The 1999 Izmit Earthquake Disaster Report, TurkeyIntroductionIn the year 1999, turkey was hit by a serious earthquake known as the Kocaeli. The Mw 7.
4 earthquake is one of the world’s largest and best studied earth’s horizontal movement (strike slip faults). The earthquake occurred on the east west fault of north Anatolian which is similar to the San Andreas Fault. Actually its this similarity that motivated the extensive study of the fault as the scientist from the US and Turkey wanted to identify the common hazards that the world faces, their report also indicated the implications of the hazards in the near future on both Turkey and the United States of America in a comprehensive report which is available on line. Generally, Turkey has experienced a lot of earthquakes most of them occurring progressively and adjacent to each other.
According to its history, the north Anatolian fault has been producing a series of serious earthquakes and the 1999 Izmit earthquake is the eleventh one since 1939, and had a magnitude of more than 6.7.The Disaster LocationThe locations of the major earthquakes have been shifting in both directions either eastward or westward. This is particularly because of the active seismologic activities; the westward movement has been measured to be about 600km from1939 to 1944 and to make matters worse, the fault is a continuous one.
The west ward movement also increased for about 100km (between 1957 and 1967) more after a short period of slowed activities and further separation of the ruptures during the period around when Izmit earthquake occurred (Hansen 2001).The Izmit earthquake took place on 17th August 1999 on the Anatolian fault area and according to the Kandili Observatory and Earthquake Research Institute (KOERI) the magnitude of the earthquake was 6.7 (Md-Magnitude Duration)(Tang 2000). The epicenter of the earthquake was around the area called Golcuk in western Turkey as indicated in figure 1.
According to the research that was conducted by KOERI, the epicenter was established to be on latitude 40.702N and longitude 29.987E, the seismic data also indicate that the focal depth of the fault was 17 km. the aftershocks affected a larger area including Istanbul which experienced the most activity with a magnitude of Md = 4(Tang 2000).
, however, most of the activities were restricted in the area around the epicenter which include places like Adapazari and Izmit areas, the region around latitude 40.5 to 40.8 N and longitude 29.8 to 30.
0 E, all these were towards the east of the epicenter.Disaster ContextThe area around Izmit gulf (Kocaeli) hosts several commercial and industrial areas and it’s quite an active two. The town of Izmit was established in 8th century and attained its fame as NICO media and has served as the capital of Bithynia kingdom. Since then the city has grown to a modern town experiencing rapid industrialization and as a communication center as it lies on the railway connecting Istanbul and Ankara (Tang 2000).
It is also the main area for paper manufacturing industry which supplies the whole of the country. The town is also a home to other industries like the cement manufacturing industry, textiles industry, tire manufacturing, petroleum and other chemicals plus phosphate industries (Hansen 2001).Figure 1.0: the Location of Izmit earthquake of 1999The major problem is the instability caused by the seismic activities which begun several years ago.
This therefore demands that the construction of buildings be done with a lot of precaution and so much expertise as the tectonic plate movement. The city is surrounded monuments which are ancient walls of the Bithynia Empire and this has made it a popular historic site for tourism (Hansen 2001). Another important feature is the mosque which is believed to have been built in the 16th century.Disaster DriversThe causes of the Izmit earthquakes are attributed to the horizontal movement of the tectonic plates scientifically known as strike-slip movements plus a minimal vertical component.
This disaster was very serious causing a lot of damages to the town of Izmit due to the intense ground disturbance caused by the larger magnitude of the earthquake (Tang 2000). Generally the causes of the Izmit disaster are identified as a combination of the earth’s tectonic plate movements and major sub-aerial or undersea plate sliding.Another serious concern is the secondary emergence of waves say from the tsunami or previous earthquakes as aftershocks. Izmit is located at the bnou8ndaryu between the Eurasian and Anatolian tectonic plates and this is the main reason it experienced a serious damage leaving over 300,000 people homeless, killing a lot of people and causing damage to property especially the infrastructure.
When the plates are moving, fault raptures following undefined path guided by the seismic waves eliciting strong movements (Tang 2000). These ground movements were very intense resulting in very strong ground accelerations and these generates more waves.The Turkish government is working on plans to reduce the loss resulting from the shock waves by removing the infrastructures on the fault path or dislocation of the towns that lie on the Anatolian fault.Hazard MagnitudeThe moment magnitude of the Izmit disaster on the Ritcher scale was established to be about 7.
4 (Mw). The earthquake took place at night and took a period of 45 seconds; most of the people could not comprehend whether it was a dream or reality. To be precise, the KOERI estimated the surface wave to have a magnitude of 7.8, the estimated body wave according the same organizations the body wave have a magnitude of 6.
3 and the duration magnitude was 6.7. These result are evidence that indeed Izmit lies on one of the violent faults lines on the earths surface. The post rapture investigations by the Kandili observatory indicated that the length of the fault areas was more than 860 km ranging from Sapanca on the eastern side to west side Yalova.
Researchers have classified this to be a perfect example of a right angled lateral earth’s horizontal movement where the lateral displacement was estimated to be about 2 to 3 meters and the maximum length being 5.1 meters. These movements are indicated in the following figure 2.0 (Hansen 2001).
Figure 2.0: Plate Tectonic Movements The official results released by Kandili observatory body, the depth of the earthquake was 17km making to be categorized as a shallow earthquake. The standard measure of earthquake disasters is the Ritcher scale, however in the event of other related activities like the tsunami, other types of measures are include for instance the use of the saffir-simpson hurricane scale which is rated from 1 to 5 or the Fujita scale rated from F1 to F6 which is the extreme disaster.Hazard FrequencyOne notable feature of the earthquakes that have occurred in Italy is the cat that they are not consistent presenting a seismic gap as there are some regions of the fault that have not experienced a lot of seismic activities as others in the recent past.
According t the report on the distribution of the earthquakes along the Anatolian fault line by Stein indicated that there was an estimated 12% possibility of a serious earthquake occurring along this fault in a period of three decades (Tang 2000).Thought turkey has had a serious problem with the occurrence of several earthquakes consecutively with the Izmit being the eleventh occurrence in 50 years, there is still not program in place to reduce the possible consequences in future. The plan to dislocate all towns located on the fault line has not yet worked. Most of the seismic activities are inclined towards the west side where there has been a 600km movement between 1939 and 1944 compared to the 100km shift from 1957 to 1967(Gad-el-Hak 2008).
The event of 1999 fills up the gap of events from 1963 to 1964 as cited by researchers like Toksoz, Michael and Shakal in the year 1979 and also by Stein, Dieterich and Barka in 1997 and all these investigations reached a consensus that there was a 12% chance of experiencing a major earthquake between 1996 and 2026and the occurrence of the Izmit disaster is no coincidence. Had precaution been taken, the great loss of life property and the homelessness that resulted could have been avoided. Currently the government has set up a team of experts to try and come up with a solution to this problem. Engineers and other scientists are mapping the fault line of the raptures and evaluating the effects of the earthquake by use of different techniques (Tang 2000).
This is aimed at identifying the areas that are active in seismic events and avoidance of construction of tall buildings in such areas as it would be hazardous.The Lesson of PrecedentThere is documented evidence that earthquakes have been taking place in the Izmit region even in the prehistoric period. In the past years scholars have discovered achieved information which was written by a famous writer named Marcellinus Ammianus in the 4th century. According to the vivid account of the earthquakes in the ancient period by this ancient writer, the details reveal that there is a conspicuous resemblance between the recent earthquakes and the ancient ones.
According to Marcellinus’ description of the shaking ground, the sound in the atmosphere, the collapse of ground on the hillsides and the property destruction that ensued, this is a clear occurrence of earthquakes (Gad-el-Hak 2008). He describes the settling of the dirt that was raised by the landslides after some time following the ground movements and talks of the loss of human life as well.The comparison of these descriptions and the recent events in Turkey show a very close similarity and the resemblance is even closest with the earthquake of 1906 in San Francisco. According to many writers, the occurrence of the 1999 Izmit disaster copulas probably be a repeat of historic events thought in the ancient literature, no faulting on the surface of the earth was not described.
The event dating back to 358 AD is the best explained and most of the features are not so different from the recent (Gad-el-Hak 2008).Effect of Human ActivityIn some cases the human activities may cause earthquakes and it’s therefore advisable to make sure that before some activities are initiated, a preliminary study of the ground be carried out to establish the safety in terms of the possible tectonic plate movements. Some of the human activities that may cause earthquakes or earth tremors include activities like deep drilling, construction of very large water dams, building very large structure like buildings, coal mining, and injecting fluid into wells. Luckily enough the Izmit disaster was as a result of natural causes and not human activities have been linked to the event.
(Hansen 2001).Magnitude of the LossesThe losses experienced from these events include the collapse of both commercial and residential constructions, public infrastructures and a great number of casualties in an area of about 20 to 200 km radius. The suburbs of Istanbul suffered a great deal despite being very far away from the epicenter of the earthquake (more than 100km away). The number of buildings that completely collapsed was about 23,400 while about 16,400 were seriously damaged.
Due to this property damage, over 300,000 people were left homeless while other sources have indicated a population of up to 600,000 people being homeless after the earthquakes and aftershocks (Gad-el-Hak 2008). About 93,000 housing units were completely destroyed and over 220,000 housing units experiencing some degree of damage while over 15,000 business units (smaller businesses) were completely destroyed and 21,000 units were slightly damaged.The number of human deaths that were accounted for was about 18,373 and 48,901 people were hospitalized with serious injuries and it’s estimated that 40% of these people suffered permanent injuries leaving them permanently disabled. The major loss was caused by the two earthquakes namely the Duzce and Kocaeli with the later accounting for about 95% of the total loss that was experienced.
Most of the buildings that collapsed in these events are those located in the southern shorelines of Marmora and the areas around Adapazari (McKinney & Schoch 2003).There was also some loss due to the fire that started after the collapse of the buildings and most of them were contained as the buildings were constructed by non inflammable materials. However serious fire losses were observed in Tupras refinery. The people who were affected most by the earthquakes were the working or upper middle class who were living in storey buildings (McKinney & Schoch 2003)Why So Much LossThe reasons as to why so much destruction of personal property, public infrastructure and loss of lives is the extensive liquefaction, poor planning and other policies of land use that was available at the moment.
Some parts of the Istanbul’s suburbs like the Adapazari were completely destroyed because the city experience intense and extensive liquefaction leading to rapid movement and according to the Kandili observatory, event the reinforced buildings were collapsed.The insufficient soil stricture and condition plus the liquefaction process seem to have played a very big role in the destruction of the major structures. Poor designs of the buildings made them to succumb to the ensuing force and this was attributed to the poor application and material use whereby the earthquake resistant codes were not observed in the construction of the buildings and that the quality of the raw materials used especially the concrete was from a very insufficient quality (Ozkan 2000). Poor reinforcement methods and the soil quality were also closely cited as the main contributors to the increased damage, EERI (1999).
Generally this was a failed land policy system as construction on such type of grounds should not have been allowed by the government in the first place (Kudo et al 2000).The population density did play quite a role in the amount of the destruction that was observed in the Izmit earthquake disaster. Though Turkey had previously experienced similar destructions of earth tremors before especially in the rural areas where the population concentration was very low, precautionary measures had not been seriously implemented even though these features were supposed to be a warning sign for future events which could be even worse as the Izmit disaster indicated (Kudo et al 2000).The many deaths were attributed to the collapse of many residential buildings which were not properly constructed and their designs were very simple to bear the force of the earthquakes.
In fact some of the buildings have the codes that were written in 1942 and very few revisions have been done on them, EERI (1999). However, those that have been changed include the requirement that the earthquake resistant design should be strictly observed according to the report by EERI 1999.Mitigating the Effects of EarthquakesIn an effort to reduce the effects of earthquakes, the possible causes of the tremors must be addressee and the factors that have heightened the level of destruction or loss must also be put into consideration when designing a plan to mitigate the effects of earthquakes in future. The first step to dealing with this issue is to follow a strict building code as established by the EERI where the building will be reinforced by use of proper materials, EERI (1999).
The construction of buildings should be done by the use appropriate and quality cement products. The grounds and soil quality and structure should be studied and approved by engineered before high storey buildings can be constructed. Since the fault line is established, future constructions should not be done near the faulting (Kudo et al 2000)The use of preventive measures is very efficient and this would include educating the public about the earthquakes, the first aid measure to take just incase of the event. The plans and programs that are initiated by the government should be people focused where majority get informed about them.
There should be a strict policy to address the issue of settlement where substructure settlement will be transformed (Kudo et al 2000, Ozkan 2000). The buildings should be reinforced and always bear in mind the effects of the Izmit disaster. This should not be a monster but should be addressed as an issue that can be addressed and solved but not a nightmare (McKinney & Schoch 2003).The Warning of the DisasterThe victims of the disaster narrated very amazing stories about the time prior to the occurrence of the Izmit disaster and this can be explained simply as the warning signs of a disaster that was a bout to come their way.
One of the warning sign is the significant rise in temperature that was experienced during that time with some individual claiming that they could not swim because the waters of the sea were hotter (Kudo et al 2000). The day’s temperature was definitely higher than the normal and that night the sky were observed to be almost red in color and the environment was hotter still.The sea water was seen to be moving in the opposite side of the bay while at that time, fireballs were observed over the surface of the sea. Most people who managed to get out their houses saw how the bricks were being demolished and the way the earth moved causing so much damage to the environment and destroying property (Kudo et al 2000).
Scientists have been trying to find explanations to these strange things that happened but have not found satisfactory supporting evidence.Lessons LearntAfter the disaster there were mixed reactions from different individuals and groups of people about the lessons to be drawn from the experience. Scientists were more concerned about finding the direction of the fault which was also known for a long time, its magnitude and the factors that had set the tectonic plates in motion. The reaction from the general public was that this could be a punishment from God while others believed Armageddon had come.
The best lesson to draw from these experiences is that in everything we do we should do it to the best and with precaution because you never know while a disaster would strike while at the same time most if not all our undertakings are risks and as the old adage goes better prevention of the problem than cure.ReferencesEERI (1999) The Izmit (Kocaeli), Turkey Earthquake of August17, 1999, EERI Special Earthquake Report-Learning from Earthquakes-October1999, retrieved on 24th March 2009 from http://www.eeri.org/Reconn/Turkey0899/Turkey0899.
htmlGad-el-Hak M. (2008). Large-Scale Disasters. Prediction, Control and Mitigation.
Cambridge University PressHansen R (2001) Radar Interferometry: Data Interpretation and Error Analysis SpringerKudo, K. et al (2000), Site Specific Issues on Strong Ground Motion during the Kocaeli, Turkey Earthquake of August 17, 1999, as indirect from Array Observations of Micro tremors and Aftershocks, Submitted to BSSAMcKinney M.L. & Schoch, R.
M. (2003). Environmental Science: Systems and Solutions, 3rd Ed. Jones and Bartlett Publishers.
Sudbury MassachusettsOzkan E (2000). Performance Characteristics of Low Rise Buildings in Izmit Earthquake of August 17th 1999. The Johns Hopkins UniversityTang a (2000) Izmit (Kocaeli), Turkey, earthquake of August 17th 1999 including Duzce earthquake of November 12, 1999. Lifeline performance.