国际地球物理学报

这项工作评估了直接使用表面波频散曲线的从地震环境噪声增益洞察布兰斯菲尔德海峡的地壳结构的可行性和检测季节性地震速度的变化。我们互相关四年被西南极洲地震阵列记录的垂直分量的环境噪声的数据。为了估计基本模式瑞利波的格林函数，相关性被计算在4小时的段，堆叠在1年时间窗口和移动3个月的窗户。Rayleigh wave group dispersion curves are then measured on two spectral bands—primary (10–30 s) and secondary (5–10 s) microseisms—using frequency-time analysis. We analyze the temporal evolution of seismic velocity by comparing dispersion curves for the successive annual and 3-month correlation stacks. Our main assumption was that the Green’s functions from the cross-correlations, and thus the dispersion curves, remain invariant if the crustal structure remains unchanged. Maximum amplitudes of secondary microseisms were observed during local winter when the Southern Ocean experiences winter storms. The Rayleigh wave group velocity ranges between 2.1 and 3.7 km/s, considering our period range studied. Interannual velocity variations are not much evident. We observe a slight velocity decrease in summer and increase in winter, which could be attributed to the pressure melting of ice and an increase in ice mass, respectively. The velocity anomalies observed within the crust and upper mantle structure correlate with the major crustal and upper mantle features known from previous studies in the area. Our results demonstrate that the direct comparison of surface wave dispersion curves extracted from ambient noise might be a useful tool in monitoring crustal structure variations.

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未来气候变化的投影是因为它有助于在全球范围内为当地规模为适应规划的有用信息至关重要。This study investigated the future changes using four temperature related indices based on an ensemble of 14 CORDEX-Africa simulations at 0.44° × 0.44° of resolution under the RCP4.5 and RCP8.5 scenarios. These indices indicate moderate extremes over Côte d’Ivoire. The results show an increase in the warm extreme indices such as the warm spell days index (HWFI), very warm days frequency index (TX90P), and the warm nights frequency index (TN90P) over the entire country under both emission scenarios. The increase in these indices was higher under RCP8.5 and reached 85, 72, and 90% for HWFI, TX90P, and TN90P respectively. In addition, the magnitude of the changes is relevant along the coastal areas in the 2031–2060 and 2071–2100 periods. Moreover, the intra period extreme temperature range (ETR) shows future decrease following a south-north gradient with values in the range [−0.5; 1.5°C] over the country during January–March (JFM) and October–December (OND) seasons whereas an increase (~0.5°C) is projected for April–June (AMJ) and July–September (JAS) seasons, particularly in the central and northern parts. The minimum temperature increases faster than the maximum, except in AMJ and JAS in the central and northern regions. On the other hand, the changes in the indices based on the mean values of the reference period (1976–2005) are in concordance to the expected warming at the end of the twenty-first century with important trends. The projected changes are, however, subject to uncertainties, which are higher under RCP8.5 than under RCP4.5 scenarios. Overall, these changes are meaningful as all the 14 CORDEX-Africa simulations agree to an increase of warm extreme temperature.

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电阻率和激发极化法的组合被应用于爱丽丝，东开普省，南非固体废物填埋场划定岩性层，并找到可能的渗滤液羽。电阻率和IP数据进行了六个人去收集个人资料;两个和偶极配置VES在其余四宗使用。The result shows a 4-layered earth system with a shallow depth to the top of the bedrock (<10 m). Contaminants ranging from unsaturated waste with high ion content to dense aqueous phase liquid contaminants, characterized by low resistivity (34–80 Ohm-m) and low chargeability values (0.05–5.75 ms). The contamination was interpreted based on resistivity/IP anomalies considering the background geology. The shallow bedrock indicated a low risk to groundwater contamination because of its competent nature from its geology, and characteristic high resistivity values (≥1000 Ohm-m). However, the steep nature of the landfill terrain due to its location at the foot of a vertical slope favours the rapid migration of the contaminants into the immediate vicinity of the landfill. The construction of containment structures such as waste cells will help in enhancing effective waste management practices in the landfill.

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在本文中，我们报告在科尔戈站（纬度9.3°N。;长°E 354.6;浸°S 0.6）测量的foF2数据相比于用IRI-2012子程序URSI和CCIR预测为不同的太阳能周期阶段（最小，升，最大下降）和不同的地磁活动课（安静，波动，反复发作，休克）。根据我们的调查，与IRI预测与白天测得的数据相一致，并显示在夜间，尤其是日出前他们之间显著的差异。除了在太阳能最小，相对于安静和波动状况的预测和测量的数据之间的间隙期间是经常性和冲击条件更明显。我们的研究结果还表明，只有URSI模型在反复天，并在对波动的活性上升阶段表现的EXB漂移现象在太阳活动高峰阶段的签名。

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我们演示使用自然电位法研究火山的环境，在这种环境下特别流体流量的价值。我们展示的事实，自然电位测量火山系统的大面积下挑战性的地形条件，在其他地球物理技术可以挑战或昂贵的部署映射一个非常有效的方式。使用各种火山类型，包括凝灰岩锥，盾状火山，成层火山，和单基因领域的案例研究，我们强调一个事实，即自电位信号使我们能够研究在多时空尺度火山设置流体流动。我们分类的实例为以下三个多尺度流体流动过程：（1）深热液系统，（2）浅热液系统，和（3）的地下水。这些例子突出不同的水文，水热法，以及可以从自然电位的信号，如洞察浅层和深层热液系统可以进行结构的推断，冷却熔岩的行为流，不同的水文地质结构域，上升流，渗透，和地下水侧向和热液流体流动路径和速度，地下水位的标高，火山口限制，区域断裂，断裂带，初期塌陷限制，结构域，和埋火山口。在本文介绍的案例研究清楚地表明，所测得的SP信号是微尺度的过程（例如，电动，热电）和宏观结构和环境特征之间的coplay的结果。试图唯一地解释自然电位信号，当我们讨论潜在的挑战及其原因。通过与不同的地球物理和地球化学数据类型，如从例如电阻率成像或大地电磁，土壤CO获得地下电阻率分布的集成₂通量，和土壤温度，则证明来自SP测量获得的水文地质解释可以更好地约束和/或验证。

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滑坡变形涉及大约所有的地质材料（天然岩石，土壤，人工填土，或这些材料的组合），并可以发生在种类繁多的体积和形状的开发。材料的不均匀性和其性能的表征，变形过程的研究，以及边界和潜在滑面的划分并非简单的目标。由于上世纪70年代，国际社会（主要是地球物理学家和地质学家较低，地质工程师）已开始采用，与其他技术，地球物理方法来描述和监测山体滑坡在一起。无论是相关联的优点和局限性已经强调，多年来，和一些缺点仍然是开放的。这种审查的重点是在过去12年（2007至18年）的作品，主要目的是分析旨在克服在2007年的地球物理学和山体滑坡审查强调地球物理技术限制地球物理界的努力。为了达到这个目的，违背先前条评论分析的优点和使用每种技术的局限性“的技术途径”的分析进行了使用更近的山体滑坡分类的基础上，“材料滑坡办法”。

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