1. Quote from M. Nafi Toksoz
(3 September 2013)
I have known Omer Alptekin since his graduate schooldays
some decades ago. I really got to know him better during his
sabbatical visits to MIT. He is an eminent Turkish
seismologist with great skill for extracting information from
seismic data. Among other things, his analysis of source
mechanisms of earthquakes on the northeast and southwest
shores of the Black Sea produced the first evidence of the
Black Sea lithosphere being over-thrust by the Anatolian
and Asian plates.
I wish Omer Alptekin many more productive and healthy
years, as the "DEAN" of the Turkish seismologists.
Nafi

2. Arabia-Eurasia continental collision, active
tectonics of the E Turkey Plateau/Caucasus, and
crustal strain along the Greater Caucasus Thrust
Robert Reilinger, Robert King, Michael Floyd, MIT, USA
Semih Ergintav, Haluk Ozener, Bogazici Univ., Turkey
Rahsan Cakmak, Ali Ozkan, TUBITAK MAM, Turkey
Philippe Vernant, Univ. of Montpellier, France
Simon McClusky, Australian National Univ., Australia
Giorgi Sokhadze, Ilia Univ., Republic of Georgia
Galaktion Hahubia, NAPR, Republic of Georgia
Fakhraddin Kadirov, Geology Institute, NAS, Azerbaijan
Arkadi Karakhanian, IGS, NAS, Armenia
Tamara Guseva, Natalie Rosenberg, UIPE, Russia
Vadim Milyukov, Moscow State Univ., Russia
Special Acknowledgement to:
The late Aykut Barka, the Father of GPS-Geodynamics in Turkey

3. cGPS Sheki, AZ sGPS Nardimli, Georgia

4. Africa-Arabia-Eurasia plate motions
35 Partner Institutions
in
16 Host Countries

5. Geodetic vs. Geologic and Plate Tectonic Rates
Lat (°) Long. (°E) Rate (°/Ma ccw) Ref
31.7 ± 0.2 24.6 ± 0.3 0.37 ± 0.01 JGR 06
32.8 ± 1.2 23.8 ± 2.7 0.39 ± 0.05 DeMets et al. (2010)

6. Implications for Plate dynamics

7. Caucasus seismicity and tectonics

8. E Turkey Plateau/Caucasus
ccw rotation/MCTF shortening

9. GPS Velocities circa 2012

10. Baku, Az. Profile (A)
((note different scales)
1. ~ 11-12 mm/yr shortening over ~ 100 km
2. ~ 8 mm/yr perp., step-wise change (r-l, s-s?)
3. Low deformation (< 1 mm/yr) in Lesser Caucasus

11. Shamakhi, Az., 1667, M6.9 Eq. Profile (B)
1. ~ 10 mm/yr shortening normal to MCTF, ~ 100 km
2. ~ 2 mm/yr right-lateral s-s on MCTF?
3. Lesser Caucasus deformation <95% confidence
4. Similar strain rate to Baku profile

12. Armenia/E Georgia Profile (C)
1. ±2 mm/yr scatter. Stability?
2. ~3-4 mm/yr shortening on KFTB (MCTF?)
3. ~2-3 mm/yr on MCTF
4. ~1-3 mm/yr shortening on N Caucasus thrust

13. Tbilisi Profile (D)
1. ~3-5 mm/yr shortening on KFTB/MCTF
2. ~1 mm/yr, r-l, s-s in Lesser Caucasus?

14. W Georgia Profile (E)
1. ~3-4 mm/yr shortening
2. Too sparse coverage

15. An Illustrative Model
Projection to
surface
MCTF
?
?
NS 15 km
293°/30°/90°/15 km/15 mm/yr160°/45°/135°/15 km/15 mm/yr

16. Ilia/NAPR densification in Georgia

17. GPS/Seismic network expansion in
Azerbaijan (RSSC and GI, NAS)

18. Summary
• International cooperation in GPS is providing a quantitative
framework to understand the kinematics, earthquake hazards, and
plate dynamics for the AR-EU continental collision zone
• To first order, the Lesser Caucasus rotate as a coherent block with
low, but significant internal strain (e.g., 1988 Spitak Earthquake)
• Main strain is focused on the Greater Caucasus Thrust fault system
increasing from ~3 mm/yr in W Georgia to ~ 12 mm/yr in E Az.
• Complex intersecting fault systems at boundary of the Caspian Sea
and the MCTF produce potential seismic and environmental hazards
for an area of expanding population and petroleum infrastructure
• Enhanced GPS observations can provide direct constraints on fault
character (strain accumulation rates, fault locking depths, fault
behavior [creep vs. stick slip], earthquake cycle) for earthquake
hazard estimation and developing effective risk reduction strategies
• There is substantial hazard to cities and infrastructure in the AR-
EU collision zone, including, the most populated from western Turkey
to Turkmenistan (e.g., Istanbul, Tbilisi, Yerevan, Baku, Terhan,
Ashgabat), and many others with populations exceeding 100,000.

19. We are not “prophets of doom”!
Our message is clear and simple:
Know the hazard so you can reduce the risk!
(Denali, Alaska pipeline following 2002, M7.9 Earthquake – a disaster avoided)