A 3000-Year Record of Ground-Rupturing Earthquakes along the Central North Anatolian Fault near Lake Ladik, Turkey

Fraser, Jeff
Pigati, J. S.
Hubert-Ferrari, Aurelia
Vanneste, Krıs
Avşar, Ulaş
Altinok, S.
The North Anatolian fault (NAF) is a similar to 1500 km long, arcuate, dextral strike-slip fault zone in northern Turkey that extends from the Karliova triple junction to the Aegean Sea. East of Bolu, the fault zone exhibits evidence of a sequence of large (M-w > 7) earthquakes that occurred during the twentieth century that displayed a migrating earthquake sequence from east to west. Prolonged human occupation in this region provides an extensive, but not exhaustive, historical record of large earthquakes prior to the twentieth century that covers much of the last 2000 yr. In this study, we extend our knowledge of rupture events in the region by evaluating the stratigraphy and chronology of sediments exposed in a paleoseismic trench across a splay of the NAF at Destek, similar to 6: 5 km east of Lake Ladik (40.868 degrees N, 36.121 degrees E). The trenched fault strand forms an uphill-facing scarp and associated sediment trap below a small catchment area. The trench exposed a narrow fault zone that has juxtaposed a sequence of weakly defined paleosols interbedded with colluvium against highly fractured bedrock. We mapped magnetic susceptibility variations on the trench walls and found evidence for multiple visually unrecognized colluvial wedges. This technique was also used to constrain a predominantly dip-slip style of displacement on this fault splay. Sediments exposed in the trench were dated using both charcoal and terrestrial gastropod shells to constrain the timing of the earthquake events. While the gastropod shells consistently yielded C-14 ages that were too old (by similar to 900 yr), we obtained highly reliable C-14 ages from the charcoal by dating multiple components of the sample material. Our radiocarbon chronology constrains the timing of seven large earthquakes over the past 3000 yr prior to the 1943 Tosya earthquake, including event ages of (2 sigma error): A. D. 1437-1788, A. D. 1034-1321, A. D. 549-719, A. D. 17-585 (1-3 events), 35 B. C.-A. D. 28, 700-392 B. C., 912-596 B. C. Our results indicate an average interevent time of 385 +/- 166 degrees yr (1 sigma).


Major Late Cretaceous Mass Flows in Central Turkey Recording the Disruption of the Mesozoic Continental Margin
Okay, Aral; Altıner, Demir; Kylander-Clark, Andrew R. C. (American Geophysical Union (AGU), 2019-03-01)
The newly recognized Upper Cretaceous (similar to 87Ma) olistostrome belt in central Turkey west of Ankara extends for more than 112 km subparallel to the Izmir-Ankara suture with a width of 10 km. The Alacaatl Olistostromes are stratigraphically underlain by a Triassic basement, and are up to 2 km thick. Over 80% of the blocks in the olistostromes consist of pelagic limestones, which reach up to 300 m in size; other blocks include basalt, chert, serpentinite, tuff, and sandstone. The limestone blocks are J...
A critical examination of near-field accelerograms from the sea of Marmara region earthquakes
Akkar, S; Gulkan, P (Seismological Society of America (SSA), 2002-02-01)
In 1999, Turkey was struck by two major earthquakes that occurred 86 days apart on the North Anatolian Fault system. Both earthquakes had right-lateral strike-slip mechanisms with moment magnitudes greater than 7. The number of strong-motion records obtained from the Kocaeli earthquake (17 August 1999, M-w 7.4) was 34. The second event, designated as the Bolu-Duzce earthquake (12 November 1999, M-w 7.2), triggered 20 instruments. Among the records that we have from these earthquakes, seven are from near-sou...
Shear wave splitting along a nascent plate boundary: the North Anatolian Fault Zone
Biryol, C. Berk; Zandt, George; Beck, Susan L.; Özacar, Atilla Arda; Adiyaman, Hande E.; Gans, Christine R. (Oxford University Press (OUP), 2010-06-01)
P>The North Anatolian Fault Zone (NAFZ) is a transform structure that constitutes the boundary between the Anatolian Plate to the south and the Eurasia Plate to the north. We analysed the properties of the upper-mantle strain field and mantle anisotropy in the vicinity of NAFZ via splitting of SKS and SKKS phases. We used data from the North Anatolian Fault (NAF) passive seismic experiment. This is the first study that analyses the upper-mantle anisotropy in this region and our results indicate that the obs...
The Chios, Greece Earthquake of 23 July 1949: Seismological Reassessment and Tsunami Investigations
Melis, Nikolaos S.; Okal, Emile A.; Synolakis, Costas E.; Kalogeras, Ioannis S.; Kanoğlu, Utku (Springer Science and Business Media LLC, 2020-03-01)
We present a modern seismological reassessment of the Chios earthquake of 23 July 1949, one of the largest in the Central Aegean Sea. We relocate the event to the basin separating Chios and Lesvos, and confirm a normal faulting mechanism generally comparable to that of the recent Lesvos earthquake located at the Northern end of that basin. The seismic moment obtained from mantle surface waves, M-0=7x10(26) dyn cm, makes it second only to the 1956 Amorgos earthquake. We compile all available macroseismic dat...
An overview of local site effects and the associated building damage in Adapazari during the 17 August 1999 Izmit earthquake
Bakır, Bahadır Sadık; Sucuoğlu, Haluk (Seismological Society of America (SSA), 2002-02-01)
Two major earthquakes occurred in Turkey along the North Anatolian fault in 1999. The first one, which occurred on 17 August 1999, had a moment magnitude of 7.4 and ruptured the 140-km segment of the fault in the Marmara region. Adapazari, a city with a population of 190,000, which is mostly located on a deep alluvial basin in the near field of the ruptured fault, was among the worst-affected urban areas in the earthquake-affected region. The distribution of damage over the city was highly nonuniform, indic...
Citation Formats
J. Fraser, J. S. Pigati, A. Hubert-Ferrari, K. Vanneste, U. Avşar, and S. Altinok, “A 3000-Year Record of Ground-Rupturing Earthquakes along the Central North Anatolian Fault near Lake Ladik, Turkey,” BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, pp. 2681–2703, 2009, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/46721.