Petrogenesis of plio-quaternary intra-plate continental alkaline lavas from the İskenderun Gulf (Southern Turkey): Evidence for metasomatized lithospheric mantle     

Aykut Güçtekin 《Chemie der Erde / Geochemistry》2018,78(4):521-534

The Quaternary alkaline volcanic field of Southern Turkey is characterized by intra-continental plate-type magmatic products, exposed to the north of the ?skenderun Gulf along a NE-SW trending East Anatolian Fault, to the west of its intersection with the N–S trending Dead Sea Fault zone. The ?skenderun Gulf alkaline rocks are mostly silica-undersaturated with normative nepheline and olivine and are mostly classified as basanites and alkaline basalts with their low-silica contents ranging between 43 and 48?wt.% SiO₂. They display Ocean Island Basalt (OIB)–type trace element patterns characterized by enrichments in large-ion-lithophile elements (LILE) and light rare earth element (LREE), and have (La/Yb)_N?=?8.8–17.7 and (Hf/Sm)_N?=?0.9–1.6 similar to those of basaltic rocks found in intraplate suites. The basanitic rocks have limited variations Sr-Nd isotopic ratios (⁸⁷Sr/⁸⁶Sr?=?0.70307–0.70324, ¹⁴³Nd/¹⁴⁴Nd?=?0.512918–0.521947), whereas the alkali basalts display more evolved Sr-Nd isotopic ratios (⁸⁷Sr/⁸⁶Sr?=?0.70346-0.70365, ¹⁴³Nd/¹⁴⁴Nd?=?0.512887–0.521896). The ?skenderun Gulf alkaline rocks also display limited Pb isotopic variations with ²⁰⁶Pb/²⁰⁴Pb?=?18.75–19.09 ²⁰⁷Pb/²⁰⁴Pb?=?15.61–15.66 and²⁰⁸Pb/²⁰⁴Pb?=?38.65–39.02, indicating that they originated from an enriched lithospheric mantle source. Calculated fractionation vectors indicate that clinopyroxene and olivine are the main fractionating mineral phases. Similarly, based on Sr-Nd isotopic ratios, the assimilation and fractional crystallization (AFC) modeling shows that the alkali basalts were affected by AFC processes (r?=?0.2) and were slightly contaminated by the upper crustal material.The high TiO₂ contents, enrichments in Ba and Nb, and depletions in Rb can likely be explained by the existence of amphibole in the mantle source, which might, in turn, indicate that the source mantle has been affected by metasomatic processes. The modeling based on relative abundances of trace elements suggests involvement of amphibole-bearing peridotite as the source material. ?skenderun Gulf alkaline rocks can thus be interpreted as the products of variable extent of mixing between melts from both amphibole-bearing peridotite and dry peridotite.  相似文献   

A new approach to minimize the loss of life after natural hazards by using Android operating system     

Avuçlu  Emre  Başçiftçi  Fatih 《Natural Hazards》2018,90(2):1005-1016

Nowadays, the usage rates of smartphones are increasing rapidly. With the versatility of its features, smartphones have succeeded in attracting users. Performing this study has also affected the usage rate of smartphones every day. It is possible to determine the position with GPS (Global Positioning System) technology which is located in smartphones. In this study, smartphone location notification was used to detect the locations of the people who were under debris after the earthquake by means of the phones on them. People who cannot be reached for any reason will be immediately identified, and emergency interventions will be possible. Thus, the survival rate of the injured will be high with early intervention. In this study, it was aimed to minimize the loss of life after the earthquake and all the negativities that would be experienced in society due to this loss. The developed application has been tested in the external world, and the obtained data are given in results section.

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Assessing the performance of WRF model in predicting high-impact weather conditions over Central and Western Africa: an ensemble-based approach     

Igri  P. Moudi  Tanessong  Roméo S.  Vondou  D. A.  Panda  Jagabandhu  Garba  Adamou  Mkankam  F. Kamga  Kamga  A. 《Natural Hazards》2018,93(3):1565-1587

Natural Hazards - For numerical weather prediction over a particular region, it is important to know the best combination of physical parameterizations available in the considered modelling frame...  相似文献   

Image-aided platform orientation determination with a GNSS/low-cost IMU system using robust-adaptive Kalman filter     

Wenlin Yan  Luísa Bastos  José A. Gonçalves  Américo Magalhães  Tianhe Xu 《GPS Solutions》2018,22(1):12

The availability of miniaturized sensors with enhanced capabilities, new methods for image processing, and easy access to small and low-weight airborne platforms for data acquisition, including unmanned vehicles, opens new possibilities for geodetic navigation applications and developing new developments in sensor fusion. In this context, the development of efficient methods, based on low-cost sensors, to extract precise georeferenced information from digital cameras is of utmost interest. We present a method to improve the performance of the integration of GNSS/low-cost IMU by exploiting the orientation changes retrieved from digital images. In this work, a robust-adaptive Kalman filter is also introduced to further improve the performance of the method deployed. The adaptive factor and the robust factor accomplished are determined by innovation information and the threshold value of orientation changes between consecutive images. Results from airborne tests used to assess the performance of the method are presented. The results show that using a non-metric camera, the Euler angle estimation accuracy of the GNSS/low-cost IMU integration can be improved to be close to 0.5 degree and an additional improvement, which can reach 59%, can be achieved after using the robust-adaptive Kalman filter.  相似文献   

The investigation of flood risk perception as a quantitative analysis from socio-demographic perspective     

Eryılmaz Türkkan  Gökçen  Hırca  Tuğçe 《Natural Hazards》2021,106(1):715-733

The priority of flood management planning is physical victimization and focuses on taking structural measures. Although this approach is an accurate approach, more information is needed in implementing efficient precautionary and planning decisions. It is an indisputable fact that the existence of nothing that is not sustainable in nature cannot continue. Hence, it is necessary to implement a planning decision suitable for the structure of the population living in the region so that the continuity of the policies to be carried out against natural hazards of hydrometeorological origin such as a flood is ensured. How the socio-demographic structures affect the flood risk perception of 245 people living in the city center of Bayburt is examined in this study. It is the first research conducted for the province of Bayburt for this perspective. The participants were asked to fill a questionnaire containing 24 items and consisting of 2 sections. T test and one-way ANOVA (one-way analysis of variance) statistical methods were used to ascertain the difference between the responses of the participants to the questionnaire, based on their demographic structure. As the result of the study, significant differences were observed between the expressions depicting flood risk perception and the participant's age, income levels and educational background. In addition, it has been noted that there is a positive relationship between education and income levels and flood risk perception.

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Hydrologic models coupled with 2D hydrodynamic model for high-resolution urban flood simulation     

de Arruda Gomes  Mayara Maria  de Melo Verçosa  Lívia Fragoso  Cirilo  José Almir 《Natural Hazards》2021,108(3):3121-3157

Natural Hazards - Floods are the most frequent natural disaster and pose a very challenging threat to many cities worldwide. Understanding the flood dynamic is essential for developing strategies...  相似文献   

The Colider and Roosevelt Volcanic rocks (sw amazonian craton): geochemistry and sm-nd isotope characteristics of a silicic large igneous province     

Saar de Almeida  Bruna  Geraldes  Mauro César  Sommer  Carlos Augusto  Corrales  Felipe  de Barros  Antonio João Paes 《中国地球化学学报》2021,40(6):1023-1049

The volcanic rocks of the Colíder and Roosevelt formations are extensively exposed in the south-central portion of the Amazonian Craton where effusive and pyroclastic rocks have been mapped. Both units, topped by chemical sediments and oceanic facies as rhyolite and andesite lavas, rhyodacite, and porphyritic dacite, with frequent intercalations of pyroclastic and epiclastic deposits. Whole-rock geochemistry for 55 samples of rhyolitic to andesitic composition suggests the involvement of fertile mantle-derived components with E-MORB to OIB compositions. The analyzed rocks display calc-alkaline to shoshonitic affinity consistent with generation related to an active continental margin. The whole-rock Sm-Nd isotope data from selected felsic volcanic rocks of the Colíder and Roosevelt formations yield negative initial ε_Nd values between –3 and –9, indicating the predominantly crustal nature of the parental magmas with early Archean to late Paleoproterozoic (ca. 2.5–2.0 Ga) depleted mantle model ages.

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Groundwater metering: revisiting a ubiquitous ‘best practice’     

Molle  François  Closas  Alvar 《Hydrogeology Journal》2021,29(5):1857-1870

Hydrogeology Journal - It is often taken for granted that metering is an unarguable ‘best practice’ when it comes to the quantitative management of groundwater resources. This paper...  相似文献   

The effect of cement material properties on the fracture patterns developing within cement-covered brittle sphere under impact     

Jiang  Sheng  Shen  Luming  Guillard  François  Einav  Itai 《Acta Geotechnica》2021,16(3):763-773

Acta Geotechnica - Dynamic loading experiments of single glass bead cement-covered by epoxy resins of different compositions demonstrate the existence of diverse fracture patterns under similar...  相似文献   

Single-particle crushing strength under different relative humidity conditions     

Manso  João  Marcelino  João  Caldeira  Laura 《Acta Geotechnica》2021,16(3):749-761

This paper presents a fundamental study on the effect of the relative humidity on the rockfill crushing strength. This aspect plays an important role in the mechanical behaviour of rockfill, and it is known that certain characteristics of the granular materials, such as compressibility and shear strength, depend on the confining stress, which is a function of the particles crushing. An increased interest has been observed regarding the effect of the relative humidity in the mechanical behaviour of rockfill. Unfortunately, limited research has been conducted until now regarding the study of individual particle crushing. Therefore, this paper thoroughly investigated particle crushing, by performing single-particle crushing tests on rockfill particles divided into four size ranges, under different relative humidity conditions. The experimental results reveal a considerable influence of the relative humidity in the studied rockfill particles, whose strength of the particles with the greatest dimensions in saturated conditions was reduced by half. Consistent macro-mechanical evidence demonstrates that particle’s size and relative humidity conditions depict the most important factors that influence particle crushing strength.

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