Premium
Geophysical applications across the US Critical Zone Observatories (CZO) and future CZOs for the pan‐Canadian EON‐ROSE research initiative
Author(s) -
Boggs Katherine,
West Nicole,
Sullivan Pamela,
Johnson Edward
Publication year - 2019
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/1755-6724.14003
Subject(s) - rose (mathematics) , geology , earth science , geophysics , oceanography , mathematics , geometry
The Critical Zone (CZ; as first defined by the National Research Council 2001) is the Earth’s living skin, extending from the top of the tree canopy to the base of the deepest weathering and aquifers. Collaborations between geoscientists, ecologists, social scientists and others is critical for designing research approaches to address issues critical for humanity, such as: erosion and landscape evolution, water supply and quality, and nutrient cycles (Martin and Johnson 2017) . This paper will describe the applications of some geophysical approaches to CZ studies across the US CZOs and other ecosystems (Fig. 1) and then outline plans for establishing CZOs for the new pan-Canadian EONROSE research initiative. (Fig. 2). In 2008 Robinson et al outlined a vision for the use of electrical and magnetic geophysical methods to advance watershed scale hydrological research. Such methods are useful for examining the difficult to access deeper portions of the CZO; while the upper surface water, soil and vegetation are more readily accessible. Even the question of “How deep is deep” within the CZ is non-trivial, in part due to the variation between CZs and even within individual CZOs (e.g. Riebe et al 2017). Leopold et al (2013) used electrical resistivity tomography (ERT) across the Boulder Creek CZO to demonstrate that the Betasso lower montane basin and the Gordon Gulch montane basin with rolling hills are more variable than the Green Lakes valley (a glacially eroded alpine basin) due to the complex Quaternary geomorphic history in the non-glaciated montane landscapes. Parsekian et al (2014) summarized a variety of geophysical techniques (e.g. seismic nuclear magnetic resonance (NMR), electromagnetics (EM), ground-penetrating radar (GPR), and seismic methods) used to map the structures that define the architecture of Critical Zones. Such geophysical applications permit synoptic research across multiple different scales to address fundamental CZ questions such as: “How does CZ structure affect exchange of fluids between subsurface and surface reservoirs?” Where is water stored within the CZ? How thick is the regolith and how do chemical weathering, climate and biologically mediation processes impact this thickness?