1968 Bartın earthquake

1968 Bartın earthquake 1968-09-03 08:19:56 816634 iscgem816634 1968 09 03 10:19:56 Turkey 6.2 w y ISC VIII 20 km on 41.86 N 32.46 E inline,title Thrust One runup at 3 m 24–29 deaths and 200 injured The 1968 Bartın earthquake occurred at 10:19:56 on September 3 with a moment magnitude of 6.3 and a maximum Mercalli Intensity of VIII (Severe). The thrust shock resulted in 24 to 29 deaths and 200 injuries. A tsunami was generated in the Black Sea with a maximum runup height of 3 m. A comprehensive catalogue of tsunamis on the Turkish coast lists the 1968 Amasra event as a definite tsunami, noting inundation distances of 50–100 m along the Amasra–Çakraz shoreline, and ranks it among the most significant Black Sea tsunamis of the 20th century. Earthquake The shock originated on the coast of the Black Sea near Amasra and damage to stone masonry homes was considered heavy between Amasra and Bartin. Ground effects included rock slides, liquefaction, and downslope spreading near rivers. Beaches were raised 40 cm near Amasra and Cape Cakraz, and a 3 m tsunami caused flooding.Ambraseys N. N. Engineering seismology: Part II Earthquake Engineering & Structural Dynamics 17 1 1988 0098-8847 10.1002/eqe.4290170102 56, 57 1988EESD...17...51A In addition to the heavy damage to stone masonry homes between Amasra and Bartın and the tsunami run-up, seismological studies show that the mainshock resulted from movement on a shallow, southeast-dipping thrust fault beneath the southern Black Sea margin. A thrust fault is a type of reverse fault in which the upper crustal block is pushed up and over the lower block. Waveform inversions of long-period compressional (P) and shear (SH) waves indicate the fault plane strikes roughly northeast–southwest (strike ≈ 28°), dips at about 38° to the southeast and slipped with a near-vertical motion (rake ≈ 80°). The average depth of slip (centroid depth) was only ≈ 4 km, and released about 3.9 × 1025 dyn·cm of seismic moment—a standard measure of an earthquake's total energy—which corresponds to a moment magnitude of 6.3. Strong aftershock activity followed: nine aftershocks of magnitude 4.0–4.6 were reported by the International Seismological Centre, five of which occurred on the day of the mainshock. At the nearest station in Kastamonu (roughly 120 km southeast), 256 aftershocks were recorded in the first 24 hours and over 500 within the first week, contributing to widespread alarm and hampering rescue and recovery efforts. Field observations immediately after the earthquake documented up to 0.4 m of coastal uplift near Amasra and numerous landslides, cracks in alluvial deposits and localised ground liquefaction, consistent with the inferred reverse-fault motion. Geological mapping and multichannel seismic reflection profiles show a system of southeast-dipping reverse faults running roughly parallel to the modern coastline about 10 km offshore, implicating active north–south compression of this back-arc basin margin. See also List of earthquakes in 1968 List of earthquakes in Turkey References Alptekin Ömer Nábĕlek John L Toksöz M.Nafi Source mechanism of the Bartin earthquake of September 3, 1968 in northwestern Turkey: Evidence for active thrust faulting at the southern Black Sea margin Tectonophysics 122 1–2 1986 0040-1951 10.1016/0040-1951(86)90159-9 73–88 1986Tectp.122...73A Altınok Y. Ersoy Ş. 2000 Tsunamis Observed on and Near the Turkish Coast Natural Hazards 21 185–205 10.1023/A:1008130512498 ISC-GEM Global Instrumental Earthquake Catalogue (1900–2009) https://www.isc.ac.uk/iscgem/index.php ISC 27 June 2022 International Seismological Centre Version 9.1 10.31905/D808B825 free National Geophysical Data Center / World Data Service (NGDC/WDS) https://www.ngdc.noaa.gov/hazel/view/hazards/earthquake/event-more-info/2559 Global Significant Earthquake Database 1972 NOAA National Centers for Environmental Information 10.7289/V5TD9V7K National Geophysical Data Center PAGER-CAT Earthquake Catalog https://earthquake.usgs.gov/static/lfs/data/pager/catalogs/ September 4, 2009 United States Geological Survey Version 2008_06.1 Albers John Patrick Kalifatcioglu Adnan Open-File Report Bartin-Amasra earthquake, Turkey, September 3, 1968 United States Geological Survey 1972 2331-1258 10.3133/ofr723 Yalçın D. Sertçelik F. 9th Congress of the Balkan Geophysical Society Comparison of 1968 Bartın Earthquake Isoseismal Map And Scenario Earthquake Intensity Maps By Using Gis EAGE Publications BV Netherlands 2017 2214-4609 10.3997/2214-4609.201702569 978-94-6282-236-8 Category:1968 earthquakes Category:Earthquakes in Turkey Category:Tsunamis in Turkey