Intercontinental response to variations in the Arabia-Eurasia Plate convergence,calcite e-twin evidence of the Kuhbanan Fault system,Central Iran

Variations in the plate convergence direction have generally reflected on the kinematics of the major fault zones developed in the intercontinental parts of the collision zones. The Kuhbanan Fault system is one of the most important intercontinental faults in the Arabia-Eurasia collision zone with a dextral strike slip mechanism. This fault system is composed of three fault strands including Kuhbanan, Bazargan, and Kerman Faults. Here we used calcite e-twin analysis of the vein samples developed in these fault zones to reconstruct deformation condition and the paleodifferential stress direction and magnitude at the Kuhbanan Fault system. Our results represent 190°C-200°C of the deformation temperature and related 5–6 ± 1 km of deformation depth at the Kuhbanan Fault system. Calculated paleodifferential stress magnitude in the Kuhbanan Fault system using e-twin parameters ranges from 169-196 MPa similar to the inner parts of the orogenic systems. Comparing the data set of the Kuhbanan Fault system with previous studies at the Zagros orogen represents an increase of deformation depth and paleodifferential stress magnitudes from the foreland of the Zagros orogen to its hinterland and finally northward around the Kuhbanan Fault system in the central Iranian blocks. We have also proposed a shift of the stress direction from paleo NE to recent N directed by comparing paleostress direction deduced from the calcite e-twin and recent stress direction calculated from GPS and earthquake data analysis around the Kuhbanan Fault system. This kinematics change due to plate reorganization is in agreement with the observed regional variation in convergence direction all in the Arabia-Eurasia collision zone.     

Monitoring and projection of climate change impact on 24-h probable maximum precipitation in the Southeast of Caspian Sea

Natural Hazards - Due to the impacts of climate change on probable maximum precipitation (PMP) and its importance in designing hydraulic structures, PMP estimation is crucial. In this study, the...     

Land subsidence risk assessment using GIS fuzzy logic spatial modeling in Varamin aquifer,Iran

GeoJournal - The extent of the subsidence and the consequents damage to most of the residential and populated areas of Iran have made this phenomenon one of the most important natural hazards after...     

Ascribing soil erosion types for sediment yield using composite fingerprinting technique

Abstract

Soil erosion and eroded sediment are serious threats to sound land management. However, less attention has been given to quantifying the importance of different soil erosion features based on appropriate control measures that could be designated. Accordingly, this research was planned to quantify the contribution of potential sediment sources, i.e. sheet, rill and gully erosion, in Idelo watershed in Zanjan Province, Iran, using composite fingerprinting. Toward this aim, 16 geochemical and organic tracers were detected in sediment sources and sediment deposited at the outlet. The results of applying the composite fingerprinting technique, with a relative error of 16%, showed that sheet, rill and gully sources contributed 56%, 44% and 0%, respectively, to sediment yield. It was also apparent from the results that the composite fingerprinting approach could be successfully utilized to assess the provenance of sediment deposited at the main outlet of the study watershed by soil erosion type.

Editor Z.W. Kundzewicz     

Multiple linear regression,multi-layer perceptron network and adaptive neuro-fuzzy inference system for forecasting precipitation based on large-scale climate signals

ABSTRACT

Nowadays, mathematical models are widely used to predict climate processes, but little has been done to compare the models. In this study, multiple linear regression (MLR), multi-layer perceptron (MLP) network and adaptive neuro-fuzzy inference system (ANFIS) models were compared for precipitation forecasting. The large-scale climate signals were considered as inputs to the applied models. After selecting the most effective climate indices, the effects of large-scale climate signals on the seasonal standardized precipitation index (SPI) of the Maharlu-Bakhtaran catchment, Iran, simultaneously and with a delay, was analysed using a cross-correlation function. Hence, the SPI time series was forecasted up to four time intervals using MLR, MLP and ANFIS. The results showed that most of the indices were significant with SPI of different lag times. Comparison of the SPI forecast results by MLR, MLP and ANFIS models showed better performance for the MLP network than the other two models (RMSE = 0.86, MAE = 0.74 for the first step ahead of SPI forecasting).

Editor D. Koutsoyiannis; Associate editor F. Pappenberger     

Dynamic earth pressure on rigid retaining walls induced by a neighboring machine foundation,by the meshless local Petrov-Galerkin method

Dynamic earth pressure induced by machine foundations on a neighboring retaining wall is analyzed with emphasis on factors which control the intensity and location of the design forces. The meshless local Petrov-Galerkin(MLPG) method is used to analyze the problem for a variety of retaining wall and machine foundation geometries. The soil medium is assumed to be homogeneous and visco-elastic. The machine foundation is idealized as a harmonic sinusoidal dynamic force often encountered in practice. A number of analyses have been made to reveal the effect of the loading frequency, the location and size of the foundation and the soil shear wave velocity on the distribution and magnitude of the dynamic earth pressure. Results indicate that there is a critical frequency and a critical location for which the passive pressure takes the maxima in the entire duration of the dynamic load.     

Neural network prediction of solar cycle 24

The ability to predict the future behavior of solar activity has become extremely import due to its effect on the environment near the Earth.Predictions of both the amplitude and timing of the next solar cycle will assist in estimating the various consequences of space weather.The level of solar activity is usually expressed by international sunspot number (Rz).Several prediction techniques have been applied and have achieved varying degrees of success in the domain of solar activity prediction.We predict a...