Geophysical imaging of the deep critical zone architecture reveals the
complex interplay between hydrological and weathering processes in a
volcanic tropical catchment
Abstract
The Critical Zone (CZ) evolves through weathering and erosion processes
that shape landscapes and control the availability and quality of
natural resources. Although many of these processes take place in the
deep CZ ($\sim$10-100 m), direct information about its
architecture remain scarce. Near-surface geophysics offer cost-effective
and minimally-intrusive alternatives to drilling that can provide
information about the physical properties of the CZ. We propose a novel
workflow combining geophysics, petrophysics and geostatistics to
characterize the architecture of the CZ (i.e., weathering front and
water table depths) at the catchment scale, on the volcanic tropical
island of Basse-Terre (Guadeloupe, France). Our results highlight two
spatial organizations patterns for the weathering front and the water
table, one along the stream and one transverse to it. This illustrates
the robustness and strong potential of the proposed workflow to study
hydrological and weathering processes in the CZ.