Iodine concentrations of soils near Trabzon, Turkey: a region of endemic goiter

Iodine contents of soils developed over the major rock formations of the northern zone of the Eastern Pontide Tectonic Belt (Northeastern Turkey) have been investigated with respect to soil-parent rock relationship, effect of topography, elevation, and climate to construe its effect on the health of the local population. Samples were collected from the A and B horizons of the soils developed over the major stratigraphic units constituting the eastern Pontides, including the Lower Basic Complex of Jurassic-Lower Cretaceous age, the Berdiga limestone (Jurassic-lower Cretaceous), the Dagbasi granitoid (Upper Cretaceous), volcano-sedimentary sequence of Upper Cretaceous age, ore-bearing and barren dacites of Upper Cretaceous age, and Neogene alkaline basalts. Chemical analyses of soil samples indicate significantly lower iodine abundances for all the soils studied (5–28 ppm) in comparison to the average abundance of iodine in analogous soils of other parts of the world (22–93 ppm). The concentration of iodine in soils developed over the same geologic formation decrease with increasing elevation. In certain cases, this decrease may reach up to 70%. Goiter is highly common throughout this region in Turkey. The results of this study suggest that the iodine deficiency of region’s soils may be a principal underlying cause for this area of Turkey being an endemic goiter region.     

A structural model for the seismicity of the Arudy (1980) epicentral area (Western Pyrenees, France)

The Western Pyrenees presents a diffuse and moderate ( M ≤ 5.7) instrumental seismicity. It nevertheless historically suffered from strong earthquakes (I = IX MSK). The seismic sources of these events are not yet clearly identified. We focus on the Arudy (1980) epicentral area ( M = 5.1) and propose here the reactivation of early Cretaceous normal faults of the Iberian margin as a potential source. The late Cretaceous inversion of this basin, first in a left-lateral strike-slip mode and then in a more frontal convergence, resulted in a pop-up geometry. This flower structure attests of the presence of a deep crustal discontinuity.
The present-day geodynamic arrangement suggests that this accident is reactivated in a right lateral mode. This reactivation leads to a strain partitioning between the deep discontinuity that accommodates the lateral component of the motion and shallow thrusts, rooted on this discontinuity. These thrusts accommodate the shortening component of the strain. The distribution of the instrumental seismicity fits well the structural model of the Arudy basin. Whatever the compressive regional context, the structural behaviour of the system explains too the extensive stress tensor determined for the Arudy crisis if we interpret it in terms of strain ellipsoid. Indeed numerical modelling has shown that this concomitant activity of strike-slip and thrust faulting results in an extensive component that can rise 50 per cent of the finite strain.
We identify too a 25–30 km long potential seismic source for the Arudy area. The size of the structure and its potential reactivation in a strike-slip mode suggest that a maximum earthquake magnitude of ∼6.5 could be expected. The extrapolation of this model at the scale of the Western Pyrenees allows to propose other potential sources for major regional historical earthquakes.     

Simultaneous identification of a single pollution point-source location and contamination time under known flow field conditions

A theoretical framework is presented that allows direct identification of a single point-source pollution location and time in heterogeneous multidimensional systems under known flow field conditions. Based on the concept of the transfer function theory, it is shown that an observed pollution plume contains all the necessary information to predict the concentration at the unknown pollution source when a reversed flow field transport simulation is performed. This target concentration C₀ is obtained from a quadratic integral of the observed pollution plume itself. Backwards simulation of the pollution plume leads to shrinkage of the C₀-contour due to dispersion. When the C₀-contour reduces to a singular point, i.e. becomes a concentration maximum, the position of the pollution source is identified and the backward simulation time indicates the time elapsed since the contaminant release. The theoretical basis of the method is first developed for the ideal case that the pollution plume is entirely known and is illustrated using a synthetic heterogeneous 2D example where all the hydro-dispersive parameters are known. The same example is then used to illustrate the procedure for a more realistic case, i.e. where only few observation points exist.     

SPECIFIC DEGRADATION OF WATERSHEDS

An extensive database of reservoir sedimentation surveys throughout continental United States is compiled and analyzed to determine specific degradation SD relationships as function of mean annual rainfall R, drainage area A, and watershed slope S. The database contains 1463 field measurements and specific degradation relationships are defined as function of A, R and S. Weak trends and significant variability in the data are noticeable. Specific degradation measurements are log normally distributed with respect to R, A, and S and 95% confidence intervals are determined accordingly. The accuracy of the predictions does not significantly increase as more independent variables are added to the regression analyses.     

松潘-平武地震前地震视应变场的时空演变

利用松潘-平武周边地区的地震资料研究了1970-1975年该地区地震视应变场的分布和时空变化特征。结果表明,地震视应变的时空变化与松潘-平武强震具有很好的对应关系,1970年在附近就出现异常区,并且地震视应变总体上逐年增加,地震就发生在地震视应变异常区。     

2006年甘肃文县5.0级地震灾害损失评估

2006年6月21日在甘肃省文县发生MS5.0地震,造成了建筑物破坏及人员伤亡。在震后开展的地震现场考察与震害评估工作中,将灾区分为2个评估子区,完成了29个点的震害抽样调查工作,根据地震灾害损失评估系统EDLES2.5的要求建立了有关数据库,做出了经济损失评估,并针对灾害特点给出了灾区恢复重建的建议。     

高分辨率浅层人工地震勘探探测隐伏断裂实例

利用高分辨率浅层地震勘探反射波法探测了福建某火电厂场址内的隐伏断裂。结果表明断裂显示清楚,为一走向NE40~55°,上断点埋深为11 m和31 m,断距2~4 m的正断层,为工程避让提供较可靠的依据。     

1879年甘肃武都南8级地震新史料

1985年在甘肃文县屯寨乡洋汤寨的天池庙的大樑上发现了一条新的关于1879年7月1日武都8级地震的新的历史记载。该记载表明武都8级地震在这里的地震烈度至少达到了Ⅹ度。     

江苏省锡山市西部地区地下水资源计算模型研究

从地下水运动均衡原理的角度分析江苏省锡山市西部地区第Ⅱ承压含水层天然和现状开采条件下的地下水均衡要素.揭示了该区地下水开采与地面沉降的关系,其中现状开采条件下的75%～80%的开采量来自于粘性土层的压密水量.根据地面沉降的发生机理剖析地面沉降严重发育地区忽略地面沉降影响因子建立的地下水资源计算模型中存在的问题针对存在的问题,提出了地下水可开采资源合理的计算方法,并对融有地面沉降影响因子的地下水资源计算模型的可实现性进行了分析.