Building and Housing Research Center

Iran Strong Motion Network

Catalogue of Earthquake Strong Ground Motion Records(2006)

Editor in Chief : Ph. Dr. S.M. Fatemi Aghda, President of BHRC

Associate Editor : Mirzaei Alavijeh, H., Executive Director of ISMN

Editorial Board : Mirzaei Alavijeh, H., Sinaeian, F., Farzanegan, E., Karimi, P.

and Mirsanjari, M.

Research Report

BHRC Publication No.: R-482

2008

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Since 1973, Building and Housing Research Center (BHRC) with its advanced laboratories and equipments and people has the responsibility for performing various applied research projects on various aspects of building and housing. Its research departments are as follows:

• Architectural and Building Systems• Architectural of Housing and Building Systems• Building Installations• Building Materials and Products • Concrete Technology• Engineering Seismology• Environmental Design and Energy• Fire and Building• Geotechnical Engineering• Iran Strong Motion Network (ISMN)• Structural EngineeringThe idea of establishing BHRC formed in 1970 within the framework of United Nations Development

Program (UNDP). The major objectives for establishment of BHRC are:• Centralized provision and execution of research programs on building and housing by innovation of

new methods and techniques,• Provision and publication of codes of practice and their application instructions,• Issuance of technical certificate for building products and systems,• Provision of technical guidance in construction and housing in compliance with national requirements,

climatic and local considerations• Consideration needed for industrialized construction within the country.The Islamic Republic of Iran is amongst the most seismically active countries. Destructive earthquakes

shake the ground and whatever on it, targeting human lives and buildings. It dictated the needs for researches to prevent or at least to reduce the casualties. Therefore, in 1981, the duties of the earthquake engineering division of the old Management and Budget Planning Organization transferred to BHRC. The main responsibility of this newly established department in BHRC was managing, controlling and maintenance of National Accelerographic Network. This network started with 270 analog instruments at the beginning, and recorded many valuable data of the occurred earthquakes. Because of the importance of to know more about the nature of this destructive phenomenon, at parallel, the other divisions of BHRC also started their researches in the relevant fields. The most important outcome of them was development of the Iranian Codesof Practice for Seismic Resistant Design of Buildings known as Standard 2800 published in 1987 for the firsttime. So far, BHRC has issued two new editions of this Codes of Practice and a large number of the other codes and regulations.

This report deals with the records of the earthquakes occurred in 2006. We are highly determined to continue presenting similar reports in the coming years. I hope it to be useful as a valuable source for those who are interested in this regard.

President of BHRC

Foreword

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In order to reduce the earthquake hazard, a better understanding of seismic phenomenon and its impacts on the buildings and structures is necessary. This has led to increasing research activities in geophysics, engineering seismology and earthquake engineering along with development of the Iran Strong Motion Network (ISMN). Meanwhile, the occurrence of Manjil-Roudbar earthquake in June 20th, 1990, boosted the development of ISMN to 1200 digital accelerographs all over the country within a five years period. Meantime, some of the old analog accelerographs are still at work. This network improvement enabled ISMN to record many weak to strong local earthquakes and provide a comprehensive and valuable strong motion database for the applied studies.

The valuable records gathered via this network, were the main database used by many researches in the field of earthquake engineering and engineering seismology. Therefore, we in BHRC are keen for followingmore improvement and development of ISMN including:

• The installation of new instruments in the seismically active area regarding the past recorded events,• Establishing the dense arrays for fault monitoring,• Establishing the down-hole arrays for site effect investigations,• Installation of accelerographs in most of the tall buildings for structure monitoring,• Installation of accelerographs in special structures including dams and other infrastructural structures

to study their performance during an earthquake.These items were to be considered as the main goals in a successful improvement that was started since

2001. Beside the formal duties, the other activities including presentation of this network among the scientificand engineering communities in the Country were done. The other activities are as following:

• Publishing and distributing the monthly newsletter of ISMN in Farsi as the only source of Strong Motion Data announcement

• Producing a comprehensive accelerographic data bank• Establishing of ISMN webpage on BHRC web site for early information of recorded data for

domestic and international use.At the time being, ISMN runs more than 1100 installed and ready to be triggered accelerographs through

the Country. More than 6600 three-component accelerograms have been recorded, providing the most valuable database for researchers in the fields of engineering seismology, earthquake engineering, geology, seismotectonic and other related fields.

Publishing the information of this databank in english could be a useful guidance for researchers, engineers and college student. In this report as a comprehensive reference, the main recorded accelerograms in Iran along with the last revision of the strong motion parameters are introduced. As a turning point, we had started publishing an english yearly leaflet since 2001 and this is the sixth which is edited for 2006. God willing, we are determined to continue Publishing next series of yearly issues in future. I hope it can be useful for researchers and communities interested in worldwide.

H.Mirzaei AlavijehISMN Executive Manager

Preface

The Strong Motion Network of Iran started its activities in 1973 at the old Planning and Budget Organization. In 1981, the ISMN was transferred to BHRC and a new stage of its activities began. Until 1992, the ISMN had 274 analog accelerographs. At the date of this report, ISMN is consisted of 1082 SSA-2 Accelerpgraphs (digital instrument), 5 CMG-5TD (digital instrument) and 13 SMA-1 accelerographs (analog instrument).

1. Iran Strong Motion Network (ISMN)

Figure1-1. The Map of accelerograph network in 2006

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Figure 2-2. The Epicenters of the earthquakes occurred in Iran in 2006

Figure 2-3. The statistics of earthquakes happened in Iran in 2006

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2.1 Kashkooyeh Earthquake (Kerman Province)

On February 18th, 2006 at 11:03:36 (UTC) an earthquake with Mw4.8 (BHRC), M5.3 (IGTU), Ml5 (IIEES), mb4.8 (EMSC) occurred in the west of Rafsanjan city in Kerman Province, South-East of Iran (Figure 2-1-1). This earthquake was recorded by Iran Strong Motion Network of BHRC, in 7 accelerographic stations of Rafsanjan, Kashkooyeh, Davaran, Bayaz, Baghin, Hosn and Anar. The maximum PGA is as much as 94 gals were recorded at the Koshkooyeh station. This event to the time difference of p and s waves arrival (Ts-Tp) in Koshkooyeh station is estimated to be 4.28 sec, which is nearly equal to 30 kilometer. This epicenter of the earthquake has been located at 30.72N, 55.86E (BHRC), 30.80N, 55.67E (IGTU) and 30.74N, 55.84E (IIEES), 30.84N, 55.75E (EMSC).

Figure 2-2-1. The location map of Kashkooyeh Earthquake of February 18th, 2006 and the trigerred accelerographs

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2.2 Ahmadi Earthquake (Hormozgan Province)

On Tuesday, February 28th, 2006 at 7:31:03(UTC), an earthquake with Mw6.0 (BHRC), M5.9 (NEIC), 5.8 (IGTU), Ms5.9 (IIEES) occurred in the south of Iran in Hormozgan Province (Figure 2-2-1). This event was recorded by 13 sets of digital accelerographs of Iran Strong Motion Network (Figure 2-2-2). The maximum peak acceleration as much as 139 cm/s/s was recorded in Ahmadi station. The epicenter of this event has been located at 28.12 N, 57.01 E (BHRC), 28.27 N, 56.81E (NEIC), 28.18 N, 56.76 E (IIEES) and 28.18 N, 56.54 E (IGTU).

Figure 2-2-1. The location map of the Ahmadi Earthquake of February 28th, 2006 and the trigerred accelerographs

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2.3 Fin Earthquake (Hormozgan Province)

On Saturday, March 25th, 2006 at 07:28:54 (UTC), an earthquake with the magnitude of Mw5.6 (BHRC), M5.9 (NEIC), M6.0 (IGTU), and Ml5.4 (IIEES) occurred in Hormozgan province, south of Iran (Figure 2-3-1). This event was recorded by 4 units of digital accelerograph of Iran Strong Motion Network (ISMN). The maximum acceleration is recorded in Fin station with the peak value of about 194 cm/s/s. The epicenter of this event has been located at 27.73N, 55.78E (BHRC), 27.52N, 55.77E (IIEES) and 27.56N, 55.81E (IGTU).

Figure 2-3-1. The location map of the Fin Earthquake of March 25th, 2006 and the trigerred accelerographs

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2.4 The Foreshocks of Silakhor Earthquake (Lorestan Province)

The first of forshock of Silakhor Earthquake which recorded by ISMN accelerographs happenedon Tuesday, March 30th, 2006 at 16:17:06 with the magnitude of M4.6 (IGUT), Ml4.6 (IIEES) and M4.7 (NEIC). The epicenter of this event is located on 33.55N, 48.85E (IGUT), 33.75N, 48.90E (IIEES) and 33.52N, 48.73E (NEIC).

This foreshock triggered 3 Accelerographs of Chaghalvandi, Boroojerd and Chalan Choolan (Figure 2-4-1).

Figure 2-4-1. The location map of the foreshock of Silakhor Earthquake of March 30th, 2006 and the trigerred accelerographs

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The second foreshock was the greatest foreshock of Silakhor earthquake of March 31st, 2006 that occurred less than 7 hours, before the mainshock on Tuesday March 30th, 2006 at 19:36:16 (UTC) with the magnitude of Mw5.7 (BHRC). This foreshock that caused the peak acceleration of about 320 cm/s/s in ChalanChoolan station, is recorded by 8 accelerograph stations (Figure 2-4-2).

Figure 2-4-2. The location map of the greatest foreshock of Silakhor Earthquake of March 30th, 2006 and the trigerred accelerographs

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2.5 Silakhor earthquake (Lorestan Province)

On Friday early morning of March 31, 2006 at 01:17:02(UTC), an earthquake with the magnitude of Mw5.9 (BHRC), M5.7 (NEIC), M6.0 (IGTU), and Ml6.1 (IIEES) occurred in Lorestan province, west of Iran. This earthquake caused heavy structural damages in the region (Figure 2-5-1). Due to this earthquake 66 people killed and about 1,280 more injured and many buildings in 330 villages surrounding the epicenter destroyed or damaged (Figure 2-5-2, 2-5-3, 2-5-4, 2-5-6, 2-5-7, 2-5-8, 2-5-9 and 2-5-10 show some damages in Darbeastane village). It is likely the death toll would have been much more if the residents had not been warned by a series of weaker foreshocks.

Figure 2-5-1. The location map of the The Silakhor Earthquake of March 31st, 2006 and the trigerred accelerographs

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Figure 2-5-2. Darbeastane Village

Figure 2-5-3. Darbeastane Village

The strong ground motions of this event were recorded by 29 sets of SSA-2 digital accelerographs. The record of Chalan Choolan station (figure2-5-11),withaTs-Tpofabout1.71secondsis the closest obtained accelerogram, which suggests a focal distance of about 12 km. The maximum acceleration was recorded in Chalan Choolan station with the peak value of about 432 and 524 cm/s/s on horizontal and vertical components respectively. The epicenter of this event has been located at 33.69 N, 49.04E (BHRC), 33.48N, 48.86E (IGTU), 33.583N, 48.800E (NEIC) and 33.62N, 48.91E (IIEES). This earthquake had seven foreshocks that are recorded by ISMN. The strongest foreshock was that happened on Tuesday of March 30, 2006, at 19:36:16 (UTC) and described in detail before (Section 2.4). It was followed by many aftershocks as well, and ISMN has recorded about 300 accelerograms in the go after 3 months.

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Figure 2-5-4. Darbeastane Village Figure 2-5-5. Darbeastane Village

Figure 2-5-6. Darbeastane Village Figure 2-5-7. Darbeastane Village

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Figure 2-5-8. Darbeastane Village Figure 2-5-9. Darbeastane Village

Figure 2-5-10. Darbeastane Village Figure 2-5-11. Chalan Choolan Station

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Figure 2-6-2. The location map of the greatest Aftershock of Silakhor Earthquake of March 31st, 2006 and the trigerred accelerographs

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2.11 Dalaki Earthquake (Booshehr Province)

On September 14th, 2006, at 02:25:03 (UTC) an Ml4.6 (IGTU) earthquake in Booshehr Province in South of Iran triggered 4 stations in border region of Fars and Booshehr Provinces. The maximum recorded ground acceleration was 0.153 g at Dalaki station, a small village near Saad Abad town. The seismological parameters such as magnitude and epicenter coordinate were computed by seismo-logical agencies. The epicenter of this event is located at 29.30N, 51.51E (BHRC), 29.23N, 51.34E (IGTU) and 29.26N, 51.36E (NEIC). It should be mentioned that Fars Province and some parts of Booshehr Province are of the most active seismic regions in Iran. (Figure 2-11-1).

Figure 2-11-1. The location map of the Dalaki Earthquake of September 14th, 2006 and the trigerred accelerographs

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2.14 Koloor Earthquake (Gilan Province)

On November 5th, 2006 at 20:06:40 (UTC), an Ml5.6 (BHRC), M5.1 (IGTU), Mw 4.8(KHSN), Ml5.1 (IIEES) earthquake in Gilan Province, North of Iran, triggered 6 stations in border region of Ardebil and Gilan Provinces. The recorded maximum peak ground acceleration was 200cm/s/s at Koloor station, a small town near Khalkhal city (Figure 2-14-1). The seismological parameters such as magnitude and epicenter coordinate were computed and reported by seismological agencies. The epicenter of this event was located at 37.48N, 48.83E (BHRC), 37.566N, 48.848 E (IGTU), 37.48 N, 48.89E (IIEES) and 37.52 N, 49.10E (KHSN).

Figure 2-14-1. The location map of the Koloor Earthquake of November 5th, 2006 and the trigerred accelerographs

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Table1: Recorded Accelerograms during 2006

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Table1: Recorded Accelerograms during 2006

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