Multiscale geophysical imaging of the critical zone
Multiscale geophysical imaging of the critical zone
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DOI：
10.1002/2014rg000465
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发表时间：
2015-03
影响因子：
25.2
通讯作者：
A. Parsekian;K. Singha;B. Minsley;W. Holbrook;L. Slater
中科院分区：
文献类型：
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作者：
A. Parsekian;K. Singha;B. Minsley;W. Holbrook;L. Slater
地球浅层地下的细节——临界带（CZ）的关键组成部分——在很大程度上是模糊的，因为用足够的密度进行直接观测来捕捉物理性质的自然特征空间变异性是困难的。然而，这个难以进入的CZ地区是支持生态系统、社会和环境进程的基础。地球物理方法提供了一种在厘米到公里的长度尺度上远程检查CZ形态和功能的手段。本文着重介绍了地球物理方法在CZ科学研究问题中的应用。特别是，我们考虑应用地球物理方法来绘制结构特征的几何形状，如风化层厚度、岩性边界、永久冻土范围、积雪厚度或浅根区。结合结构知识，我们讨论了如何利用地球物理观测来理解CZ过程。雪、地表水和地下水之间的通量影响风化、地下水资源以及向河流输出的化学和营养物质。利用地球物理方法研究了湿地土壤与大气之间的气体交换。间接地球物理方法是对通过钻井或野外测绘获得的直接观测的自然和必要的补充。直接测量应用于校准地球物理估计，然后可用于在更大范围内推断解释或监测随时间变化的过程。用于整合不同类型数据的地球物理仪器和计算方法的进展具有巨大的潜力，可以填补我们对CZ浅层次表层部分的理解空白，并应在未来的CZ研究中尽可能地进行整合。
Details of Earth's shallow subsurface—a key component of the critical zone (CZ)—are largely obscured because making direct observations with sufficient density to capture natural characteristic spatial variability in physical properties is difficult. Yet this inaccessible region of the CZ is fundamental to processes that support ecosystems, society, and the environment. Geophysical methods provide a means for remotely examining CZ form and function over length scales that span centimeters to kilometers. Here we present a review highlighting the application of geophysical methods to CZ science research questions. In particular, we consider the application of geophysical methods to map the geometry of structural features such as regolith thickness, lithological boundaries, permafrost extent, snow thickness, or shallow root zones. Combined with knowledge of structure, we discuss how geophysical observations are used to understand CZ processes. Fluxes between snow, surface water, and groundwater affect weathering, groundwater resources, and chemical and nutrient exports to rivers. The exchange of gas between soil and the atmosphere have been studied using geophysical methods in wetland areas. Indirect geophysical methods are a natural and necessary complement to direct observations obtained by drilling or field mapping. Direct measurements should be used to calibrate geophysical estimates, which can then be used to extrapolate interpretations over larger areas or to monitor changing processes over time. Advances in geophysical instrumentation and computational approaches for integrating different types of data have great potential to fill gaps in our understanding of the shallow subsurface portion of the CZ and should be integrated where possible in future CZ research.