Controls on deep critical zone architecture: a historical review and four testable hypotheses

Earth Surface Processes and Landforms, Journal Year: 2016, Volume and Issue: 42(1), P. 128 - 156

Published: Sept. 17, 2016

Abstract The base of Earth's critical zone (CZ) is commonly shielded from study by many meters overlying rock and regolith. Though deep CZ processes may seem far removed the surface, they are vital in shaping it, preparing for infusion into biosphere breaking Earth materials down transport across landscapes. This special issue highlights outstanding challenges recent advances research a series articles that we introduce here context relevant literature dating back to 1500s. Building on several contributions issue, highlight four exciting new hypotheses about factors drive weathering thus influence evolution life‐sustaining architecture. These have emerged recently developed process‐based models subsurface phenomena including: fracturing related stress fields; drainage bedrock under hydraulic head gradients; damage frost cracking due temperature mineral reactions with reactive fluids chemical potential gradients. predict distinct patterns thickness can be compared observations drilling, sampling geophysical imaging. We synthesize an overarching conceptual model occurs as exhumed surface gradients stress, head, temperature, potential. conclude call coordinated measurement campaign designed comprehensively test range climatic, tectonic geologic conditions. Copyright © 2016 John Wiley & Sons, Ltd.

Language: Английский

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A review of CO₂ and associated carbon dynamics in headwater streams: A global perspective

Reviews of Geophysics, Journal Year: 2017, Volume and Issue: 55(2), P. 560 - 585

Published: May 31, 2017

Abstract Terrestrial carbon export via inland aquatic systems is a key process in the global cycle. It includes loss of to atmosphere outgassing from rivers, lakes, or reservoirs and fixation water column as well sediments. This review focuses on headwater streams that are important because their stream biogeochemistry directly reflects input soils groundwaters. Major drivers dioxide partial pressures ( p CO 2 ) mechanisms terrestrial dissolved inorganic, organic particulate (DIC, DOC, POC) influxes summarized this work. Our analysis indicates river average 3100 ppmV more often exceeded by contributions small when compared rivers with larger catchments (> 500 km ). Because large proportion networks 96% total number streams), headwaters contribute large—but still poorly quantified—amounts atmosphere. Conservative estimates imply globally 36% (i.e., 0.93 Pg C yr −1 originate headwaters. We also discuss challenges determination sources, concentrations, fluxes. To overcome uncertainties sources its scale, new investigations needed should include groundwater data. Such studies would benefit applications integral isotope approaches multiscale geophysical imaging techniques.

Language: Английский

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Expanding the role of reactive transport models in critical zone processes

Earth-Science Reviews, Journal Year: 2016, Volume and Issue: 165, P. 280 - 301

Published: Oct. 5, 2016

Language: Английский

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Hydrological partitioning in the critical zone: Recent advances and opportunities for developing transferable understanding of water cycle dynamics

Water Resources Research, Journal Year: 2015, Volume and Issue: 51(9), P. 6973 - 6987

Published: Aug. 7, 2015

Hydrology is an integrative discipline linking the broad array of water-related research with physical, ecological, and social sciences. The increasing breadth hydrological research, often where subdisciplines hydrology partner related sciences, reflects central importance water to environmental science, while highlighting fractured nature itself. This lack coordination among hydrologic has hindered development theory integrated models capable predicting partitioning across time space. recent concept critical zone (CZ), open system extending from top canopy base groundwater, brings together multiple physical ecological Observations obtained by CZ researchers provide a diverse range complementary process structural data evaluate both conceptual numerical models. Consequently, cross-site focus on “critical hydrology” potential advance facilitate transition observatories into network immediate societal relevance. Here we review work in catchment hydrochemistry, hydrogeology, ecohydrology that highlights common knowledge gap how precipitation partitioned zone: “how amount, routing, residence subsurface biogeophysical structure CZ?” Addressing this question will require interfacing catalyze rapid progress understanding current climate land cover changes affect partitioning.

Language: Английский

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A gridded global data set of soil, intact regolith, and sedimentary deposit thicknesses for regional and global land surface modeling

Journal of Advances in Modeling Earth Systems, Journal Year: 2015, Volume and Issue: 8(1), P. 41 - 65

Published: Dec. 14, 2015

Abstract Earth's terrestrial near‐subsurface environment can be divided into relatively porous layers of soil, intact regolith, and sedimentary deposits above unweathered bedrock. Variations in the thicknesses these control hydrologic biogeochemical responses landscapes. Currently, Earth System Models approximate thickness permeable bedrock as uniform globally, despite fact that their vary systematically with topography, climate, geology. To meet need for more realistic input data models, we developed a high‐resolution gridded global set average within each 30 arcsec (∼1 km) pixel using best available geology input. Our partitions land surface upland hillslope, valley bottom, lowland landscape components uses models optimized landform type to estimate subsurface layer. On hillslopes, is calibrated validated independent sets measured soil from U.S. Europe on lowlands depth observations groundwater wells We anticipate will prove useful an regional hydrological ecosystems models.

Language: Английский

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Groundwater in the Earth's critical zone: Relevance to large‐scale patterns and processes

Water Resources Research, Journal Year: 2015, Volume and Issue: 51(5), P. 3052 - 3069

Published: April 25, 2015

Abstract Although we have an intuitive understanding of the behavior and functions groundwater in Earth's critical zone at scales a column (atmosphere‐plant‐soil‐bedrock), along toposequence (ridge to valley), across small catchment (up third‐order streams), this paper attempts assess relevance large‐scale patterns processes such as represented global climate Earth system models. Through observation syntheses conceptual models, evidence are presented that influence is globally prevalent, it forms environmental gradient not fully captured by climate, can profoundly shape evolution continental scales. Four examples used illustrate these ideas: (1) water source for plants rainless periods, (2) table depth driver plant rooting depth, (3) accessibility ecological niche separator, (4) lower boundary land drainage wetlands. The implications past future change briefly discussed, well discipline, scale, data gaps must be bridged order us translate what learn field column, hillslope scales, predict regional, continental,

Language: Английский

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Geophysical Monitoring of Moisture‐Induced Landslides: A Review

Reviews of Geophysics, Journal Year: 2018, Volume and Issue: 57(1), P. 106 - 145

Published: Nov. 16, 2018

Abstract Geophysical monitoring of landslides can provide insights into spatial and temporal variations subsurface properties associated with slope failure. Recent improvements in equipment, data analysis, field operations have led to a significant increase the use such techniques monitoring. methods complement intrusive approaches, which sample only very small proportion subsurface, walk‐over or remotely sensed data, principally information at ground surface. In particular, recent studies show that advances geophysical instrumentation, processing, modeling, interpretation context landslide are significantly improving characterization hillslope hydrology soil rock strength their dynamics over time. This review appraises state art monitoring, as applied moisture‐induced landslides. Here we focus on technical practical uses time‐lapse geophysics landslide. The case identified this several currently used processes. These contributions predicting evolution processes underrealized. Hence, further integration multiple‐parametric geotechnically coupled systems has considerable potential. complementary nature certain map distribution moisture elastic moduli will greatly predictive capacity early warning settings.

Language: Английский

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CO2 evasion along streams driven by groundwater inputs and geomorphic controls

Nature Geoscience, Journal Year: 2018, Volume and Issue: 11(11), P. 813 - 818

Published: Oct. 22, 2018

Language: Английский

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Continental-scale analysis of shallow and deep groundwater contributions to streams

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: March 4, 2021

Abstract Groundwater discharge generates streamflow and influences stream thermal regimes. However, the water quality buffering capacity of groundwater depends on aquifer source-depth. Here, we pair multi-year air temperature signals to categorize 1729 sites across continental United States as having major dam influence, shallow or deep signatures, lack pronounced (atmospheric) signatures. Approximately 40% non-dam have substantial contributions indicated by characteristic paired signal metrics. Streams with signatures account for half all signature show reduced baseflow a higher proportion warming trends compared These findings align theory that is more vulnerable increase depletion. atmospheric tend drain watersheds low slope greater human disturbance, indicating stream-groundwater connectivity in populated valley settings.

Language: Английский

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Toward catchment hydro‐biogeochemical theories

Wiley Interdisciplinary Reviews Water, Journal Year: 2020, Volume and Issue: 8(1)

Published: Dec. 3, 2020

Abstract Headwater catchments are the fundamental units that connect land to ocean. Hydrological flow and biogeochemical processes intricately coupled, yet their respective sciences have progressed without much integration. Reaction kinetic theories prescribe rate dependence on environmental variables (e.g., temperature water content) advanced substantially, mostly in well‐mixed reactors, columns, warming experiments considering characteristics of hydrological at catchment scale. These shown significant divergence from observations natural systems. On other hand, theories, including transit time theory, substantially not been incorporated into understanding reactions Here we advocate for development integrated hydro‐biogeochemical across gradients climate, vegetation, geology conditions. The lack such presents barriers mechanisms forecasting future Critical Zone under human‐ climate‐induced perturbations. Although integration has started co‐located measurements well way, tremendous challenges remain. In particular, even this era “big data,” still limited by data will need (1) intensify beyond river channels characterize vertical connectivity broadly shallow deep subsurface; (2) expand older dating scales reflected stable isotopes; (3) combine use reactive solutes, nonreactive tracers, (4) augment environments undergoing rapid changes. To develop it is essential engage models all stages model‐informed collection strategies maximize usage; adopt a “simple but simplistic,” or fit‐for‐purpose approach include process‐based models; blend data‐driven framework “theory‐guided science.” Within hypothesis testing, model‐data fusion can advance mechanistically link catchments' internal structures external drivers functioning. It only field hydro‐biogeochemistry, also enable hind‐ fore‐casting serve society large. Broadly, education cultivate thinkers intersections traditional disciplines with hollistic approaches interacting complex earth This article categorized under: Engineering Water > Methods

Language: Английский

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