2003 Bam earthquake

Earthquake
title=2003 Bam earthquake
date= December 26, 2003


magnitude = 6.6 M_w
depth=convert|10|km|mi|6United States Department of the Interior (2006).]
location=coord|29.004|N|58.337|E
countries affected = IRN
casualties = 30,000 people dead and 30,000 injured

The 2003 Bam earthquake occurred in the Kerman province of southeastern Iran on December 26, 2003.

The earthquake occurred at 1:58 AM UTC (5:28 AM Iran Standard Time) and its magnitude was estimated by the United States Geological Survey as 6.6 on the Richter scale.

Two documentaries about this earthquake has been produced entitled Bam 6.6 and Voices of Bam.

Background and tectonics

Iran suffers from frequent earthquakes, with minor ruptures occurring almost daily. There is little earthquake education in that country, most believing that if one occurs, it is God's will. Bahram Akasheh, a professor at Tehran University, told "Reuters" that this thinking was "poisonous".

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 (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.United States Department of the Interior (2003)]

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 Bam 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.

The rupture length of the earthquake was estimated to be around 24 kilometers. More than half of the quake was produced from its southern segment of approximately 13 km, where the slip reached a maximum of up to 270 centimeters resulting in a large stress drop of at least 6 MPa. Optical remote sensing data shows that the Bam fault is not a single fault but consists of a 4–5 km wide fault system with the main branch running between the city of Bam and Baravat. The fault ruptured by the Bam earthquake is believed to stretch the northwest branch of this fault system from Bam southward. Based on these results, scientists suggest that the Bam earthquake ruptured a hidden fault and that in this process an unusually strong asperity was involved, causing the widespread devastation of the rupture. [Wang "et al." (2004) p. abstract.]

Damage and casualties

The quake occurred at 1:56 AM UTC (5:26 AM Iran Standard Time) and had its epicenter near the ancient city of Bam."Iran earthquake kills thousands", British Broadcasting Corporation (2003).] At least 30,000 people were killed and 30,000 injured. BBC reported that a large number of victims were crushed while sleeping. Eighty-five percent of buildings and infrastructure in the Bam area were either damaged or destroyed, with 75% of houses being completely destroyed. Maximum intensities were at Bam and Baravat.

An important regional centre during the 16th and 17th centuries, Bam contained many buildings that were not constructed to survive such ruptures. One of the most notable examples of this was the 2,000 year old Bam Citadel, which was destroyed as a result to this quake.

Electricity and water supplies were cut by the earthquake.

Aftermath

Iranian President Mohammad Khatami called the rupture a "national tragedy" and urged all Iranians to help its victims. The United Nations sent experts to coordinate the relief effort. The Red Crescent set up tents to house survivors. Several foreign countries, including Russia, the United Kingdom, Germany, and Spain, sent supplies and rescue workers to the affected area.

The United States offered humanitarian assistance. White House spokesman Scott McClellan spoke on behalf of President George W. Bush: "Our thoughts and prayers are with those who were injured and with the families of those who were killed."

As a result of the quake, two hospitals in Bam collapsed, leaving the remaining hospitals filled. Emergency centers were set up to care for the injured, though many centers did not have enough room to do so.

References

Works cited

*cite web | title = Iran earthquake kills thousands | work = BBC News |publisher=British Broadcasting Corporation| url = http://news.bbc.co.uk/1/hi/world/middle_east/3348613.stm | date=2003-12-26 |accessdate = 2008-08-19
*cite web|url=http://neic.usgs.gov/neis/eq_depot/2003/eq_031226/neic_cvad_ts.html |title=Tectonic Summary: Magnitude 6.6 SOUTHEASTERN IRAN |date=2003-12-25| work = United States Geological Survey |publisher=United States Department of the Interior |accessdate=2008-08-13
*cite web | title = Magnitude 6.6 - SOUTHEASTERN IRAN | work = United States Geological Survey |publisher=United States Department of the Interior | url = http://earthquake.usgs.gov/eqcenter/eqinthenews/2003/uscvad/ | date=2006-10-12|accessdate = 2008-08-13
*cite journal |last=Wang |first=R. |authorlink= |coauthors=Xia, Y., Grosser, H., Wetzel, H-U., Kaufmann, H., Zschau, J. |year=2004 |month=October |title=The 2003 Bam (SE Iran) earthquake: precise source parameters from satellite radar interferometry |journal=Geophysical Journal International |volume=159 |issue=3 |pages=917-922 |id=10.1111/j.1365-246X.2004.02476.x |url=http://www3.interscience.wiley.com/journal/118792924/abstract |accessdate=2008-09-07