Ali Pinar

Bogazici University · Department of Earthquake Engineering

The Ganos Fault MONGAN earthquake monitoring network data presents significant opportunities and challenges for earthquake detection, location and magnitude calculations, source mechanism solutions, and discovery of fault zone waves. This study consists mostly of primary data analysis and seismological evaluations. While stations located in a local...

1912 yılında iki büyük depremle kırılan Ganos Fayı'nın güncel depremselliği ve gerilme dağılımı fay boyunca önemli farklılıklar gösterir. Kırığın kara ve Saros kesimi asismik (deprem üretmeyen) bir davranış sergilerken, Marmara Denizi içindeki kısmı oldukça yoğun bir deprem etkinliğine sahiptir. Fayın geometrik ve fiziksel özelliklerindeki farklılı...

Most Downloaded Article (Top 3) by Journal of Geodynamics

In the Aegean Sea, the western part of Gökova Gulf, Kos and Bodrum were struck by a 6.6 (Mw) earthquake on July 20, 2017. The fault plane solution for the main shock shows an E-W striking normal type fault with approximately N-S (N4°E) tensional axis (T-axis). Fault plane solutions of 33 aftershocks show two groups of normal type fault with E-W and...

The 30 October 2020 Samos earthquake (Mw 7.0) ruptured an east–west striking, north dipping normal fault located offshore the northern coast of Samos Island, previously inferred from the bathymetry and regional tectonics. This fault, reported in the fault-databases as the North Samos and/or Kaystrios Fault, ruptured with almost pure dip-slip motion...

The studies reported in the literature on train induced vibrations, were mostly performed by locating the instruments in the transversal direction to the railway system. In this study, a horizontal array parallel to the alignment of the railroad was used to record the train induced vibrations. The test site was in close proximity to the Atakoy subw...

The offshore part of the North Anatolian Fault (NAF) beneath the Marmara Sea is a well-known seismic gap for future M > 7 earthquakes in the sense that more than 250 years have passed since the last major earthquake in the Central Marmara region. Although many studies discussed the seismic potential for the future large earthquake in this region on...

In this study, we retrieved the finite source characteristics of the October 23, 2011 Van earthquake (Mw 7.1) using the teleseismic waveforms to focus on the source location. The outstanding off-fault aftershock sequence of the Van mainshock was readily explained by calculating the Coulomb stress changes imparted to the surrounding crust. This may...

The Central Marmara Sea region hosts the northwestern branch of the North Anatolian Fault Zone (NAFZ) with its known seismic gap between the 1912 Ganos (Mw 7.2) and 1999 Izmit (Mw 7.4) major devastating earthquakes and thus poses a significant seismic hazard potential for the megacity Istanbul. The 26 September 2019 Mw 5.7 Silivri High-Kumburgaz Ba...

Imaging and characterizing transform fault sections that are capable to produce large earthquakes is crucial for evaluating seismic hazard and subsequent risk for nearby population centers. The Marmara Fault near the megacity of Istanbul is one of the best defined seismic gaps in the world and its complexity is captured by seismological, geodetic a...

The June 12, 2017 Karaburun-Lesvos (North Aegean Sea) earthquake occurred along the NW-SE trending Lesvos fault, along the southern strand of the North Anatolian Fault Zone. In the present study seismotectonic aspects of the 2017 Karaburun-Lesvos earthquake and its aftershock sequence are studied. A rupture model based on finite source analysis of...

On 30 October 2020, an M 7.0 earthquake occurred north of Samos Island. The fault rupture caused sudden lowering of the seafloor, which produced a tsunami that mainly impacted nearby Samos Island as well as a series of Anatolian cities along the coast of Seferihisar Bay, with maximum runup and inundation lengths of about 3.8 m and 2500 m, resulting...

A Mw 6.8 earthquake struck Western Turkey and Eastern Greece that occurred on October 30, 2020 in Kuşadası Gulf. The earthquake epicentre is located north of Samos Island and the focal mechanism solution shows that a normal fault was reactivated. The main shock and aftershock analysis imply that the large earthquake occurred on a north dipping norm...

Beneath the Marmara Sea, Turkey, the Main Marmara Fault (MMF), the offshore part of the North Anatolian Fault (NAF), is a well-known seismic gap for future M > 7 earthquakes. However, its detailed fault geometry and microearthquake activity have been debated for several decades. Using data acquired from long-term ocean bottom seismograph (OBS) obse...

We studied the source and rupture process of the July 20, 2017 Bodrum-Kos Earthquake (Mw=6.7) to investigate and better understand the source process and coseismic slip distribution. Strong ground motion data with three component were collected from Kandilli Observatory and Earthquake Research Institute, Disaster and Emergency Management Authority...

We have examined the finite fault source characteristics of the October 23, 2011 Erciş-Van earthquake through modelling the seismic waveforms recorded at local and teleseismc distances. A finite source model has been retrieved using the teleseismic body waveforms constraining the source location by info given in previous studies. The finite source...

Frictional coefficient of faults is investigated using the approach described in Iio (1997) where the orientation of a fault plane relative to the maximum compression direction is related through the equation β = 1/2 arctan (1/µ), where β is the angle between the direction of the maximum compression and the fault plane orientation, and µ is coeffic...

The Sea of Marmara accommodates segments of the North Anatolian Fault (NAF) in Turkey and remains the only part of the western NAF that has not ruptured during the last century. At its nearest, the segment is ~20 km from Istanbul, the largest city in Turkey. Thus, it is important to understand the locking state of the fault, since it illuminates th...

Source Characteristics of the January 8, 2013 (MW = 5.7) and May 24, 2014 (MW = 6.8) North Aegean Earthquakes Sequence

Plain Language Summary The North Anatolian Fault (NAF) cuts across the east and west of the Turkish mainland and has repeatedly generated destructive earthquakes (magnitude ~7‐class) to release accumulated strain originating from regional plate motion. The NAF beneath the Sea of Marmara has remained as a “seismic gap” for more than a century and th...

Focal mechanisms of 50 aftershocks (equal/larger than Mw 3.5 since 2011, the Van earthquake) taking place in the NE part of the source rupture area of the devastating Van earthquake (Mw 7.1), E-Anatolia (Turkey) are under investigation in this study. Broadband waveforms recorded at the seismic stations operated by Kandilli Observatory and Earthquak...

Long-period seismic waves have two types. One of them is caused by far-source earthquakes and the other one is caused by near-field type earthquakes. [1]. Long-period seismic waves can be most destructive waves since they amplify their effect when they are passing through the sedimentary areas. There are many examples in literature that shows the d...

The Aegean Sea, is one of the most seismically active areas of the Eastern Mediterranean region (Fig. 1). Generally, North Aegean Sea region has been tectonically developed after the collision of Arabian plate with the Eurasian in the Late Miocene time and the subsequent westward escape of the Anatolian Plate relative to the Eurasian Plate, during...

Abstract It is already well known that the “when, where and how strong” earthquake prediction problem cannot be solved by only analyzing the database from former earthquakes. A possible solution to this problem is proposed herein based on the analysis of the physicochemical processes as participants in earthquake preparation and on the characterist...

The west to southwestward motion of the Anatolian block results from the relative motions between the Eurasian, Arabian and African plates along the right-lateral North Anatolian Fault Zone in the north and left-lateral East Anatolian Fault Zone in the east. The Biga Peninsula is tectonically influenced by the Anatolian motion originating along the...

On 6 February 2017, a moderate-size earthquake occurred at Gülpınar-Ayvacık (Çanakkale) at 6:51 pm local time with the instrumental size ML = 5.5 (Mw = 5.3). The main shock was a shallow earthquake and its depth was 6 km. The depths of aftershocks change between 5 and 20 km. In the days following the earthquake, 4 more earthquakes occured with magn...

2017 YILI AYVACIK-ÇANAKKALE DEPREM AKTİVİTESİNİN SİSMOTEKTONİK ÖZELLİKLERİ

https://authors.elsevier.com/c/1VxFe4t1lLu1ze In this study, we analysed the source mechanisms and faulting pattern of the aftershocks in the Lake Erçek area, Eastern Anatolia, during the 2011 Van event (Mw 7.1). The fault plane solutions of the aftershocks were used to derive a stress tensor acting around Lake Erçek. The estimated seismological p...

The North Anatolian Fault (NAF) is known to sequentially ruptured from the east to the west crossing the Turkish mainland in the past century, which periodically wreaked severe destruction. The latest failures are Izmit and Duzce Earthquakes (1999) just at the east bound of the Sea of Marmara. Thus, the Marmara region remains un-ruptured and is exp...

There have been many destructive earthquakes and tsunamis in the world.The recent events are, 2011 East Japan Earthquake/Tsunami in Japan, 2015 Nepal Earthquake and 2016 Kumamoto Earthquake in Japan, and so on. And very recently a destructive earthquake occurred in Central Italy. In Turkey, the 1999 Izmit Earthquake as the destructive earthquake oc...

Waveform data from two Ocean Bottom Seismograph (OBS) deployments in 2014-2015 and 2015-2016 are utilized to estimate a focal mechanism for the events taking place nearby the Western and Central Marmara fault segment, a part of the North Anatolian Fault (NAF). For each observation, 15 OBS stations were deployed close to Marmara fault with their spa...

Waveform data from two Ocean Bottom Seismograph (OBS) deployments in 2014-2015 and 2015-2016 are utilized to estimate a focal mechanism for the events taking place nearby the Western and Central Marmara fault segment, a part of the North Anatolian Fault (NAF). For each observation, 15 OBS stations were deployed close to Marmara fault with their spa...

Both the geometry and the depth of the seismogenic zone of the North Anatolian Fault under the Marmara Sea (the Main Marmara Fault; MMF) are poorly understood, in part because of the fault's undersea location. We recorded 10 months of microseismic data with a dense array of ocean bottom seismographs and then applied double-difference relocation and...

The North Anatolian Fault (NAF) in the northern Turkey regionally has rightlateral strikeslip motion. In the last decade, seismic activities have been migrating from east to west along the fault. In 1999, Izmit and Duzce Earthquakes were respectively occurred at ~100 km and 200 km east of Istanbul, while it remains unruptured in the vicinity of Ist...

The history of the Late Cenozoic stress regime was determined for an area between the gulfs of Fethiye and Antalya. Fault kinematic analysis and inversion of focal mechanisms of shallow earthquakes reveal significant evolution of the regional stress regime in SW Anatolia, i.e., the area of interaction between the Hellenic and Cyprus arcs, from the...

In this study, focal mechanism of small to moderate size earthquakes in the Sea of Marmara and surroundings are analyzed to determine the deformation and stress regime of the Marmara region. The records of the earthquakes are obtained from the broadband seismic stations operated by Boğaziçi University Kandilli Observatory and Earthquake Research In...

The Isparta Angle is an important area of SW Anatolia where extensions in all directions (N-S, NE-SW, NW-SE and E-W) meet. These extensions were determined by normal faulting structures as well as by shallow earthquakes. All extensions, except the E-W one, were attributed to the deviatoric stresses in relation to slab forces and/or extrusion of Ana...

KOERI (Kandilli Observatory and Earthquake Research Institute) operates a seismic network in Marmara Sea region (NW Turkey) consisting of 40 broadband, 30 strong motion and 3 borehole stations with sensors at different levels. The station distribution pattern is suitable for regional EEW studies. Moreover, 10 strong motion stations are distributed...

The main motivation for this study was the impending occurrence of a catastrophic earthquake along the Prince Island Fault (PIF) in the Marmara Sea and the disaster risk around the Marmara region, especially in Istanbul. This study provides the results of a physically based probabilistic seismic hazard analysis (PSHA) methodology, using broadband s...

Frequency distribution of azimuth and plunges of P- and T-axes of focal mechanisms is compared with the orientation of maximum compressive stress axis for investigating the frictional strength of three fault segments of North Anatolian fault (NAF) in eastern Marmara Sea, namely Princes’ Islands, Yalova–Çınarcık and Yalova–Hersek fault segments. In...

Monitoring the behavior of the structures is essential to identify changes in behavior and/or response of structures. It is also important that certain critical systems are safely shutdown during a potentially destructive earthquake. The objective of this study is to present the seismic monitoring and early warning systems set in the recently commi...

The feasibility of earthquake early warning (EEW) is now widely recognized. However, EEW systems that are in operation or under evaluation worldwide have significant variations and are usually operated independently of routine earthquake monitoring. We introduce a software that allows testing and evaluation of a well‐known EEW algorithm directly wi...

A novel approach is developed for estimating the near-surface attenuation using seismic noise recordings at a downhole array. The amplitude spectrum of the traffic-induced seismic noise at the engineering bedrock level exhibits a high-frequency decay between 10 and 40 Hz. Subsequently, it yields a Kappa value of 14 ± 3 ms and a quality factor of 45...

The faults' geometry and their seismic activity beneath the Marmara Sea have been under debate for a couple of decades. We used data recorded by three ocean bottom seismographs (OBSs) over a period of 3 months in 2014 to investigate the relationship of fault geometry to microseismicity under the western Marmara Sea in Turkey. We detected a seismic...

LESS-2015 Project has been recently completed with 100 km length seismic reflection data. We have observed seismically active reverse faults along the N-section of the lake. The S-section of the lake seems to be quiet and undeformed. The Lake bottom is considerably layered by very dense muddy deposits. The aftershock events greater than magnitude 4...

The Simav Earthquake that occurred on 19 May 2011 in western Turkey was investigated on the basis of seismological data and geological observations. Approximately WNW– ESE trending surface ruptures were observed on the Simav Fault. The focal mechanism parameters of the earthquake (Mw = 5.8) and its aftershocks (Mw > 3.5) were estimated using time-d...

The Simav Earthquake that occurred on 19 May 2011 in western Turkey was investigated on the basis of seismological data and geological observations. Approximately WNW– ESE trending surface ruptures were observed on the Simav Fault. The focal mechanism parameters of the earthquake (Mw = 5.8) and its aftershocks (Mw > 3.5) were estimated using time-d...

An international project network consisting of six receivers for sampling LF and VLF radio signals has been going on to record the data in Europe from different transmission stations around the World. One of them was established in Resadiye, Turkey, located just on the North Anatolian Fault Zone. The receiver works in VLF and LF bands monitoring te...

The main objective of this study is to simulate broad-frequency-band strong ground motion waveforms resulting from the rupture of the Prince Island Fault and to provide input accelerograms for linear and non-linear time history analyses for engineering structures. Simulations are performed using Green's Function methodology developed by Hutchings a...

The main objective of this study is to simulate broad-frequency-band strong ground motion waveforms resulted from the rupture of Prince Islands Fault, to provide input accelerograms for linear and non-linear time history analyses of the engineering structures. Simulations are performed using Green’s Function methodology developed by Hutchings and W...

Z Bu çalışmanın temel amacı, mühendislik yapılarının doğrusal ve doğrusal olmayan zaman ortamı analizlerine girdi verisi oluşturmak için, Prens Adaları Fayı'nın kırılmasıyla meydana gelmesi muhtemel büyük bir deprem sonrasında oluşacak yer hareketi dalga formlarını geniş bir frekans bant aralığında tahmin etmektir. Benzeşimlerin hesaplanmasında Hut...

The main purpose of this article is to simulate three mid-sized earthquakes that occurred in Marmara Sea region, which has complex geologic and tectonic characteristics resulting in heterogeneous crustal structure. In the calculation of earthquake simulations, the method based on empirical Green’s function (EGF) developed by Hutchings and Wu (1990)...

Bu makalenin temel amaci, jeolojik ve tektonik olarak karmasik ozellikler gosteren dolayisiyla oldukca heterojen bir kabuk yapisina sahip Marmara bolgesinde meydana gelmis uc adet orta buyuklukte depremin benzesimini elde etmektir. Deprem benzesimlerinin hesaplanmasinda Hutchings ve Wu (1990) tarafindan gelistirilen Ampirik Green Fonksiyon (AGF) ta...

The main purpose of this article is to simulate three mid-sized earthquakes that occurred in Marmara Sea region, which has complex geologic and tectonic characteristics resulting in heterogeneous crustal structure. In the calculation of earthquake simulations, the method based on empirical Green's function (EGF) developed by Hutchings and Wu (1990)...

The study area of the present research, the Van Region is located at the norththern end of the collision zone between the Anatolia and Arabian plates. Therefore, the southeast border of the Anatolian plate collides with the Arabian plate along the Bitlis Suture Zone. This zone is formed by collision of Arabian and in large scale Eurasian plates at...

Abstract—We analyzed the waveforms of the small- to moderate-sized earthquakes that took place in the northern part of the inner Isparta Angle (IA) to retrieve their source parameters and combine these results with the focal mechanism solutions of the larger events that occurred in 2007 in Egirdir Lake at the apex of IA. In total, source mechanisms...

The May 19, 2011 earthquake of which parameters are determined by different seismological centers with different size and depth (B.U.K.O.E.R.I. National Earthquake Observatory Centre Mw=5.7 (Ml=5.9) h=8 km; AFAD/ Earthquake Department Presidency Mw=5.8 (Ml=5.7) h=25 km; USGS Mw=5.8 h=7 km; IRIS Mw=6 h=4.6 km) occurred on the Simav Fault Zone (SFZ)...

Z: 19 Mayıs 2011 tarihinde Türkiye'nin batısında yer alan Ege Bölgesindeki Kütahya il sınırları içinde kalan Simav Fay Zonunda (SFZ) büyüklüğü ve derinliği farklı sismoloji merkezleri (KRDAE: Mw=5.7, Ml=5.9 h=8 km; AFAD: Mw=5.8, Ml=5.7 h=25 km; USGS Mw=5.8 h=7 km; IRIS (Incorporated Research Institutions for Seismology) Mw=6.0 h=4.6 km) tarafından...

We investigate the seismotectonic features resulting directly and indirectly from the interaction between the northeast moving African plate and the westward moving Anatolian block focusing mainly offshore and onshore of the region between the Fethiye Bay and the Gulf of Antalya. Our data is the broadband waveforms recorded at the seismic stations...

The October 23, 2011 Van-Ercis Earthquake (Eastern Turkey, Mw=7.2) and Characteris-tics of its Aftershocks The October 23, 2011 Van-Ercis Earthquake (Eastern Turkey, Mw=7.2) and Characteris-tics of its Aftershocks The intraplate Van-Ercis earthquake took place about 100 km to the north of a suture zone undergoing N-S shortening resulting from the o...