Geophysical Signatures of Subsurface Microbial Processes

Abstract

Microbes are found in almost every conceivable part of the Earth, from hydrothermal vents in the deep ocean basins [Huber et al., 2007] to the cold subglacial lakes of Antarctic ice sheets [Mikucki et al., 2009]. The role of microorganisms in transforming Earth systems (e.g., accelerating mineral weathering) by mediating different biogeochemical cycles over the past 4 billion years has been well documented in many studies [e.g., Banfield et al., 1999]. However, microbial processes are challenging to investigate in situ. Direct (e.g., microbial composition and population density) and indirect (e.g., alteration of mineral phases by microbial activity) evidence for microbial activity requires sampling from boreholes, which is costly and invasive and provides poor spatial coverage.

High-resolution induced polarization imaging of biogeochemical carbon turnover hotspots in a peatland

“…The principle of reciprocity asserts that normal and reciprocal readings should be the same (e.g., Slater et al, 2000). Hence, we use here the analysis of the discrepancy between normal and reciprocal readings to detect outliers and to quantify data error (LaBrecque et al, 1996;Flores Orozco et al, 2012a;Slater and Binley, 2006;Slater et al, 2000). In this study, we quantified the error parameter for each line collected as normal and reciprocal pairs (using the approach outlined by Flores Orozco et al, 2012a) and computed the average value of the error parameters for the different lines to define the error model used for the inversion of all imaging data sets.…”

“…For the phase, the error model is also expressed as a function of the resistance s(φ a ) = cR d , where d<0 in our study due to the relatively low range in the measured resistances (see Flores Orozco et al, 2012a, for further details). If d → 0, the model reduces to the constant-phase-error model (Flores Orozco et al, 2012a) with s(φ) = c described by Kemna (2000) and Slater and Binley (2006).…”

The promises of studying cultural archeoastronomy across the Pacific Basin as a new scholarly science education research agenda

“…Taking his lead, and combining the rich traditions, methods, and knowledge of anthropology, linguistics, history, archeology, and horizon- Scholars have aggressively argued elsewhere that cultural archeoastronomy studies leading up to today have been dominated by Western European traditions and Western European voices (López, 2019). As a community, we are convinced that our scholarly work would be better informed and more solidly robust if a wider diversity of scholarly voices influenced the work (Slater et al, 2011). Not only are there invested elders that come from non-academic traditions who could make cultural archeoastronomy better, there are many astronomers who know little of the techniques of historical document analysis, many linguists who know little of the changing patterns in the sky, and many art historians who know little of why sky phenomena might influence architecture.…”

Resources in the Near-Surface Earth: An Introduction and Overview

“…More recently, the term 'biogeophysics' has been used to describe an even newer Earth science subdiscipline concerned with the geophysical signatures of microbial interactions with geologic media (Slater and Atekwana, 2013). The majority of biogeophysics research to date has focused on the near-surface Earth given the need to monitor biogeochemical transformations associated with the natural attenuation and/or enhanced remediation of groundwater contamination.…”