3D Seismic Anatomy of a Watershed Reveals Climate‐Topography Coupling That Drives Water Flowpaths and Bedrock Weathering

Abstract

Processes that transform bedrock into the porous regolith include fracturing, dissolution, precipitation, mechanical disaggregation, plant-and animal-related processes, and biogeochemical breakdown (e.g., Riebe et al., 2017).Regolith is important because it provides nutrients that support terrestrial life and porosity that stores groundwater (e.g., Graham et al., 2010;Riebe et al., 2017). Regolith is thinned by erosion, which physically removes material from the land surface, sometimes flattening and sometimes creating relief, shaping Earth's surface morphology and its Critical Zone (CZ) (Brantley et al., 2007). Recently, a few models have been presented that explain how the thickness of regolith responds to long-term changes in tectonics and climate (e.g., Dunne, 1990;Riebe et al., 2017;West, 2012).

Using Homogenized Models to Explore the Effect of Fracture Densities on Weathering

“…For some systems it might be more likely that new joints could be continuously forming at the bottom of the column, perhaps in response to exhumation. This is an important question because many workers argue that weathering is affected as fractures open during rock exhumation (St. Clair et al, 2015;Wang et al, 2021).…”

Mapping Variations in Bedrock Weathering With Slope Aspect Under a Sedimentary Ridge‐Valley System Using Near‐Surface Geophysics and Drilling

“…Documenting the structure of the critical zone, including the thickness and subsurface topography of different materials, is therefore crucial to quantifying water storage (Callahan et al., 2020; Flinchum, Holbrook, Rempe, et al., 2018; Rempe & Dietrich, 2014) and predicting ecosystem and landscape response to climate change (Callahan et al., 2022; Godderis & Brantley, 2013; Sullivan et al., 2022). Water storage dynamics are not homogenous at the hillslope scale but are influenced by microtopography (Wang et al., 2021), elevation (Klos et al., 2018; Nielsen et al., 2021), and slope aspect (Anderson et al., 2014). Critical zone structure can additionally be modulated by lithology (Hahm et al., 2014; Leone et al., 2020) and climate (Anderson et al., 2019; Inbar et al., 2018).…”

“…Seismic refraction can effectively capture the heterogeneity in the subsurface weathered bedrock structure, which can vary drastically from ridge to channel (Leone et al, 2020;Pasquet et al, 2022;Wang et al, 2021). By combining borehole and geophysical methods, recent studies have calibrated geophysical data to direct observations to infer weathering thickness across a landscape (Flinchum, Holbrook, Rempe, et al, 2018;Gu et al, 2020;Hayes et al, 2019;Holbrook et al, 2014Holbrook et al, , 2019Olona et al, 2010).…”

Catchment‐Scale Architecture of the Deep Critical Zone Revealed by Seismic Imaging

“…Minimally invasive surface‐based geophysical methods can be used to fill spatial gaps between wells by producing higher lateral resolution and lower cost data (Hubbard & Linde, 2011; Parsekian et al., 2015). Over the past 10 years, an increasing number of studies have used near surface geophysics to image the architecture of the CZ (Befus et al., 2011; Braun et al., 2009; Comas et al., 2019; Eppinger et al., 2021; Leopold et al., 2013; Novitsky et al., 2018; Olona et al., 2010; Orlando et al., 2016; Parsekian et al., 2021; Pasquet, Bodet, Longuevergne, et al., 2015; St. Clair et al., 2015; Wang et al., 2021, 2022; Yaede et al., 2015). These methods measure different geophysical parameters (e.g., electrical resistivity, seismic velocity), which are sensitive to a wide range of physical properties of the subsurface materials (e.g., porosity, density, water or clay content).…”