Publication Date:
2017-04-04
Description:
The November 12, 1999, Mw 7.1 earthquake, ruptured the Düzce segment of the North Anatolian Fault Zone and produced ca. 40 km-long surface ruptures.
To learn about recurrence of large surface faulting earthquakes on this fault, we undertook paleoseismological trench investigations. We found evidence for repeated surface faulting paleoearthquakes pre-dating the 1999 event. Dating was based on radiocarbon and 210Pb analyses as well as on archaeological considerations. By merging information obtained from all the trenches we reconstructed the seismic history of the Düzce fault for the past millennium. We correlated coeval events between different trench sites under the assumption that, similarly to the 1999 event, paleoearthquakes ruptured the whole Düzce fault. Besides the 1999 earthquake, prior surface faulting earthquakes are dated as follows: AD1685-1900 (possibly end of 19th century); AD1685-1900 (possibly close to AD 1700); AD1185-1640; AD685-1220 (possibly AD800-1000). Thus, the AD1719, AD1878 and AD1894 historical earthquakes, may have ruptured the Düzce fault and not the faults they are usually associated to or, alternatively, a cascade of events occurred on the Düzce and nearby faults (similarly to the Izmit and Düzce 1999 earthquakes).
Five events since AD 685-1220 (possibly AD800-1000), would yield an average recurrence time for the Düzce fault, of 200-325 yr (possibly 250-300 yr). The three most recent earthquakes, including 1999, occurred within 300 yr and may be suggestive of clustering. Assuming that the average 1999 slip is characteristic for this fault, the above recurrence times yield slip rates of 6.7-13.5 mm/yr.
Description:
E.C. project Relief (EVG1-CT-2002-00069)
Description:
Submitted
Description:
open
Keywords:
1999 Duzce earthquake
;
paleoseismicity
;
earthquake recurrence
;
04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
manuscript
Format:
8843563 bytes
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Format:
application/pdf
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application/pdf
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application/pdf
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