THE 1999 KOCAELI AND DUZCE EARTHQUAKES: LESSONS LEARNED AND POSSIBLE REMEDIES TO MINIMIZE FUTURE LOSSES

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1 Seismic Fault-induced Failures, 27-32, 2001 January THE 1999 KOCAELI AND DUZCE EARTHQUAKES: LESSONS LEARNED AND POSSIBLE REMEDIES TO MINIMIZE FUTURE LOSSES D. N. Ural Ph.D., Associate Professor, Department of Civil Engineering, Istanbul Technical University Maslak Istanbul, Turkey, The Kocaeli and Duzce earthquakes that occurred in Turkey in 1999 caused extensive damage and loss of life and property. The policies for mitigation and preparedness of the nation were re-evaluated and new initiatives are being taken in order to minimize possible future losses. The condition where the fault rupture passed through residential and industrial zones during the Kocaeli earthquake caused new level of awareness. An educational mitigation project will be discussed, aimed at preparing, training and educating the local government authorities for disasters. Key Words : Earthquake, Mitigation, Kocaeli, Duzce, Turkey 1. INTRODUCTION 1.1 Earthquake risk in Turkey The Anatolian Fault and Northern Anatolian Fault located in Turkey cause over ninety percent of the country to lie in an active earthquake hazard zone. The challenge for Turkey is to be prepared and minimize losses with proper engineering design, and construction. Proper enforcement of seismic design codes are required. There are lessons to be learned from the recent devastating earthquakes that have occurred in Turkey, which include the 1995 Dinar (M s =5.9), 1998 Adana-Ceyhan (M s =6.1) and 1999 Kocaeli (M s =7.4) and Duzce (M s =7.2) earthquakes. The geotechnical problems seen include liquefaction, landslides, lateral spreading, differential settlement induced failures. Numerous structures sustained damage due to incorrect and inadequate foundation types. Possible remedies and recommendations following the Kocaeli and Duzce earthquakes will be presented in this paper. 1.2 Background information Between the years of 1903 to 2000, there have been nearly 150 earthquakes in Turkey which led to damage. The natural disasters that have occurred are categorized as 61% earthquakes, followed by landslides (15%), floods (14%), rockfalls (5%), fires (4%), and avalanches and storms (1%). The management and plans of these natural disasters in Turkey was first developed in According to the disaster law enacted in 1959, the central government is responsible for the management, and funding for relief supplies The governor, an appointed official, of the province where the disaster occurred, is responsible for coordinating and mobilizing necessary people and equipment. The management is not given to that official at any time. The mayor, an elected official, of the local region affected by the disaster does not have a coordinating or mobilizing role. The mayor is responsible for implementing mitigation measures for possible disasters. 2. KOCAELI AND DUZCE EARTHQUAKES 2.1 Losses incurred The Kocaeli and Duzce earthquakes affected a region of Turkey that constitutes 23% of the countries population. The percentage of the population of Turkey that suffered heavy economic and human 27

2 losses due to the earthquake was 6%. The region was the leading industrial center for Turkey, accounting for 34.7% of the gross domestic product. At the same time, the percentage for the industrial capacity of the earthquake region accounts for 46.7% of the country. The two recent earthquakes resulted in the growth rate of the country declining to negative 1% for the fiscal year of The magnitude M s =7.4 Kocaeli earthquake struck the Marmara Region of Turkey on August 17, 1999 at 3:02 AM local time. The earthquake duration was a lengthy 45 seconds, which caused buildings to collapse and many to tilt under liquefied soil. The epicenter was located along the Northern Anatolian Fault, a right lateral strike-slip fault, at N and E, and at a depth of 15.9 km. Figure 1 Gölcük following the Kocaeli Earthquake. The acceleration records following the Kocaeli Earthquakes, and the distances to the epicenter are listed in Table 1. Table 1 Acceleration records from the Kocaeli Earthquake. Location Distance from Fault (km) Peak Acceleration (g) Izmit Gebze Iznik Ereğli Çekmece Düzce Göynük Figure 2 Coastal subsidence at Gölcük. Table 2 The human losses of the earthquakes. Location Total Number Casualties Population of Injured Bolu 553,022. 1, Bursa 1,958, Eskişehir 660, Istanbul 8,566,823. 3, Kocaeli 1,177,379. 4,149. 4,083. Gölcük 132,857. 5,064. 4,428. Sakarya 731,800. 5,084. 2,627. Tekirdağ 567, Yalova 163,916. 4,472. 2,496. Zonguldak 612, Total 15,125, , ,226. The human losses determined by the Ministry of Public Works and Construction, caused by the major earthquakes are presented in Table 2. Table 3 presents the damage to residential buildings. The numbers presented for light, moderate and heavy damage are given according to the families that have reported their losses. The total number is a result of extensive field investigations of the Ministry of Public Works and Construction. The numbers presented represent the total number of buildings. The typical construction type in the region is a four storey reinforced concrete building with an average of eight dwelling units. Table 3 Total damage reports to buildings. Type of Damage to Buildings Extent of Damage Light 124,000 Moderate 55,000 Heavy 54,000 Total Reported from Ministry 376,665 28

3 The Turkish Government has implemented an aid program for those that had their homes damaged in the earthquake according to the type of damage incurred. (1) Heavy damage or collapse There were four alternatives given by the government to the homeowners whose units incurred heavy damage or collapse. These options included: accepting to live in (i) a prefabricated home, (ii) a government guest house or (iii) a winter tent until a permanent home could be offered, or (iv) accepting to rent a home with government subsidy. rupture from the 1967 Adapazari earthquake. A fence on the boundary of the field had an offset of approximately 3 meters. The initial offset, as stated by the property owner, was 2.6 m. The after slip, or creep after the quake accounted for the remaining 40 cm. The fault rupture passed directly through residential buildings (Fig. 6, Fig. 7), an elementary school (Fig. 4), a highway and overpass (Fig. 5). This damage shows the need for new legislature similar to the situation in the United States. (2) Moderate damage The government offered families and businesses with moderate damage a subsidy to rehabilitate their buildings, or purchase a new unit. (3) Light damage The families and businesses with light damage were offered subsidy to rehabilitate their units. 2.2 Economic losses The economic losses caused by the earthquakes is reported by the Turkish government as 14 Billion US Dollars. This constitutes nearly 21% of the budget of Turkey for the year Earthquake damage mitigation acts Large earthquakes that have taken place in the United States have initiated three important mitigation acts. The situation in Turkey in 1999, also brought to the attention of policy makers, the need for change. Figure 3 Surface fault rupture at Yuvacik. The fault rupture in Yuvacik was followed through open fields, where there were mould cracks, situated approximately 100 m south of the previous fault Figure 4 A school building situated on the rupture in Kullar. (1) Field Act 1933, United States The Field Act was passed following the Long Beach earthquake, in the United States to improve the earthquake design for public schools. (2) Alquist-Priolo Earthquake Fault Zoning Act 1972, United States The Alquist-Priolo act was passed following the 1971 San Fernando earthquake, in California, to mitigate hazards of surface faulting to structures. The Alquist-Priolo Fault Zoning Act s main goal is to prevent construction of buildings on surface trace of active faults. This act requires buildings to be built approximately 50 feet away from the fault surface trace. (3) Seismic Hazards Mapping Act 1990, United States The Seismic Hazards Mapping Act addresses non-surface fault rupture seismic hazards including liquefaction and seismically induced landslides. Many examples of liquefaction were observed following the Kocaeli earthquake, in the city of Adapazari (Fig. 8). As the Northern Anatolian Fault crosses across many residential and industrial regions, new acts are 29

4 Figure 5 Overpass collapse at fault rupture in Arifiye. Figure 7 Home situated on fault rupture in Arifiye. Figure 6 New construction at Yuvacik on fault rupture. required in Turkey, specifying a zone around the fault as a region where construction will not be permitted. 2.4 Mitigation initiative in Turkey Following the Kocaeli and Duzce earthquakes in 1999, a need for planning, training and exercises was addressed as a mitigation tool for future natural disasters. To provide for this need, the Istanbul Technical University and the Federal Emergency Management Agency of the United States made an agreement in order to train future trainers in Turkey. The project has a goal of training a selected group of Istanbul Technical University faculty members, who will later train local and central government officials in charge of disaster affairs. This education project consists of 7 months of train-the-trainer courses, which will be followed by on location training. Through this educational ACHIEVE (A Cooperative Hazard Impact reduction Effort Via Education ) project, the government officials and Figure 8 Apartment affected by liquefaction in Adapazari. later, the public will prepare themselves for a possible future natural disaster. 3 CONCLUSIONS The two major earthquakes that affected the most prosperous region, the Marmara Region of Turkey, caused extensive human and economic losses. The fault rupture passed through residential areas, industrial facilities, schools causing heavy losses. Legal updates to building policies are needed to minimize future losses. The recommendations and actions following these earthquakes include initiating a national educational program to prepare officials and the public to raise awareness and preparedness for natural disasters. 30

5 REFERENCES Coburn, A. ve R. Spence [1992] Earthquake Protection, John Wiley & Sons Ltd., England, UK. Coburn, A., R. Spence ve A.Pomonis [1991] Vulnerability and Risk Assessment, UNDP Disaster Management Training Programme. Comfort, L. Ed. [1988] Managing Disaster, Duke University Press, North Carolina, USA. U.S. Federal Emergency Management Agency [1998] Project Impact Report, USA. Fischer, H.W. [1994] Response to Disaster, University Press of America Inc., Maryland, USA. Foster, H. D. [1980] Disaster Planning The Preservation of Life and Property, Springer Verlag Inc., New York, USA. Gigliotti, R. ve J. Ronald [1991] Emergency Planning for Maximum Protection, Butterworth-Heinemann Inc., Massachusetts, USA. Herman, R. E. [1982] Disaster Planning for Local Government, Universe Books, New York, USA. Karaca, M. and D.N. Ural [1999] Proceedings for the ITU-IAHS International Conference on the Kocaeli Earthquake, 17 August Munasinghe, M.and C. Clarke [1994] Disaster Prevention for Sustainable Development, The World Bank, Washington DC, USA. Raphael, B. [1986] When Disaster Strikes, Basic Books Inc, NY, USA. Stephenson, R.S. [1991] Disasters and Development, UNDP Disaster Management Training Programme. Ural, D. [1999] Disaster Policies and the Economic Impact of Disasters: A Case Study for Turkey, METU Disaster Management Implementation and Research Center, METU/DMC Wallace, W. A. [1990] On Managing Disasters Nothing to Fear, University of Arizona Press, Tucson, Arizona, USA. Wright, J. ve P. Rossi Eds. [1981] Social Science & Natural Hazards, ABT Associates Inc., Massachusetts, USA. 31

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