Subsurface processes significantly influence surface dynamics in permafrost regions, necessitating utilizing diverse geophysical methods to reliably constrain permafrost characteristics. This research uses multiple geophysical techniques to explore the spatial variability of permafrost in undisturbed tundra and its degradation in disturbed tundra in Utqiaġvik, Alaska. Here, we integrate multiple quantitative techniques, including multichannel analysis of surface waves (MASW), electrical resistivity tomography (ERT), and ground temperature sensing, to study heterogeneity in permafrost’s geophysical characteristics. MASW results reveal active layer shear wave velocities (V_s) between 240 and 370 m/s, and permafrost V_s between 450 and 1,700 m/s, typically showing a low-high-low velocity pattern. Additionally, we find an inverse relationship between in situ V_s and ground temperature measurements. The V_s profiles along with electrical resistivity profiles reveal cryostructures such as cryopeg and ice-rich zones in the permafrost layer. The integrated results of MASW and ERT provide valuable information for characterizing permafrost heterogeneity and cryostructure. Corroboration of these geophysical observations with permafrost core samples’ stratigraphies and salinity measurements further validates these findings. This combination of geophysical and temperature sensing methods along with permafrost core sampling confirms a robust approach for assessing permafrost’s spatial variability in coastal environments. Our results also indicate that civil infrastructure systems such as gravel roads and pile foundations affect permafrost by thickening the active layer, lowering the V_s, and reducing heterogeneity. We show how the resulting V_s profiles can be used to estimate key parameters for designing buildings in permafrost regions and maintaining existing infrastructure in polar regions.

中文翻译：

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使用地震表面波、电阻率和温度传感绘制永久冻土变化和退化图：阿拉斯加北极地区的案例研究

地下过程显着影响永久冻土地区的表面动力学，因此需要利用不同的地球物理方法来可靠地约束永久冻土特征。这项研究使用多种地球物理技术来探索阿拉斯加乌特恰维克未受干扰苔原中永久冻土的空间变化及其在受干扰苔原中的退化。在这里，我们集成了多种定量技术，包括表面波多通道分析（MASW）、电阻率层析成像（ERT）和地面温度传感，来研究永久冻土地球物理特征的异质性。MASW 结果显示，活动层剪切波速度 ( V _s ) 在 240 至 370 m/s 之间，永久冻土层V _s在 450 至 1,700 m/s 之间，通常呈现低-高-低速度模式。此外，我们发现原位V _s和地面温度测量之间存在反比关系。V _s剖面以及电阻率剖面揭示了低温结构，例如永久冻土层中的冷冻层和富含冰的区域。MASW 和 ERT 的综合结果为表征永久冻土异质性和低温结构提供了有价值的信息。这些地球物理观测结果与永久冻土岩心样本的地层学和盐度测量值的证实进一步验证了这些发现。这种地球物理和温度传感方法与永久冻土岩芯采样的结合证实了评估沿海环境永久冻土空间变化的可靠方法。我们的结果还表明，碎石路和桩基等民用基础设施系统通过加厚活动层、降低V _s和减少异质性来影响永久冻土。我们展示了如何使用生成的V _{s剖面来估计永久冻土地区建筑设计和极地地区现有基础设施维护的关键参数。}