Potential sea-level rise effects on the hydrodynamics and transport processes in Hudson–Raritan Estuary,NY–NJ

Ocean Dynamics - The climatic change has led to the sea-level rise (SLR), which is expected to continue based on the current industrial and human activities. Previous studies indicated that most of...     

Tsunami coastal hazard along the US East Coast from coseismic sources in the Açores convergence zone and the Caribbean arc areas

Natural Hazards - Tsunami coastal hazard is modeled along the US East Coast (USEC), at a coarse regional (450 m) resolution, from coseismic sources located in the Açores Convergence Zone (ACZ)...     

Zircon U–Pb geochronology,major-trace elements and Sr–Nd isotope geochemistry of Mashhad granodiorites (NE Iran) and their mafic microgranular enclaves: evidence for magma mixing and mingling

ABSTRACT

Mashhad granitoids and associated mafic microgranular enclaves (MMEs), in NE Iran record late early Mesozoic magmatism, was related to the Palaeo-Tethys closure and Iran-Eurasia collision. These represent ideal rocks to explore magmatic processes associated with Late Triassic closure of the Palaeo-Tethyan ocean and post-collisional magmatism. In this study, new geochronological data, whole-rock geochemistry, and Sr–Nd isotope data are presented for Mashhad granitoids and MMEs. LA–ICP–MS U–Pb dating of zircon yields crystallization ages of 205.0 ± 1.3 Ma for the MMEs, indicating their formation during the Late Triassic. This age is similar to the host granitoids. Our results including the major and trace elements discrimination diagrams, in combination with field and petrographic observations (such as ellipsoidal MMEs with feldspar megacrysts, disequilibrium textures of plagioclase), as well as mineral chemistry, suggest that MMEs formed by mixing of mafic and felsic magmas. The host granodiorite is a felsic, high K calc-alkaline I-type granitoid, with SiO₂ = 67.5–69.4 wt%, high K₂O (2.4–4.2 wt%), and low Mg# (42.5–50.5). Normalized abundances of LREEs and LILEs are enriched relative to HREEs and HFSEs (e.g. Nb, Ti). Negative values of whole-rock εNd_(t) (?3 to ?2.3) from granitoids indicate that the precursor magma was generated by partial melting of enriched lithospheric mantle with some contributions from old lower continental crust. In the MMEs, SiO₂ (53.4–58.2 wt%) is lower and Ni (3.9–49.7 ppm), Cr (0.8–93.9 ppm), Mg# (42.81–62.84), and εNd_(t) (?2.3 to +1.4) are higher than those in the host granodiorite, suggesting a greater contribution of mantle-derived mafic melts in the genesis of MMEs.     

Experimental investigating on the reflected waves from the caisson-type vertical porous seawalls

The hydrodynamic efficiencies of caisson-type vertical porous seawalls used for protecting coastal areas were calculated in this study. Physical models were developed to compare the wave reflection from vertical plane, semi-porous, and porous seawalls caused by both regular and random waves. Tests were carried out for a wide range of wave heights, wave periods, and different water depths (d=0.165, 0.270 and 0.375 m). The performance regarding the reflected waves from porous and semi-porous seawalls showed improvement when compared with those from the plane seawall. The reflection coefficients of the porous and semi-porous seawalls were calculated as 0.6 and 0.75, respectively, while the coefficient for the fully reflecting plane vertical wall was significantly higher (0.9). It was also observed that the reflection coefficient decreases with increase in wave steepness and relative water depth. In addition, the reduction in the reflection coefficient of porous and semi-porous seawalls, as compared to that of a plane seawall, was observed for both regular and random waves. New equations were also proposed to calculate the reflection coefficient of different types of seawalls with the aid of laboratory experiments. By verifying the developed equations using some other experimental data, it was validated that the equations could be used for practical situations. The results of the present study can be applied to optimize the design of vertical seawalls and for coastal protecting schemes.     

Evaluation of relative tectonic activity of Buin Zahra-Avaj area,northern Iran

Present active tectonics is affecting central Alborz and created various dynamic landforms in Buin Zahra-Avaj area, northern Iran. The area, located between the southern central Alborz and the edge of northwestern central Iran, is the result of both the Arabian–Eurasian convergence and clockwise rotation of the south Caspian Basin with respect to Eurasia in which most of the steep fault planes have a left lateral strike-slip component and most of the dip-slip faults are reverse, dipping SW. Since this region consists of several residential and industrial areas and includes several fault zones, the assessment of the structures of the present activity is vital. Six significant morphometric indices have been applied for this evaluation including stream length–gradient (SL), drainage basin asymmetry factor (Af), hypsometric integral (Hi), ratio of valley floor width to valley height (Vf), drainage basin shape (Bs), and mountain front sinuosity (Smf). The combined analyzed indices, represented through the relative tectonic activity (Iat), were used. The study area was divided into four regions according to the values of Iat. These classes include class 1 (very high activity,18%), class 2 (high, 20%), class 3 (moderate, 44%), and class 4 (low, 18%). The results of these indices are consistent with field observations on landforms and the deformation of Quaternary deposits.     

Geospatial technologies for detection and monitoring of Ganoderma basal stem rot infection in oil palm plantations: a review on sensors and techniques

Basal stem rot (BSR) is a type of disease that induces oil palm death within a short span of the appearance of symptoms. BSR early detection would facilitate to curb this by adopting appropriate strategies. In this paper, a systematic review was undertaken to demonstrate the need for authentic health condition monitoring of oil palm plantations. The currently used remotely sensed (RS) techniques for BSR detection and classification were reviewed. Several kinds of RS techniques were exerted for BSR detection and its severity classification up to four levels. It was identified that applied geospatial technologies, including multispectral and hyperspectral remote sensing, terrestrial laser scanning, spatial maps, tomography images, intelligent e-nose and Microfocus X-ray fluorescence, were capable of distinguishing infected oil palms from the non-infected ones. Furthermore, some of them are able to categorize BSR severity level up to four levels as well as of its early detection.     

Spatial prediction of soil erosion susceptibility: an evaluation of the maximum entropy model

Soil erosion is considered as the most widespread form of soil degradation which causes serious environmental problems. This study investigates the performance of the maximum entropy (ME) in mapping rill erosion susceptibility in the Golgol watershed, Ilam province, Iran. To this end, ten rill erosion conditioning factors were selected to be employed in the modelling process based on an investigation of the literature. These layers are: elevation, slope percent, aspect, stream power index, topographic wetness index, distance from streams, plan curvature, lithology, land use, and soil. Then, a training dataset of rill erosion locations was used for modelling this phenomenon. The area under receiver operating characteristics curve was used for evaluating the performance of the ME model. In addition, Modified Pacific South-West Inter Agency Committee (MPSIAC) framework was applied and sediment yield was determined for different hydrological units in the study area. At last, Jackknife test was implemented to show the contribution of the factors in the modelling process. The results depicted that area under ROC curve for training and validation datasets were 0.867, and 0.794, respectively. Therefore, this conclusion can be achieved that ME worked well and could be a good tool for generating rill erosion susceptibility maps and its output could be employed for soil conservation in similar areas.     

Removal of acetaminophen from hospital wastewater using electro-Fenton process

The current work deals with efficient removal of acetaminophen (AC) from hospital wastewater using electro-Fenton (EF) process. The degradation yield of 99.5% was obtained under optimal experimental conditions, namely 5.75 mg L^?1 initial AC concentration, 2.75 pH solution, 3-cm inter-electrode distance, 100 mg L^?1 KCl electrolyte, 122.5 µL L^?1 H₂O₂, 8 mA cm^?2 current density at equilibrium time of 8 min. Analysis of variance (ANOVA) suggested that the effect of mentioned operating parameters was statistically significant on the AC removal. The low probability amount of P value (P < 0.0001), the Fisher’s F-value of 65.91, and correlation coefficient of the model (R² = 0.9545) revealed a satisfactory correlation between the experimental and the predicted values of AC removal. The predicted removal efficiency of 99.4% was in satisfactory agreement with the obtained experimental removal efficiency of 98.7%. The AC degradation during the EF followed a first-order kinetic model with rate constants (K_app) of 0.6718 min^?1. Using the ordinary radical scavengers revealed that main mechanism of AC degradation controlled by the hydroxyl free radicals produced throughout the EF process. The excess amount of iron (II) scavenged the active radicals and diminished the concentration of ^·OH available to react with AC. The optimum molar ratio of H₂O₂ to Fe²⁺ was found to be 2.5. The developed EF process as a promising technique applied for treatment of real samples.     

Statistical modeling the effect of sediment physicochemical properties on the concentration of heavy metal (case study: Musa Creek,SW Iran)

Heavy metal accumulation in sediments is important even at low levels due to their irresolvable character and harmful effects. Therefore, contamination of creeks, especially their sediments, is highly important for scientific communities. This study investigates the relationship between heavy metal accumulation and some physicochemical parameters of sediments (pH, EC, calcium carbonate, texture, specific gravity, density, porosity and percentage of organic matter) in a stretch of Musa Creek beaches. The results showed that the studied sediments are extremely salty and have slight variations in terms of pH. Although there are mostly clay-sized sediments in the studied area, their mineralogical composition contains calcite with smaller amounts of dolomite, aragonite and halite minerals. The correlation between each of the parameters and heavy metal concentration was modeled using OLS regression. Cr, Ni, Zn and Pb concentrations are positively correlated with each other and inversely correlated with Cd. The accumulation of heavy metals is directly related to parameters such as EC, organic matter, clay and silt, specific gravity and porosity; it is negatively related to calcium carbonate, sand and density parameters. Owing to slight variations, the pH parameter lacks any significant correlation with heavy metal concentrations.     

Tectonic observations in the northern Saih Hatat,Sultanate of Oman

The Saih Hatat region, in northeastern Oman, is characterized by a large tectonic window, tectonically overlain during the upper Cretaceous by nappes composed of sedimentary rocks from the Mesozoic Hawasina ocean and the Samail ophiolite. In this window, the autochthonous sedimentary cover of the eastern Arabian Platform from the Late Neoproterozoic to the Cenomanian is well exposed. The oldest of these strata, the Hatat schists, were deformed into a NE-facing fold nappe during the upper Cretaceous. Within the overturned and thrusted lower limb of that fold nappe, we identified three small windows exposing stratigraphically younger Hiyam carbonates and Ordovician sandstone. The structural inventory of the windows and the surrounding area indicates three major tectonic phases. The first deformation led to NNE-SSW trending fold structures which probably formed simultaneously with the major fold nappe of the Hatat schists, followed by the extreme attenuation and thrusting of the lower limb of the fold nappe. The second phase was a gentle folding of the thrust with N-S oriented fold axes and third deformation phase that formed WNW-ESE oriented open folds. The windows are situated in the intersection of anticline axes of these two superposed fold generations and represent a mini basin-and-dome structure with an extension of just 1 km?×?1 km.