Determination of Crustal Deformation Field Utilizing Geodetic and Seismic Data

Öz

In this study, velocity field and strain rates were obtained by GPS velocities solely and GPS data with constraints from seismicity.The study area is the western part of North Anatolian Fault Zone NAFZ . The algorithm developed by Haines and Holt was applied to the dataset. Geodetic data were GPS velocities 2003-2005 and seismic data were focal mechanism solutions of earthquakes with magnitude larger than 4 in a 30-year time interval. Results show that the east-west shortening of western NAFZ are related to right-lateral faulting. The minimum velocity value by the evaluation of GPS campaigns is 0.42 mm/yr and the maximum velocity is 25 mm/yr. The south branch of western NAFZ have movements towards west and south-west direction. Strain rates show the north-south extension of the western NAFZ

Anahtar Kelimeler

• GPS, Strain, Earthquake Focal Mechanisms, Deformation, NAFZ.

Jeodezik ve Sismik Verilerden Yararlanarak Kabuk Deformasyonu Alanının Belirlenmesi

Öz

Bu çalışmada, GPS hızları ve jeodezik veri ile zorlanmış sismik veriler kullanılarak hız alanı ve gerinim oranları elde edilmiştir. Çalışma alanı Kuzey Anadolu Fay Zonu KAFZ batı kesimidir. Haines ve Holt tarafından geliştirilen algoritma kullanılmıştır. Jeodezik veri, GPS hızlarıdır 2003-2005 . Sismik veriler, 30 yıllık zaman aralığında büyüklüğü 4’ün üzerindeki depremlerin odak mekanizması çözümleridir. Elde edilen sonuçlardaki doğu-batı kısalması Kuzey Anadolu Fay Zonu batı kesiminin sağ yanal atımlı karakteristiğini yansıtmaktadır. GPS kampanyalarından elde edilen minimum hız 0.42mm/yıl, maksimum hız 25mm/yıl’dır. Güney koldaki hareket batı-güneybatı yönündedir. Gerinim oranları Kuzey Anadolu Fay Zonu batı kesimindeki kuzey-güney genişlemesini göstermektedir.

Anahtar Kelimeler

• GPS, Gerinim, Deprem Odak Mekanizmaları, Deformasyon, KAFZ.

Kaynakça

1. AKAY G. ve OZENER H.: Investigation of long period crustal deformation on the silent branch of the North Anatolian Fault, Nat. Hazard Earth Syst. Sci., 9 (2009), 663-671.
2. AMBRASEYS N. N. ve FINKEL C. F.: Long-term Seismicity of Istanbul and of the Marmara Sea Region, Terra Nova, 3 (1991), 527-539.
3. AYHAN M. E., DEMİR C., LENK O., KILICOGLU A., ALTINER Y., BARKA A. A., ERGINTAV S., OZENER H.: Interseismic Strain Accumulation in the Marmara Sea Region, B. Seismol. Soc. Am., 92 (2002), 216-229.
4. BARKA A. ve REILINGER R.: Active Tectonics of the Eastern Mediterranean Region: Deduced from GPS, Neotectonic and Seismicity Data, Ann. Geofis., XL (1997), 587-610.
5. BEAVAN, J. ve HAINES, J.: Contemporary Horizontal Velocity and Strain Rate Fields of the Pacific-Australian Plate Boundary Zone Through New Zealand, Journal of Geophysical Research, 106 (2001), 741-770.
6. DEMİR, C.: Investigation of Horizontal Crustal Motion and Strain Accumulation in Western Part of North Anatolian Fault, Doktora Tezi, YTÜ Fen Bilimleri Enstitüsü, İstanbul, 1999.
7. ERGINTAV S., BURGMANN R., MCCLUSKY S., CAKMAK R., REILINGER R. E., LENK O., BARKA A., OZENER H.: Postseismic Deformation near the Izmit Earthquake (17 August 1999, M 7.5) Rupture Zone, B. Seismol. Soc. Am., 92 (2002), 194-207.
8. ERGINTAV S., DOGAN U., GERSTENECKER C., CAKMAK R., BELGEN A., DEMIREL H., AYDIN C., REILINGER R.: A Snapshot (2003–2005) of the 3D Postseismic Deformation for the 1999, Mw = 7.4 Izmit Earthquake in the Marmara Region, Turkey, by First Results of Joint Gravity and GPS Monitoring, J. Geodyn., 44 (2007), 1-18.

9. HAINES, A.J. ve HOLT, W.E.: A Procedure to Obtain the Complete Horizontal Motions Within Zones of Distributed Deformation From the Inversion of Strain Rate Data, Journal of Geophysical Research, 98 (1993), 12057-12082.
10. HAINES, A.J., JACKSON, J.A., HOLT, W.E., AGNEW, D.C.: Representing Distributed Deformation by Continuous Velocity Fields, Sci. Rept. 98/5, Inst. of Geol. and Nucl. Sci., Wellington, New Zealand, 1998.
11. HOLT, W. E. ve HAINES, A. J.: The Kinematics of Northern South Island New Zealand Determined From Geologic Strain Rates, Journal of Geophysical Research, 100 (1995), 17991-18010.
12. KOSTROV, V.V.: Seismic Moment and Energy of Earthquakes, and Seismic Flow of Rocks, Izv Acad. Sci., USSR, Phys, Solid Earth, English Translation, 1 (1974), 23
13. KREEMER, C., HOLT, W.E., GOES, S., GOVERS, R.: Active Deformation in Eastern Indonesia and the Philippines From GPS and Seismicity Data, Journal of Geophysical Research, 105 (2000), 663-680.
14. MEADE B. J., HAGER B. H., MCCLUSKY S. C., REILINGER R. E., ERGINTAV S., LENK O., BARKA A., OZENER H.: Estimates of Seismic Potential in the Marmara Sea Region from Block Models of Secular Deformation Constrained by Global Positioning System Measurements, B. Seismol. Soc. Am., 92 (2002), 208-215.
15. OZENER H., DOGRU A., UNLUTEPE, A.: An Approach for Rapid Assessment of Seismic Hazards in Turkey by Continuous GPS Data, Sensors, 9,1 (2009), 602-615.
16. REILINGER R. E., ERGINTAV S., BURGMANN R., MCCLUSKY S., LENK O., BARKA A., GURKAN O., HEARN L., FEIGL K. L., CAKMAK R., AKTUG B., OZENER H., TOKSOZ M. N.: Coseismic and Postseismic Fault Slip for the 17 August, 1999, M= 7.5, Izmit, Turkey Earthquake, Science, 289 (2000), 1519-1524.
17. REILINGER R., MCCLUSKY S., VERNANT P., LAWRANCE S., ERGINTAV S., CAKMAK R., OZENER H., KADIROV F., GULIEV I., STEPANYAN R., NADARIYA M., HAHUBIA G., MAHMOUD S., SAKR K., ARRAJEHI A., PARADISSIS D., AL-AYDRUS A., PRILEPIN M., GUSEVA T., EVREN E., DMITROTSA A., FILIKOV S. V., GOMEZ F., AL-GHAZZI R., KARAM G.: GPS Constraints on Continental Deformation in the Africa- Arabia-Eurasia Continental Collision Zone and Implications for the Dynamics of Plate Interactions, J. Geophys. Res., 111 (2006), B05411, doi: 10.1029/2005JB004051.
18. SHEN-TU, B., HOLT, W. E., HAINES, A. J.: The Kinematics of the Western United States Estimated From Quaternary Rates of Slip and Space Geodetic Data, Journal of Geophysical Research, 104 (1999), 28927-28955.
19. STEIN R. S., BARKA A. A., DIETERICH J. H.: Progressive Failure on the North Anatolian Fault since 1939 by Earthquake Stress Triggering, Geophys. J. Int, 128 (1997), 594-604.
20. URL-1: Global CMT Catalog, Global Centroid Moment Tensor Project, http://www.globalcmt.org/, 03.02.2009.