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Active tectonic and paleoseismologic characteristics of the Yenice-Gönen fault, NW Turkey, in light of the 18 March 1953 Yenice-Gönen Earthquake (Ms=7.2)
BULLETIN OF THE MINERAL RESEARCH AND EXPLORATION (MTA Dergisi)
Article Details
Active tectonic and paleoseismologic characteristics of the Yenice-Gönen fault, NW Turkey, in light of the 18 March 1953 Yenice-Gönen Earthquake (Ms=7.2)
The Yenice-Gönen Fault (YGF) is located in the central part of the Biga Peninsula between Gönen and Yenice and is a right-lateral strike-slip active fault with general trending N65°E. On 18 March 1953 there was an earthquake on the YGF that died 263 people (Ms=7.2) and a 70 km surface rupture developed during this earthquake. In this study measurements of slip distribution were performed on the surface rupture of the Yenice-Gönen Earthquake (YGE) and the annual slip rate on the YGF was calculated. Right-lateral displacements of between 1.70±0.1 and 3.20±0.2 metres were measured on the surface rupture of the YGE. The maximum displacements were in an area close to the central part of the YGF (between Çakır and Karaköy village) and these values decreased relatively in NE and SW directions, documenting that was the bilaterally surface rupture propogation during the YGE. In the last 300.000 years, a total offset of 800±50 metres was measured on Gönen River and annual slip rate of 2.65±0.15 mm was calculated along the YGF. Current GPS studies show right-lateral strike-slip faults in the South Marmara region have slip rates of 6-8 mm/year. This slip rate is assessed as being partitioned between the YGF, Sarıköy Fault and Çan-Biga Fault zones which represent extensions of the North Anatolian Fault system within the South Marmara region. Paleoseismology studies determined that in the last 6200 years 6 earthquakes resulting in surface ruptures have occurred on the YGF, including the 1953 earthquake. According to the 14C and OSL dating results, the variable and irregular earthquake recurrence interval of YGF is ranging from 505 to 1793 years. In this study average earthquake recurrence interval of YGF was determined as 1180 years.
Structural Geology, Active tectonics · Volume 172 / December 2023 · Pages: 119-140
Ali KOÇYİĞİT
Indexed In · Volume 172 / December 2023
Neotectonics of the Sarıköy-İnova and Çan-Bayramiç-Ezine fault zones: basin formation, age and slip rates, NW Anatolia-Türkiye
Authors:
Ali KOÇYİĞİT
ABSTRACT
The Sarıköy-İnova and the Çan-Bayramiç-Ezine fault zones (SIFZ, ÇBEFZ) comprise the southern strand of the North Anatolian Fault System in the Biga Peninsula. They are located in the area between Sarıköy to northeast and the Dalyan settlement around Bozcaada in the North Aegean Sea to southwest. Both of the fault zones are active. This is evidenced by the 6 March 1737 (Ms =7.0) İnova, 1st February 1809 Hurma (Ms = 6.1), and the 8 February 1826 Güllüce (Ms = 6.2) historical earthquakes resulted from these fault zones. Maximum lengths of fault segments comprising the SIFZ and the ÇBEFZ are 14 km and 15 km, respectively. Based on the maximum lengths of fault segments, the magnitude of the peak earthquakes to be originated from these faults are Mw = 6.3 and 6.6, respectively. Based on both the geological and geographic markers, the total right lateral offsets accumulated on the SIFZ and ÇBEFZ are 12 km and 20 km, respectively. These offset values imply to the slip rates of 4.6 mm/yr and 7.7 mm/yr, respectively. Five pull-apart basins were developed on both fault zones. These are the Sarıköy, İnova, Kazabat, Çan and Ezine-Bayramiç basins. The first three of them are pure strike-slip pull-apart basins, while the type of the rest basins is superimposed. The angular unconformity between the nondeformed basin fill of Quaternary age and the folded to thrust-faulted basement rocks of pre-Quaternary age reveals strongly that the pull-apart basins have formed during the Quaternary time. This relationship also reveals that the commencement age of the strike-slip neotectonic regime and formation of associated fault zones are the Early Quaternary. This work was dedicated to the retirement memory of Dr. Fuat Şaroğlu.
Şule GÜRBOĞA, Aslı Zeynep YAVUZOĞLU, Recep GÜNEY, Fatma BETÜL KARCI, Ayhan YAVUZOĞLU, Özgür TÜRKMEN, Pir Çağatay KARTAL, Bahri Serkan AYDEMİR, Murat EVREN, Murat CENK, Barbaros ŞİMŞEK, Eyyüp ÖZBEK, Tuğrul Şükrü YURTSEVER, Füsun YİĞİT FETHİ, Eşref AYLAN, Uğur Zeki KIRAT
Indexed In · Volume 163 / 2020
Tectonic meaning of the deformation in shallow marine region between Gaziköy-Mürefte (Sea of Marmara) by using seismic reflection data, NW Anatolia
Authors:
Şule GÜRBOĞA, Aslı Zeynep YAVUZOĞLU, Recep GÜNEY, Fatma BETÜL KARCI, Ayhan YAVUZOĞLU, Özgür TÜRKMEN, Pir Çağatay KARTAL, Bahri Serkan AYDEMİR, Murat EVREN, Murat CENK, Barbaros ŞİMŞEK, Eyyüp ÖZBEK, Tuğrul Şükrü YURTSEVER, Füsun YİĞİT FETHİ, Eşref AYLAN, Uğur Zeki KIRAT
ABSTRACT
Within the scope of this paper, seismic reflection and bathymetry studies were carried out in the shallow marine area forming the westernmost part of the Tekirdağ Basin using the R/V Selen Research Vessel within the MTA Marine Research Department. In the study area, ~ 500 km length bathymetry data and ~191 km shallow seismic profiles ( 41 lines) were collected. By means of the data, tectonic structures and deformation textures of the North Anatolian Fault System (NAFS) in the marine area of Gaziköy were examined. As a result of the processing and interpretation of the seismic sections, compression structures occurring due to the SW rotation of the NAFS in the study area, the morphology of the Ganos depression that formed as a result of faulting and also three different stratigraphic units were distinguished. These units are separated from each other by distinct unconformity surfaces and each unit presents different deformation structures. One of the most significant results obtained from the seismic data is that the unconformity surface that separates the current sediments of the seafloor from the older units is represented by the overlapping structures indicate sea level changes. It has been assessed that this situation occurred as a result of the erosional process developed during sea level fall.
https://doi.org/10.19111/bulletinofmre.784476
Keywords:
Gaziköy-Mürefte, Shallow marine deformation, Unconformity surface, North Anatolian Fault System, Sea of Marmara.
Early–middle Miocene reefal limestones are overlain disconformably by late Serravallian– early Tortonian incised valley-fi ll deposits of Dağpazarı formation in the Mut Basin. Dağpazarı formation is composed of mudstone, siltstone, sandstone and conglomerates. Facies associations of the formation are: fl uvial, lagoon, shoal-water delta, shoreface, beach and barrier island deposits. Loxoconcha tumida Brady and Loxoconcha sp. in the gray mudstones indicate the freshwater infl uence and decrease in salinity. Hemicyprideis sp. documents brackish water conditions. The shoreface sandstones alternating with the lagoonal mudstones, and oyster-rich beach deposits in different levels of the sequence indicate episodes of marine connections. The age of the Dağpazarı formation is provided by the planktonic foraminifera from the marine mudstones and marls below and above the formation, and corresponds to the MMi8–MMi10 biostratigraphic interval, which spans the late Serravallian–early Tortonian. Late Serravallian eustatic sea-level fall caused to the quick shallowing of the Mut Basin and subaerial exposure of the reefal limestones at the basin margin. Thus, the incised valley, formed upon the reefal limestones of the Mut formation. This incised valley refl ects a regional forced regression and unconformity. The Dağpazarı formation was deposited within this incised valley following an early Tortonian relative sea-level rise.
https://doi.org/10.19111/bulletinofmre.501543
Theophilus Aanuoluwa ADAGUNODO, Lukman Ayobami SUNMONU, Moruffdeen Adedapo ADABANIJA, Maxwell OMEJE, Oluwole Akinwumi ODETUNMIBI, Victor IJEH
Indexed In · Volume 159 / 2019
Statistical assessment of radiation exposure risks of farmers in Odo Oba, Southwestern Nigeria
Authors:
Theophilus Aanuoluwa ADAGUNODO, Lukman Ayobami SUNMONU, Moruffdeen Adedapo ADABANIJA, Maxwell OMEJE, Oluwole Akinwumi ODETUNMIBI, Victor IJEH
ABSTRACT
The toxicity risks of being over exposed to ionizing radiation in the environments are of great concern to environmental and health scientists. The distribution of radioactivity concentrations of thorium, uranium and potassium were studied in randomly selected soil samples from ten (10) farm locations in Odo Oba, southwestern Nigeria in order to determine the radiological risks of farmers’ exposure to radionuclides. The mean estimation of thorium and potassium are greater than the global average by factors of 1,5 and 2,7, while that of uranium fall below the global average. The estimation of radioactivity ratios showed a depletion of uranium and enrichment of thorium in the study area. Further analysis on the radioelements (that is, thorium, uranium and potassium) showed that 83% of the estimated radiological risks are above the global average. The multivariate analyses involving Pearson’s correlation, Factor Analysis, Hierarchical Cluster Analysis were also used to explain the correlations among the data sets. It was affirmed from the multivariate analysis that the radiological hazards occur as a result of contributions from the three naturally occurring radionuclides. The values obtained in this study revealed that the sampled locations are contaminated zones for farmers.
https://doi.org/10.19111/bulletinofmre.495321
A brief note on the effects of floating standard deviation (non- derivative) and horizontal gradient (derivative) filters
Authors:
Ceyhan Ertan TOKER
ABSTRACT
When processing gravity data, the filters are used in space and frequency environments. The filters allow more selectable parameter estimations than raw data about the structure being examined. Filtering in a broad sense means monitoring the data under the constraints we want. While the filters allow some information to become more noticeable, they allow some information to be lost or become less noticeable from data. In this case, the losses in the data make the interpretation difficult and can cause errors. Derivative and phase filters provide quantitative information about the variation of data in different directions. The display of the change results in a positive or negative manner proportional to derivative sensitivity and phase sharpness, and this may be observed in this data. In the structural boundary analysis, since the sudden changes in the derivative cause oscillations, the boundaries become questionable. Limiting the data neighborhoods with a window by controlling the deviation without using derivative and the filters that allow boundary analysis non-derivative by floating this limitation are used to illuminate the boundary relationships.
https://doi.org/10.19111/bulletinofmre.546153
Keywords:
Gravity, Filter, Standard deviation, Long wavelength, Nonderivatives.
