Geomagnetic disturbances cause perturbations in the Earth’s magnetic field which, by the principle of electromagnetic induction, in turn cause electric currents to flow in the Earth. These geomagnetically induced currents (GICs) also enter man-made technological conductors that are grounded; notably, telegraph systems, submarine cables and pipelines, and, perhaps most significantly, electric power grids, where transformer groundings at power grid substations serve as entry points for GICs. The strength of the GICs that flow through a transformer depends on multiple factors, including the spatiotemporal signature of the geomagnetic disturbance, the geometry and specifications of the power grid, and the electrical conductivity structure of the Earth’s subsurface. Strong GICs are hazardous to power grids and other infrastructure; for example, they can severely damage transformers and thereby cause extensive blackouts. Extreme space weather is therefore hazardous to man-made technologies. The phenomena of extreme geomagnetic disturbances, including storms and substorms, and their effects on human activity are commonly referred to as geomagnetic hazards. Here, we provide a review of relevant GIC studies from around the world and describe their common and unique features, while focusing especially on the effects that the Earth’s electrical conductivity has on the GICs flowing in the electric power grids.

中文翻译：

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全球/区域地球电导率模型在减轻自然地磁灾害中的作用

地磁扰动会引起地球磁场的扰动，根据电磁感应原理，这反过来又会导致电流在地球中流动。这些地磁感应电流 (GIC) 也会进入接地的人造技术导体；尤其是电报系统、海底电缆和管道，也许最重要的是电网，其中电网变电站的变压器接地作为 GIC 的入口点。流经变压器的 GIC 的强度取决于多种因素，包括地磁扰动的时空特征、电网的几何形状和规格，以及地球地下的导电结构。强 GIC 对电网和其他基础设施有害；例如，它们会严重损坏变压器，从而导致大面积停电。因此，极端太空天气对人造技术是有害的。包括风暴和亚暴在内的极端地磁扰动现象及其对人类活动的影响通常被称为地磁灾害。在这里，我们回顾了来自世界各地的相关 GIC 研究并描述了它们的共同和独特特征，同时特别关注地球的电导率对在电网中流动的 GIC 的影响。它们对人类活动的影响通常被称为地磁危害。在这里，我们回顾了来自世界各地的相关 GIC 研究并描述了它们的共同和独特特征，同时特别关注地球的电导率对在电网中流动的 GIC 的影响。它们对人类活动的影响通常被称为地磁危害。在这里，我们回顾了来自世界各地的相关 GIC 研究并描述了它们的共同和独特特征，同时特别关注地球的电导率对在电网中流动的 GIC 的影响。