Rayleigh dalgası Eliptisitesi kullanılarak S- Dalga Hız Yapısının Elde Edilmesi: Erzurum Örneği

Yıl 2020, , 147 - 168, 19.08.2020

Eren Pamuk , Çağlar Özer

https://doi.org/10.17824/yerbilimleri.663521

Öz

S-dalga hızı (Vs) yerel zemin etkilerinin belirlenmesinde ve zemin dinamik analizi çalışmalarında oldukça önemli bir parametredir. Vs, klasik jeofizik yöntemler ile kolaylıkla elde edilebildiği gibi son yıllarda yapılan çalışmalarda Y/D (Yatay/Düşey) temel mod Rayleigh dalgası eliptisitesinin ters çözümü ile de elde edilmektedir. Bu çalışmada Erzurum’da bulunan, Afet ve Acil Durum Yönetimi ve Atatürk Üniversitesi Deprem Araştırma Merkezi tarafından işletilen üç adet deprem istasyonunda kaydedilen gürültü kayıtları yardımıyla her bir istasyona ait bir boyutlu (1-B) S-dalga hız yapısı ortaya konulmuştur. Öncelikle üç istasyon tarafından kaydedilen üç bileşen (D-B, K-G, Z) mikrotremor kaydının sürekli dalgacık dönüşümü yardımıyla temel mod Rayleigh dalgası 
eliptisitesi elde edilmiştir. Sonraki aşamada eliptisite eğrisi Komşuluk Algoritması ile ters çözüm yapılarak 1-B’lu Vs derinlik kesitleri oluşturulmuştur. Son olarak elde edilen 1-B’lu Vs derinlik kesitlerinin doğruluğunu ve güvenilirliğinin sınanması amacıyla Vs derinlik kesitleri yardımıyla teorik Y/D spektral oranları elde edilmiş ve Nakamura yöntemiyle elde edilen Y/D spektral oranları ile karşılaştırılmıştır. Vs değerleri üç istasyon için yaklaşık 160 m derinliğe kadar düşük hata değerleri ile hesaplanmıştır.

Anahtar Kelimeler

Eliptisite, Rayleigh dalgası, Ters Çözüm, Y/D spektral oranları, Erzurum

Teşekkür

Yatay/Düşey Spektral oran ve Elipsitite hesaplamalarında GEOPSY (SESAME 2004) algoritması kullanılmıştır. Şekil 1 GMT programı (Wessel ve diğ. 2013) kullanılarak hazırlanmıştır. İstasyonlara ait jeolojik veriler MTA çizim editöründen alınmıştır (Akbaş vd. 2013). Çalışma alanındaki tektonik birimler (Şekil 1) MTA Diri Fay haritasından sayısallaştırılmıştır (Emre vd. 2013 ve Emre vd. 2018). Yazarlar, bu araştırmaya veri desteği sağlayan T.C. İçişleri Bakanlığı Afet ve Acil Durum Yönetimi Başkanlığı (AFAD) Deprem Daire Başkanlığına ve Atatürk Üniversitesi Deprem Araştırma Merkezine (ATA-DAM) teşekkür eder.

Determining S-wave velocity structure using Rayleigh wave ellipticity: The case study of Erzurum

Öz

S-wave velocity (Vs) is an important parameter in determining local site effects and soil dynamic analysis studies. The Vs can be easily obtained by conventional geophysical methods, but it is also obtained from H/V (Horizontal/Vertical) fundamental mode by inversion of Rayleigh wave ellipticity in recent studies. In this study, one dimensional (1-D) S-wave velocity structures of each earthquake station location were determined by microtremor measurements recorded at three stations operated by Disaster and Emergency Management and Atatürk University Earthquake Research Center in Erzurum. Firstly, the fundamental mode Rayleigh wave ellipticity was obtained by the help of continuous wavelet transform of three components (E-W, N-S, Z) microtremor measurement recorded by three stations. In the next step, 1-D Vs structure was obtained with the inversion of the ellipticity curve with the help of the Neighbourhood Algorithm. Finally, in order to test the accuracy and reliability of the obtained 1-D Vs depth-sections, theoretical H/V ratio spectra was obtained with the help of Vs depth-sections compared with H/V ratio spectra achieved by Nakamura method. Vs values were calculated approximately at 160 m with very low error for three stations. 

Anahtar Kelimeler

Ellipticity, Rayleigh wave, inversion, H/V spectral ratio, Erzurum

Kaynakça

• Akbas, B., Akdeniz, N., Aksay, A., Altun, I., Balci, V., Bilginer E., et al. 2013. Turkey Geological Map, General Directorate of Mineral Research and Exploration, Ankara-Turkey. http://yerbilimleri.mta.gov.tr (Erişim Tarihi: 15.12.2019).
• Aki, K. 1965. A note on the use of microseisms in determining the shallow structures of the earth’s crust. Geophysics, 30(4), 665-666.
• Akkaya, İ., Özvan, A. 2019. Site characterization in the Van settlement (Eastern Turkey) using surface waves and HVSR microtremor methods. Journal of Applied Geophysics, 160, 157-170.
• Bekler, T., Demirci, A., Ekinci, Y. L., Büyüksaraç, A. 2019. Analysis of local site conditions through geophysical parameters at a city under earthquake threat: Çanakkale, NW Turkey. Journal of applied geophysics, 163, 31-39.
• BSSC (Building Seismic Safety Council), 1997. NEHRP recommended provisions for Seismic Regulations for New Buildings and Other Structures. Part I, Provisions (FEMA 302), 334 pp
• Burjánek, J., Poggi, V., Fäh, D., Gassner-Stamm, G. 2011. Estimation of local site effects in the Upper Valais (Switzerland). In Proceedings of 4th IASPEI/IAEE International Symposium: Effects of Surface Geology on Seismic Motion, Santa Barbara, United States. IASPEI and IAEE.
• CEN, 2004. Eurocode 8-Design of Structure for Earthquake Resistance. Part I: General Rules, Seismic Actions and Rules for Buildings. European Standard EN 1998-1, December 2004, European Committee for Standardization, Brussels. crust. Geophysics, 30, 665-666.
• Emre, O., Duman, T. Y., Ozalp, S., Elmaci, H., Olgun, S., Saroglu, F. 2013. 1/1.250.000 scaled Turkey active fault map, General Directorate of Mineral Research and Exploration special publication. Available: http://www.mta.gov.tr/ (July 2, 2019)
• Emre, O., Duman, T. Y., Ozalp, S., Saroglu, F., Olgun, S., Elmaci, H., Çan, T. (2018). Active fault database of Turkey. Bulletin of Earthquake Engineering, 16, 3229-3275.
• Fäh, D., Kind, F., and Giardini, D. 2001. A theoretical investigation of average H/V ratios. Geophys. J. Int., 145, 535–549. (doi: 10.1046/j.0956-540x.2001.01406.x)
• Fäh, D., Kind, F., Giardini, D. 2003. Inversion of local S-wave velocity structures from average H/V ratios, and their use for the estimation of site-effects. Journal of Seismology, 7(4), 449-467.
• Fäh, D., Wathelet, M., Kristekova, M., Havenith, H. B., Endrun, B., Stamm, G., Poggi, V, Burjanek J., Cornou, C. 2009. Using Ellipticity Information for Site Characterisation Using Ellipticity Information for Site Characterisation (Vol. 2, p. 2009). Technical report, NERIES JRA4 Task.
• García‐Jerez, A., Luzón, F., Sánchez‐Sesma, F. J., Lunedei, E., Albarello, D., Santoyo, M. A., Almendros, J. 2013. Diffuse elastic wavefield within a simple crustal model. Some consequences for low and high frequencies. Journal of Geophysical Research: Solid Earth, 118(10), 5577-5595.
• García-Jerez, A., Piña-Flores, J., Sánchez-Sesma, F. J., Luzón, F., & Perton, M. 2016. A computer code for forward calculation and inversion of the H/V spectral ratio under the diffuse field assumption. Computers & geosciences, 97, 67-78.
• Layadi, K., Semmane, F., Yelles-Chaouche, A. 2018. S-wave velocity structure of Chlef City, Algeria, by inversion of Rayleigh wave ellipticity. Near Surface Geophysics, 16(3), 328-339.
• Mirzaoglu, M., Dikmen, Ü. 2003. Application of microtremors to seismic microzoning procedure. Journal of the Balkan Geophysical Society, 6(3), 143-156.
• Nakamura, Y. 1989. A method for dynamic characteristics estimation of subsurface using microtremor on the ground surface. Railway Technical Research Institute, Quarterly Reports, 30(1).
• Nogoshi, M., Igarashi, T. 1971. On the amplitude characteristics of ambient noise (Part 2). J Seismol Soc Jpn, 24, 26-40.
• Ozer, C., Kocadagistan, M.E., Perk, S., 2019. Earthquake monitoring network of Erzurum: ATANET. International Journal of Scientific and Technological Research. Vol.5, No.8, 35-47.
• Özer, Ç. (2019) Erzurum ve çevresinin yerel zemin etkilerinin incelenmesi. Dokuz Eylül Üniversitesi Mühendislik Fakültesi Fen ve Mühendislik Dergisi, 21(61), 247-257.
• Pamuk, E., Doğru, F., Dindar, H. 2015. Yüzey dalgası dispersiyon verisinin ardışık ters çözümü. Yerbilimleri Dergisi, 36(1), 1-18.
• Pamuk, E., Özdağ, Ö. C., Akgün, M. 2019. Soil characterization of Bornova Plain (Izmir, Turkey) and its surroundings using a combined survey of MASW and ReMi methods and Nakamura’s (HVSR) technique. Bulletin of Engineering Geology and the Environment, 78(4), 3023-3035.
• Pamuk, E., Özdağ, Ö. C., Tunçel, A., Özyalın, Ş., Akgün, M. 2018. Local site effects evaluation for Aliağa/İzmir using HVSR (Nakamura technique) and MASW methods. Natural Hazards, 90(2), 887-899.
• Parolai, S., Richwalski, S. M., Milkereit, C., Fäh, D. 2006. S-wave velocity profiles for earthquake engineering purposes for the Cologne area (Germany). Bulletin of Earthquake Engineering, 4(1), 65-94.
• Picotti, S., Francese, R., Giorgi, M., Pettenati, F., Carcione, J. M. 2017. Estimation of glacier thicknesses and basal properties using the horizontal-to-vertical component spectral ratio (HVSR) technique from passive seismic data. Journal of Glaciology, 63(238), 229-248.
• Piña-Flores, J. 2015. Cálculo e inversión del cociente H/V a partir de ruido ambiental. Unpublished M.Sc. Thesis, Universidad Nacional Autónoma de México, México DF, 76 pp. In Spanish.
• Rosa-Cintas, S., Clavero, D., Delgado, J., López-Casado, C., Galiana-Merino, J. J., Garrido, J. 2017. Characterization of the shear wave velocity in the metropolitan area of Málaga (S Spain) using the H/V technique. Soil Dynamics and Earthquake Engineering, 92, 433-442.
• Sambridge M. 1999. Geophysical inversion with a neighbourhood algorithm I. Searching a parameter space. Geophysical Journal International.138:479–94.
• Sánchez-Sesma, F. J., Rodríguez, M., Iturrarán-Viveros, U., Luzón, F., Campillo, M., Margerin, L., García-Jerez A., Suarez M., Santoyo MA., Rodríguez-Castellanos, A. 2011. A theory for microtremor H/V spectral ratio: application for a layered medium. Geophysical Journal International, 186(1), 221-225.
• Schwarz, S.D. and Musser, J.M. 1972. various techniques for making in situ Shear wave velocity measurements- a description and evaluation. Proceedings of the International Conference on Microzonation for Safer Construction, Research and Application.
• Shabani, E., Cornou, C., Haghshenas, E., Wathelet, M., Bard, P. Y., Mirzaei, N., & Eskandari-Ghadi, M. 2008. Estimating shear-waves velocity structure by using array methods (FK and SPAC) and inversion of ellipticity curves at a site in south of Tehran. In Proceedings of the 14th Word Conference on Earthquake Engineering (pp. 12-17).
• TDY (Türk Deprem Yönetmeliği), 2018. Deprem Bölgelerinde Yapılacak Binalar Hakkında Esaslar. AFAD Deprem Dairesi Başkanlığı
• Türkkan, L. 2015. Sürekli dalgacık dönüşümü ile yüzey ölçümü (Yüksek Lisans Tezi, Namık Kemal Üniversitesi).
• Ullah, I. 2017. Near-surface characterization from the H/V spectral curves along with the joint inversion of the ellipticity and dispersion curves.
• Ullah, I., Prado, RL. 2017. Soft sediment thickness and shear-wave velocity estimation from the H/V technique up to the bedrock at meteorite impact crater site, Sao Paulo city, Brazil. Soil Dynamics and Earthquake Engineering, 94, 215-222.
• Wathelet, M., 2005. Array recordings of ambient vibrations: surface-wave inversion. Doktora tezi, Liege Üniversitesi, Belçika.
• Yalcinkaya, E., Alptekin, O. 2005. Site effect and its relationship to the intensity and damage observed in the June 27, 1998 Adana-Ceyhan earthquake. pure and applied geophysics, 162(5), 913-930.
• Yamanaka, H., M. Takemura, H. Ishida & M. Niea, 1994. Characteristics of long-period microtremors and their applicability in exploration of deep layers. Bull. Seism. Soc. Am. 84, 1831-1841.4