The ancient city of Kibyra in southwest Turkey has the potential to reveal the location and date of historical earthquakes. The most compelling evidence for earthquake faulting is observed in the city's Roman stadium. Damage related to seismic shaking is characterized by systematically collapsed columns, dilated and collapsed walls, and by rotated and displaced blocks in the stadium. Detailed archaeoseismological observations suggest that Kibyra was affected by earthquakes that were also recorded in historical earthquake catalogs. Although there is no historical record of a large earthquake after the 5th century A.D., Optically stimulated luminescence (OSL) dating of deposits under the collapsed blocks suggests a later seismic event. OSL results indicate that another large event occurred in southwest Turkey, probably around the 10–11th century A.D., and caused extensive damage (Io = VIII‐IX) to the Kibyra stadium.

No abstract

Paleoseismologic trenches excavated across the eastern part of the North Anatolian fault at Yaylabeli, Turkey, provide evidence for fi ve surface ruptures during the past 2000 yr. We interpret these events as: (1) the historical 1939 M w 7.9 earthquake; (2) the historical 1254 A.D. earthquake; (3) the historical 1045 A.D. earthquake; (4) an earthquake that occurred between 660 A.D. and 1020 A.D., most probably between 717 A.D. and 844 A.D.; and (5) an earthquake that occurred between 302 A.D. and 724 A.D., possibly the historical 499 A.D. event. Although one of the interevent intervals we document is 685 yr long (between the 1254 A.D. and 1939 A.D. earthquakes), the other three intervals are between 200 and 350 yr long. Our results, which facilitate a rare opportunity to test the completeness of the paleoseismologic record at multiple sites, are generally similar to those from the nearby Çukurçimen trench site, located 2 km to the east, demonstrating reproducibility of the paleoearthquake record. However, the eighth-to ninth-century event (E4) that we document at Yaylabeli was not observed at Çukurçimen. The addition of this event facilitates the recognition of a previously unnoticed North Anatolian fault earthquake cluster, during which at least the eastern and central parts of the fault appear to have ruptured during a brief sequence in the eighth and ninth centuries. Addition of this possible cluster suggests that the North Anatolian fault commonly ruptures in brief, systemwide sequences, although the individual earthquakes in each sequence differ from cluster to cluster in terms of location, magnitude, and rupture sequence. These paleoearthquake data reinforce the idea of relatively regular recurrence of infrequent, large-magnitude earthquakes on the eastern section of the North Anatolian fault. We attribute this relatively simple behavior to the structural maturity of the North Anatolian fault and its relative isolation from other major seismic sources within the Anatolia-Eurasia plate boundary.

No abstract

No abstract