A New Software For Relationships Between Fault Parameters and Earthquake Size: FaultStat

Currently, in order to perform a well seismic risk analysis for a region, firstly it is necessary to know which structural elements have been shaping the seismic deformation pattern in the region. Segmentation of these structures and identification of their geometric and kinematic characteristics also underpin for seismic risk analysis. In this context, in order to calculate maximum earthquake potential, the surface rupture lengths and maximum displacement amounts of these verifying structures, an assessment with specific approaches both deterministic and probabilistic are progressed. These approaches are outlined (1) through the instrument of seismic data in geophysical and/or in the light of geodetic data (2) based on the geological observations of the surface deformations which created by historical and/or instrumental earthquakes. In the scope of this study, over 500 previous studies that presented on the geological observations are compiled and worldwide data set of 224 historical and instrumental earthquakes are composed and interpreted. On this data, a quality ranking classification has been performed in accordance with geological observations date, measurement technique and the compatibility of the data with the different studies. First earthquakes fau lts are grouped according to their kinematic characteristics, and then a new computer software (FaultStat) has been advanced using parameters such as magnitude -surface rupture length, magnitude -maximum displacement amount are added to the calculations in l inear or logarithmic models. Beside, the software calculates from the data set in its memory, it can also calculate new coefficients for the formulas based upon the new earthquake data entered.Günümüzde bir bölgenin sismik risk analizlerinin sağlıklı bir şekilde yapılabilmesi için, öncelikle o bölgenin sismik deformasyon deseninin hangi yapısal elemanlar tarafından kontrol edildiğinin iyi bilinmesi gerekmektedir. Belirlenen yapısal elemanların, kinematik anlamda türleri, geometrileri ve segment yapılarının ortaya çıkartılması ise sismik risk analizlerinin temelini oluşturur. Bu bağlamda, belirlenmiş yapısal elemanların üretebilecekleri maksimum deprem potansiyelleri ile yaratabilecekleri yüzey kırığı uzunluğu ve maksimum yer değiştirme miktarlarının hesaplanabilmesi için, gerek deterministik gerekse olasılıklar üzerinden belirli yaklaşımlarla bir değerlendirme yapılmaktadır. Bu yaklaşımlar ana hatlarıyla (1) jeofiziksel olarak sismik veriler yardımıyla ve/veya jeodezik veriler ışığında (2) tarihsel ve/veya aletsel dönemde meydana gelmiş depremlerin yarattığı yüzey deformasyonlarının jeolojik gözlemlerine dayanır. Bu çalışma kapsamında, Dünyada meydana gelmiş tarihsel ve aletsel döneme ait depremlerin jeolojik gözlemlerinin sunulduğu 500’ün üzerinde çalışma derlenerek toplamda 224 adet depreme ait bir veri seti oluşturulmuş ve değerlendirilmiştir. Bu veriler üzerinde, jeolojik gözlemlerin yapıldığı zaman, ölçüm tekniği ve verinin kendi içinde farklı çalışmalardaki uyumluluğu dikkate alınarak belirli bir kalite sınıflaması yapılmıştır. Depremleri üreten faylar kinematik özelliklerine göre gruplandırılmış ve daha sonra büyüklük (Mw)-yüzey kırığı uzunluğu, büyüklük (Mw) -maksimum atım miktarı gibi parametreler hesaba katılarak lineer ya da logaritmik modelleri oluşturularak FaultStat isimli yeni bir bilgisayar programı üretilmiştir. Program hafızasındaki veri setinden hesaplama yapmasının yanında, girilen yeni deprem verilerinden yola çıkarak formüller için yeni katsayılar da hesaplayabilmektedir

Seismic history of western Anatolia during the last 16 kyr determined by cosmogenic 36Cl dating.

Western Anatolia is one of the most seismically active regions worldwide. To date, the paleoseismic history of many major faults, in terms of recurrence intervals of destructive earthquakes, their magnitude, displacement, and slip rates is poorly understood. Regional crustal extension has produced major horst-graben systems bounded by kilometer-scale normal faults locally in carbonates, along which vertical crustal displacements occurred. In this study, we explore the seismic history of western Anatolia using 36Cl exposure dating through study of well-preserved carbonate normal fault scarps. To accomplish this, 36Cl concentrations in 214 samples from fault plane transects on the Rahmiye and Ören fault scarps were measured and compared with existing 36Cl measurements of 370 samples on five fault scraps in western Anatolia. At least 20 seismic events have been reconstructed over the past 16 kyr. The age correlation of the seismic events implies four phases of high seismic activity in western Anatolia, at around 2, 4, 6, and 8 ka. Slips are modeled ranging between 0.6 to 4.2 m per seismic event, but are probably the result of clustered earthquakes of maximum magnitude 6.5 to 7.1. While the average slip rates have values of 0.3 to 1.9 mm/yr, incremental slip rates of the faults range greater than 0.1 to 2.2 mm/yr, showing more activity mostly through late Holocene. Our finding reveals high capability of cosmogenic 36Cl dating to explore seismic behavior of active faults beyond the existing earthquake records. Supplementary Information The online version contains supplementary material available at 10.1186/s00015-022-00408-x

Evidence for the reactivation of a pre-existing zone of weakness and its contributions to the evolution of the Kucuk Menderes Graben: a study on the Ephesus Fault, Western Anatolia, Turkey

Detailed geological mapping at the western end of the Kucuk Menderes Graben (KMG) in western Turkey reveals two main sedimentary packages separated by a regional unconformity: (1) Miocene units and (2) KMG basin-fill deposits of Quaternary age. The older basin-fill is represented by colluvial/alluvial fan facies association, which was controlled by a NW-SE-trending and SW-facing dip-slip normal fault (the Ortaburun Fault) and the conformably overlying fluvial and lacustrine deposits. The younger basin-fill, besides being characterised by lateral colluvial fan and axial river sediments deposited under the control of the Ephesus Fault, a southern basin-margin fault character, is also responsible for the evolution of the modern KMG. The analysis of structural, stratigraphic and sedimentological data indicates that three different deformation phases dominated during the Miocene to Recent time in the region: (i) during Early-Middle Miocene Phase 1 deformation (D-1), the NW-SE-trending Ephesus Fault moved as a left-lateral strike-slip fault and occurred within the NE-SW-trending dextral shear zone of the zmir-Balkesir Transfer Zone (BTZ) time; (ii) Middle Miocene Phase 2 deformation (D-2) was associated with Ortaburun Fault, the northern basin-margin fault of the ancient basin. During this phase, the sinistral Ephesus Fault was reactivated as a dip-slip normal fault; and (iii) Phase 3 deformation (D-3) was related with the formation of the KMG during the Quaternary and the Ephesus Fault forms the southern margin of the modern KMG. Structural evidence and computed palaeostress results show that the main extension direction during phase 1 and phase 3 has changed from north-west to north-east direction. This further suggests an approximately 60 degrees rotation around the vertical axes and is attributed to the fact the region lies within the strike-slip dominated BTZ

Evolution of the plio quaternary Soke Milet basin

Pliyo-Kuvaterner Söke-Milet Havzası, Geç Pliyosen-Pleyistosen Fevzipaşa Formasyonu ve güncel alüvyonal, denizel yelpaze deltası ve Büyük Menderes denizel akarsu delta çökelleri ile doldurulmuş, transtansiyonal veya oblik olarak açılmış KD-GB gidişli asimetrik bir havzadır. Havza, Oyukdağ Sıyrılma Fayı ve sağ yanal transfer zonu olarak çalışmış Priene-Sazlı Fayı kontrolünde oluşmuş transtansiyonal supradetachment Miyosen Söke Havzası üzerinde açılmıştır. Miyosen Söke Havzası, kristalin temel kayalar üzerine uyumsuz oturan Söke Formasyonu, Söke ile uyumsuz Davutlar Konglomerası, Davutlar ile uyumlu Kuşadası Formasyonu ve Hisartepe volkanik kaya birimlerini içerir. Miyosen sonuErken Pliyosen sıkışma ve doğrultu atım deformasyonundan sonra, Pliyosen sonundan itibaren transtansiyonal Pliyo-Kuvaterner Söke-Milet Havzası açılmaya başlamıştır. Miyosen kaya birimleri üzerinde uyumsuz olarak bulunan Fevzipaşa Formasyonu, allostratigrafi uyumsuzluğu ile ayrılan altta karasal, üstte sığ denizel yelpaze deltası fasiyes topluluklarını (FA) içeren iki tortul istifden yapılıdır. Bunlar alttan üste, alt alüvyonal yelpaze çökeltileri (FA 1), tatlı su karbonat gölü çökeltileri (FA 2), yelpaze deltası önü (fan-prodelta) çökeltileri (FA 3), sığ denizel yelpaze deltası yamaç çökeltileri (FA 4), kıyı yakını kumlu ağız çubuğu (nearshore sandy mouthbar) çökeltileri (FA 5) ve üst alüvyonal yelpaze çökeltileri (FA 6) dir. Sedimanter fasiyes analizlerine göre, Erken Pleyistosen başında, Söke yöresi ani bir denizel transgresyon etkisinde kalmıştır. Bu denize ait sığ denizel yelpaze deltası 2.40-0.95 My arasında, bağıl olarak tektonik dingin bir dönemde Yamaçköy Fayı önünde birikmiştir. Aşırı tortul yüklü akmalarla oluşmuş alüvyonal yelpazelerden kaynaklanan kum tortullarının kıyıda birikmesi, ilerlemesi (progradation), dalga ve akıntılarla yeniden işlenip çökeltilmesi ve Yamaçköy Fayı tavan bloğunun giderek azalan çökmesi, denizel yelpaze deltası oluşumunu kontrol etmiştir. vii Tektonik aktivite artışına bağlı olarak, Geç Pleyistosen sonu-Holosen oblik açılma döneminde yeniden hareketlenen Priene-Sazlı ve diğer eski fayların denetiminde güncel tortullar çökelerek Büyük Menderes grabenine verev konumlu günümüzdeki havza oluşmuştur. Havza kuzey kenarı günümüze kadar aktif kalmasına karşın güney kenar duraylı veya az aktifdir. Plio-Quaternary Söke-Milet Basin is a transtensional asymmetric basin, trending NE-SW and filled with Late Pliocene-Pleistocene Fevzipaşa Formation and recent alluvial, marine fan-delta and Büyük Menderes marine river delta deposits. The basin was opened on the transtensional supradetachment Miocene Soke Basin that formed under the control of the Oyukdağ detachment fault and Prine-Sazlı Fault activeted as a dextral transfer zone. The Miocene Söke basin consists of Söke Formation resting on crystalline basement rocks unconformably, Davutlar Conglomerate unconformably with Söke, Kuşadası Formation conformably with Davutlar and Hisartepe volcanic rock intrusions. After late Late Miocene-Early Pliocene compressional and strike-slip deformation period, transtensional Pliyo-Quaternary Söke-Milet Basin was began to extend. The Fevzipaşa Formation overlying the Miocene rock units is composed of two sedimentary sequences of the terrestrial at lower part and shallow marine fan-delta facies associations (FA) at upper part, intervaled with an allostratigraphic unconformity. These are; lower alluvial fan deposits (FA 1), fresh water carbonate lake deposits (FA 2), fan-prodelta deposits (FA 3), shallow marine fan-delta slope deposits (FA 4), nearshore sandy mouth-bar deposits (FA 5) and upper alluvial fan deposits (FA 6). Due to the sedimentary facies analysis, the Söke discrict effected from abrupt marine transgression or ingression in the early Early Pleistocene. The shallow marine fan-deltaic deposits related with this marine were deposited in front of Yamaçköy fault between 2.40 and 0.95 Ma in the relatively tectonic quiescience period. The sand deposition on shore coming from hyperconcentrated flow-generated alluvial fans, sand progradation, reworking and redeposition by currents and waves and decreasing subsidence of the hanging-wall block of the Yamaçköy Fault was controlled the deposition of the shallow marine fan-deltaic deposits.ix During the late Late Pliocene-Holocene extension period, due to increasing of the tectonic activity, the recent sediments were deposited control on the reactivated Priene-Sazlı and other ancient faults and, the last basin morphology was formed obliquely to the Büyük Menderes Graben. The northern basin margin is active, while the southern margin inactive or less active in present da

New Findings of Existence Anthropocene in Recent Sediments at Marmara and Black Sea Coast

With each passing day, industrialization, the use of fossil fuels, uncontrolled agriculture and similar human activities are increasing. As a results of these activities, the nature is impacted by a number of changes and anthropogenic pollution. In this study, drilling core samples from the Izmit Bay (IZC-01) in the Sea of Marmara, Surmene (SC-01) and Hopa (HC-01) coasts in the Black Sea have been investigated with lithological, sedimentological, paleontological and geochemical perspectives. The concentrations of heavy metals as Ba, As, Pb, Cd, Cr, Ni, Ti and Zn were considered from total of 45 samples which are covering 15 samples from each three cores. PLI (Pollution load index) values are calculated by using the results of As, Ba, Pb, Cr, Ni, and Zn elements, stand out 3.255 for the Gulf of Izmit, 2,195 and 1,706 for Surmene and Hopa in respectively. PLI values indicate accepted level of pollution above for the Gulf of Izmit and despite being dirty Surmene and Hopa relatively less polluted. In addition, EF values indicate a significant enrichment of the As, M and Cr and moderate enrichment of Pb and Zn elements at Izmit Gulf. In locations Hopa and Surmene; As, Ba and Cr elements showing insufficient enrichment and Ni, Pb and Zn was observed a significant enrichment. Besides, pollution related gypsum crystallization is also remarkable for Maramara core. The abundance and diversity of paleontological records in the cores are also compatible in line with the decreasing and increasing rate of pollution. Towards the deepest part of the all 3 cores, a reduction in the concentrations of elements such as Pb, Zn, Cr and As is seen. Radiocarbon dates obtained, from the shells of these reduction levels are mesured in Surmene 420 +/- 55 (BP) and Hopa 500 +/- 50 (BP). In addition, results of the other previous studies based on sedimentation rate and these ages are compatible. These specified age ranges were compared with opinions in the literature which are related to the beginning of Anthropocene and because of the overlaping, these clearly observed levels have been interpreted as the limit of the possible Anthropocene time

New Geosite Candidates at the Western Termination of the Buyuk Menderes Graben and their Importance on Science Education

The Buyuk Menderes Graben (BMG) is one of the best-known and the largest geological structure of the West Anatolian Extensional Province. It includes two nature conservation parks and twelve cultural heritage sites within and in its vicinity. Four geologically distinct features/locations within and in the vicinity of the BMG have been previously enlisted as geosite candidates in the provisional Geological Heritage Inventory of Turkey compiled in 2002 by the Turkish Association for the Conservation of the Geological Heritage (JEMRKO): (1) the horst-graben structure of the Buyuk Menderes region itself, (2) the tafoni from the augen-gneiss from the east of Bafa Lake, (3) the zultanite crystals from the northeast of lbir Mountain, and (4) the tourmaline (dravite) crystals from the Camzal, Cine. In the current study, we are introducing additional three new geosite candidates at the western termination of the BMG with three different main geological subjects. The first one is the Yavansu Fault. Located 2 km south of the Kuadas village, it has a clearly exposed unique fault surface which is one of the best examples of structural indicators for the WAEP with respect to the normal faulting events. The second one is located in the Hisartepe Volcanics exposed between Kuadas and Soke, and consists of basaltic lava flows with remarkable prismatic cooling joints and a gorgeous feeder dome reaching up to 150 m height. Final suggestion is the Karina marine fan-delta complex located at the south-eastern border of the Dilek Peninsula National Park. This fan-delta complex is the largest one in the Western Anatolian scale and has remarkable paragon outcrops up to 20 m high between Doanbey and Karina Lagoon