Source parameters for the M<Subscript>w</Subscript> = 6.6, 03 February 2002, Çay Earthquake (Turkey) and aftershocks from GPS,Southwestern Turkey

The 03 February 2002 Çay Earthquake (M_w ～6.7) occurred on the fault segment between Eber and Ak?ehir Lakes followed by a large aftershock (M_w ～5.6) near the western end of the fault and two sequential aftershocks. We computed the coseismic surface displacements from static GPS measurements to determine the fault geometry parameters and uniform slip components. The coseismic displacements were obtained through combining the regional pre-earthquake and post-earthquake GPS data. Fault geometry and slips were acquired through the inversion of GPS data modeling the events as elastic dislocations in a half-space and assuming all four events took place on the same fault plane. Results suggest that one-segment fault of ～33 km length and dipping ～43° northward suffices to model the dislocation, assuming uniform slip distribution with 0.51 m dip slip, 0.26 m left-lateral slip extending to a depth down to ～11.5 km which is consistent with seismological evidence. The results also verify the normal faulting in the eastern flank of Isparta Angle which has long been assumed as a thrusting structure. While the available data cannot identify the four individual events on the same day, an attempted distributed slip model differentiates dip slip and left-lateral slips near the hypocenter with maximum values of ～1 and 0.6 m, respectively.     

Site classification of Turkish national strong-motion stations

Since 1973, the General Directorate of Disaster Affairs of Turkey has deployed several strong-motion accelerographs at selected sites. Within the framework of the project entitled Compilation of National Strong Ground Motion Database in Accordance with International Standards, site conditions were investigated within the upper 30-m depth by surface seismic and standard penetration tests. Preliminary characterization of the sites is made by making use of both geophysical and geotechnical criteria of NEHRP Provisions and Eurocode-8 site classification systems. The liquefaction susceptibility of those sites which comprise saturated cohesionless deposits is also determined. Mean shear-wave velocity, mean penetration resistance, site class, and liquefaction susceptibility of each site are tabulated. The Turkish strong-motion database supplemented by detailed information on site conditions is a valuable source of information particularly for those studies that put emphasis on the relationship between site conditions and strong-motion parameters.     

Adaptive neuro-fuzzy modeling for the swelling potential of compacted soils

This paper aims to present the usability of an adaptive neuro fuzzy inference system (ANFIS) for the prediction swelling potential of the compacted soils that are important materials for geotechnical purposes such as engineered barriers for municipal solid waste, earth dams, embankment and roads. In this study the swelling potential that is also one of significant parameters for compacted soils was modeled by ANFIS. For the training and testing of ANFIS model, data sets were collected from the tests performed on compacted soils for different geotechnical application in Nigde. Four parameters such as coarse-grained fraction ratio (CG), fine-grained fraction ratio (FG), plasticity index (PI) and maximum dry density (MDD) were presented to ANFIS model as inputs. The results obtained from the ANFIS models were validated with the data sets which are not used for the training stage. The analyses revealed that the predictions from ANFIS model are in sufficient agreement with test results.     

The effect of seasonally frozen soil on stochastic response of elevated water tank under random excitation

Significant seismic events have occurred around the world during winter months in regions where cold temperatures cause ground freezing. Current seismic design practice does not address the effects of cold temperatures in the seasonally frozen areas. Since many elevated water tank structures in cold regions are located in seismic active zones, determining the effect of seasonally frozen soil on the stochastic response of elevated water tank structures subjected to random seismic excitation is an important structural consideration. A three dimensional finite element model, which considers viscous boundaries, was built up to obtain the stochastic seismic behavior of an elevated water tank–fluid–soil interaction system for frozen soil condition. For this model, the power spectral density function represents random ground motion applied to each support point of the three dimensional finite element model of the elevated water tank–fluid–soil interaction system. Numerical results show that the soil temperature affects the seismic response of the elevated water tank; whereas the variation in the thickness of the frozen soil causes insignificant changes on the response. In addition, the effect of the variation in water tank’s fullness on the stochastic response of the coupled system is investigated in the study. As a result, the seasonal frost changes the foundation soil stiffness and may impact seismic behavior of the water tank.     

Comparison of 2D versus 3D modeling approaches for the analysis of the concrete faced rock‐fill Cokal Dam

This paper's primary purpose is to compare the 2D and 3D analysis methodologies in investigating the performance of a concrete faced rock‐fill dams under dynamic loading conditions. The state of stress on the face plate was obtained in both cases using a total strain based crack model to predict the spreading of cracks on the plate and the corresponding crack widths. Results of the 2D and 3D analyses agree well. Although significantly more demanding, 3D analyses have the advantage of predicting the following: (i) the opening of the vertical construction joints; (ii) the cracking at the valley sides; and (iii) the crushing of the plate during the seismic action. During the earthquake loading, the cracking predicted at the base of the face plate after the impounding spread significantly towards the crest of the dam; however, the crack widths are obtained relatively small. Crushing of the face plates at the construction joints is the primary cause of the large scale cracking predicted on the face plate for high intensity earthquakes. Earthquake induced permanent deformation of the fill increases the compressive stresses on the face plate, thereby reducing the minute cracking on the plate. However, this effect also leads to significant increases in the residual openings at the construction joints and at the plinth level. Copyright © 2013 John Wiley & Sons, Ltd.     

Temporal dynamics of soil water balance components in a karst range in southeastern Spain: estimation of potential recharge

Abstract

This paper analyses the temporal dynamics of soil water balance components in a representative recharge area of the Sierra de Gádor (Almeria, southeastern Spain) in two hydrological years. Two approaches are used to estimate daily potential recharge (PR): Approach 1 based on deriving PR from the water balance as the difference between measurements of rainfall (P) and actual evapotranspiration (E) obtained by eddy covariance; and Approach 2 with PR obtained from the dynamic pattern of the soil moisture (θ) recorded at two depths in the site's thin soil (average 0.35 m thickess). For the hydrological year 2003/04, which was slightly drier than the 30-year average, E accounted for 64% of rainfall and occurred mainly in late spring and early summer. The PR estimated by Approach 1 was 181 ± 18 mm year^-1 (36% of rainfall), suggesting an effective groundwater recharge in the study area. In the unusually dry hydrological year 2004/05, E was about 215 mm year^-1, close to the annual rainfall input, and allowing very little (8 ± 12 mm year^-1) PR according to Approach 1. Estimation of PR based on Approach 2 resulted in PR rates lower than those found by Approach 1, because Approach 2 does not take into account the recharge that occurs through preferential flow pathways (cracks, joints and fissures) which were not monitored with the θ probes. Moreover, using Approach 2, the PR estimates differed widely depending on the time scale considered: with daily mean θ data, PR estimation was lower, especially in late spring, while θ data at 30 min resolution yielded a more reliable prediction of the fraction of total PR resulting from the downward movement of soil water by gravity.

Citation Cantón, Y., Villagarcía, L., Moro, M. J., Serrano-Ortíz, P., Were, A., Alcalá, F. J., Kowalski, A. S., Solé-Benet, A., Lázaro, R. & Domingo, F. (2010) Temporal dynamics of soil water balance components in a karst range in southeastern Spain: estimation of potential recharge. Hydrol. Sci. J. 55(5), 737–753.     

Laboratory experiments of sediment transport from bare soil with a rill

Abstract

Mathematical models developed for quantification of sediment transport in hydrological watersheds require data collected through field or laboratory experiments, but these are still very rare in the literature. This study aims to collect such data at the laboratory scale. To this end, a rainfall simulator equipped with nozzles to spray rainfall was constructed, together with an erosion flume that can be given longitudinal and lateral slopes. Eighty experiments were performed, considering microtopographical features by pre-forming a rill on the soil surface before the start of each experiment. Medium and fine sands were used as soil, and four rainfall intensities (45, 65, 85 and 105 mm h^-1) were applied in the experiments. Rainfall characteristics such as uniformity, granulometry, drop velocity and kinetic energy were evaluated; flow and sediment discharge data were collected and analysed. The analysis shows that the sediment transport rate is directly proportional to rainfall intensity and slope. In contrast, the volumetric sediment concentration stays constant and does not change with rainfall intensity unless the slope changes. These conclusions are restricted to the conditions of experiments performed under rainfall intensities between and 105 mm h^-1 for medium and fine sands in a 136-cm-wide, 650-cm-long and 17-cm-deep erosion flume with longitudinal and lateral slopes varying between 5 and 20%.

Editor Z.W. Kundzewicz; Associate editor G. Mahé

Citation Aksoy, H., Unal, N.E., Cokgor, S., Gedikli, A., Yoon, J., Koca, K., Inci, S.B., Eris, E., and Pak, G., 2013. Laboratory experiments of sediment transport from bare soil with a rill. Hydrological Sciences Journal, 58 (7), 1505–1518.     

Reliable Procedure for Molecular Analysis of Airborne Microflora in Three Indoor Environments: An Office and Two Different Museum Contexts

Biological aerosols from air constitute a significant source of exposure to microorganisms in public places. Airborne microorganisms are involved in the development of certain respiratory symptoms, allergies, or infections among users and occupants. Various sampling instruments have commonly been used in aerobiology to collect bacteria and fungi suspended in the air. The objective of this study was to develop a reliable procedure for sampling in indoor public environments presenting different levels of occupancy, airborne bacteria and fungi to be subjected to molecular analysis (bacteria and fungi quantitative PCR, capillary electrophoresis single strand conformation polymorphism fingerprinting). Four different sampling devices were tested in situ in an office building (open‐plan type) and the sampling strategy chosen was tested in two museum contexts. In accordance with the drawbacks involved to our study (quantitative and qualitative aspects, cost, and overcrowding), cyclone device appeared to be most suitable. The results underline the effectiveness of this high‐volume aerosol sampling device for both qualitative and quantitative molecular analysis. Four in situ sampling collections were carried out in 1 day in the Louvre Museum to study quantitative and qualitative variations of airborne bacterial and fungal diversity. The quantitative results revealed a similar order of magnitude for the numbers of both bacteria and fungi. In the Louvre Museum, the samples yielded between 3.7 × 10⁴ and 4.1 × 10⁴ genome equivalent (GE) bacteria/m³ air and between 5.0 × 10⁴ and 5.9 × 10⁴ GE fungi/m³ air and in the Decorative Arts Museum between, 2.1 × 10⁴ and 2.5 × 10⁴ GE bacteria/m³ air and between 1.4 × 10⁴ and 1.7 × 10⁴ GE fungi/m³ air. The results also indicate that the dominant bacterial community displayed a stable structure over a short period of time whereas dominant eukaryotic airborne community appeared more variable.