Assessment of the long term possibilities and risks related to geological storage requires insight in the deep groundwater flow systems. The objective of this paper is to show the relevance of the deep creep flow of the earth’s viscous upper mantle and crust as a complement to the groundwater flow. The paper presents an approach based on Fourier decomposition of the topography. The creep flow equations are solved analytically, which results in simple indices like penetration depth and relaxation time characterizing the gravity-driven creep flow. Thanks to the very high effective viscosity of the Earth’s subsurface a Darcy-like equation is obtained in which the ‘creep conductivity’ is Fourier mode dependent, which allows for simple comparison with the hydraulic conductivity for groundwater flow. Order of magnitude calculations indicate that for horizontal length scales of 100–1000 km the subsurface creep velocities are 0.3–30 mm/year, respectively, which shows that creep velocities in the deep subsurface are significant with respect to deep groundwater velocities.

评估与地质存储有关的长期可能性和风险需要深入了解地下水深流系统。本文的目的是显示粘性上地幔和地壳的深层蠕变流动与地下水流动的互补性的相关性。本文提出了一种基于地形的傅立叶分解的方法。蠕变方程可以通过解析求解，从而得出简单的指标，例如穿透深度和松弛时间，这些都是表征重力驱动蠕变流的特征。由于地球地下的非常高的有效粘度，得出了类似于达西的方程式，其中“蠕变电导率”与傅立叶模式有关，从而可以与地下水流动的水力电导率进行简单比较。