic jams make access to the area difficult. Remote villages are especially cut off with roads cracked and blocked with debris. Large crowds of relatives are pouring into the area, adding to the congestion. Medical supplies are in short supply.

Algeria has requested international aid to cope with the massive damage. France has sent aid, including rescue equipment and rescue dogs. The dogs have been trained to find people under debris. Other countries are also contributing. French President, Jacques Chirac stressed historic ties between France, the former colonial power, and Algeria, in sending aid. UNICEF, the Red Cross and Red Crescent Societies and others are contributing to the effort.

Two days after the quake, crowds turned their grief and anger towards the Algerian President when he toured the disaster area. Boos and stone throwing were reported. Local Newspapers also attack the lack of preparations and response to a quake in this very seismically active region. They accuse the government of an inadequate response and of allowing substandard construction of the buildings that collapsed. The government has been accused of slow response and poor co-ordination of the rescue efforts. Foreign aid workers are finding that government security concerns are also slowing them down. They are experiencing tight checks at the border. Conflicts between government security forces and Islamic militants complicate the issue. Road crews are working with armed escorts and the government is reluctant to send rescuers into areas where they might be caught up in the conflict.

This quake was casued by the collision between the African Tectonic Plate, which is moving northward into Europe. The Northern Algerian area has been hit repeatedly by severe quakes. The USGS describes this process as follows: "The earthquake occurred in the boundary region between the Eurasian plate and the African plate. Along this section of the plate boundary, the African plate is moving northwestward against the Eurasian plate with a velocity of about 6 mm per year. The relative plate motions create a compressional tectonic environment, in which earthquakes occur by thrust-faulting and strike-slip faulting. Analysis of seismic waves generated by this earthquake shows that it occurred as the result of thrust-faulting. Algeria has experienced many destructive earthquakes. On October 10, 1980, the city of El Asnam (formerly Orleansville and today Ech-Cheliff) was severely damaged by a magnitude 7.1 earthquake that killed at least 5000 people. The site of El Asnam is situated approximately 220 km to the west of the recent earthquake. The same city, as Orleansville, had been heavily damaged on September 9, 1954, by a magnitude 6.7 earthquake that killed over 1000 people. On October 29, 1989, a magnitude 5.9 earthquake struck about 110 km to the west of the recent earthquake and killed at least 30 people."

(See the Plate Tectonics page for more information on these processes.)

See also the following news stories:

2/24/2003 China Earthquake

Updated 2/27/2003

The earthquake was given a magnitude of 6.4 by the US Geological Survey. It struck at 02:03 GMT Monday morning. This was 10:03 local time but because the area is in the extreme west of China's one time zone, it was shortly after dawn and many people were at breakfast. Others had just started school or work. The epicenter was in Xinjiang province 65 miles from the city of Kashi. This is in the extreme west of China, 2070 miles west of Beijing. It is generally poor, sparsely populated region, inhabited by Uighurs, a Muslim people, related to those in Kyrgyzstan and other Central Asian countries nearby.

The death toll was confirmed at 266, following strong aftershocks on 2/25/03 that killed 5 more people, including some rescue workers. Estimates of injuries range from 1,000 to 4,000. Over 9,000 buildings were destroyed. Most casualties were caused when people were trapped in their collapsing houses. CNN reported: "Almost all the dead were in Bachu County, where flimsy building construction seemed to have contributed to the death toll, officials said. The neighboring county of Jiashi was closer to the epicenter but suffered little damage; its homes have been reinforced following severe quakes in recent years."

The BBC reported: "The quake had a severe effect on the local economy, which is heavily dependent on farming. Some 11,000 cattle were killed and at just one farm in Qiongkuerqiake, 190 sheep were crushed. Local residents cannot eat them because they have not been butchered according to Muslim tradition. "

The army immediately sent in rescue crews to help dig survivors out of the rubble. Dogs are also being used to locate survivors. The Chinese government is providing aid but has not issued an international appeal.

This quake was casued by the collision between the Indian Sub-continent, which is plowing northward into Asia. This collision raised the Himalayan Range and causes earthquakes throughout the whole Central Asian region. The USGS describes this process as follows:

"This earthquake occurred near the boundary between the Tarim Basin and the Tian Shan mountain range in the north-west Tarim Basin. In a broad sense, earthquakes in this region result from stresses induced by the collision of the Indian and Eurasian continental plates, even though the boundary between these plates lies about 1000 km to the south.

The Indian Plate continuously moves northward at a rate of 4.5 cm per year relative to the Eurasian Plate generating massive mountain ranges including the Himalaya and causing the uplift of the Tibetan Plateau. These stresses are transmitted to the north, through the rigid and undeforming Tarim Basin, where they generate the Tian Shan mountains and numerous earthquakes like this recent event. Several nearby mapped faults have orientations similar to the thrust fault that the earthquake occurred on, although seismologists have not yet associated the quake with a specific fault.

The region surrounding this earthquake has produced several deadly earthquakes in the past decade. The most destructive include a magnitude 6.3 event on March 19, 1996, a magnitude 5.9 on January 21, and a magnitude 6.2 on April 11, 1997. Each quake killed between 10 and 24 people, and destroyed thousands of buildings. The most recent significant earthquake occurred on August 27, 1998 killing 2 and destroying 3,600 homes. " (See the Plate Tectonics page for more information on these processes.)

USGS Bulletin for the 2/24/03 China quake

See also the following news stories: