Video of the registration procedure in Metashape and OpenPlot. Metashape reports.
注册过程的视频在Metashape和OpenPlot。Metashape报告。
{"title":"Virtual Outcrops in a Pocket: The Smartphone as a Fully Equipped Photogrammetric Data Acquisition Tool","authors":"A. Corradetti, T. Seers, A. Billi, S. Tavani","doi":"10.1130/gsatg506a.1","DOIUrl":"https://doi.org/10.1130/gsatg506a.1","url":null,"abstract":"Video of the registration procedure in Metashape and OpenPlot. Metashape reports.<div><br></div>","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42226215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Recruiting to Geosciences through Campus Partnerships","authors":"C. Cervato","doi":"10.1130/GSATG503GW.1","DOIUrl":"https://doi.org/10.1130/GSATG503GW.1","url":null,"abstract":"","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"31 1","pages":"36-37"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41344624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Akshay Mehra, C. B. Keller, Tianran Zhang, N. Tosca, S. McLennan, E. Sperling, Una C Farrell, J. Brocks, D. Canfield, D. Cole, P. Crockford, Huan Cui, T. Dahl, K. Dewing, J. Emmings, R. Gaines, T. Gibson, G. Gilleaudeau, R. Guilbaud, Malcolm Hodgkiss, A. Jarrett, P. Kabanov, M. Kunzmann, Chao Li, D. K. Loydell, Xinze Lu, Austin J Miller, N. Mills, L. Mouro, Brennan O’Connell, S. Peters, S. Poulton, S. Ritzer, Emmy Smith, P. Wilby, C. Woltz, J. Strauss
Table of valid lithologies; map depicting sample locations; crossplot illustrating analytical uncertainty; flowchart of the proposed workflow; histograms showing the effects of progressive filtering, the distribution of spatial and age scales, and proximity and probability values; and results of parameters sensitivity tests.
{"title":"Curation and Analysis of Global Sedimentary Geochemical Data to Inform Earth History","authors":"Akshay Mehra, C. B. Keller, Tianran Zhang, N. Tosca, S. McLennan, E. Sperling, Una C Farrell, J. Brocks, D. Canfield, D. Cole, P. Crockford, Huan Cui, T. Dahl, K. Dewing, J. Emmings, R. Gaines, T. Gibson, G. Gilleaudeau, R. Guilbaud, Malcolm Hodgkiss, A. Jarrett, P. Kabanov, M. Kunzmann, Chao Li, D. K. Loydell, Xinze Lu, Austin J Miller, N. Mills, L. Mouro, Brennan O’Connell, S. Peters, S. Poulton, S. Ritzer, Emmy Smith, P. Wilby, C. Woltz, J. Strauss","doi":"10.1130/GSATG484A.1","DOIUrl":"https://doi.org/10.1130/GSATG484A.1","url":null,"abstract":"Table of valid lithologies; map depicting sample locations; crossplot illustrating analytical uncertainty; flowchart of the proposed workflow; histograms showing the effects of progressive filtering, the distribution of spatial and age scales, and proximity and probability values; and results of parameters sensitivity tests.","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44881775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bringing the Field to Students during COVID-19 and Beyond","authors":"L. Arthurs","doi":"10.1130/gsatg478gw.1","DOIUrl":"https://doi.org/10.1130/gsatg478gw.1","url":null,"abstract":"","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"31 1","pages":"28-29"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44217151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Geology in an Online World","authors":"J. Walker","doi":"10.1130/GSATPRSADRS20.1","DOIUrl":"https://doi.org/10.1130/GSATPRSADRS20.1","url":null,"abstract":"","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"31 1","pages":"4-7"},"PeriodicalIF":0.0,"publicationDate":"2021-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44118429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1130/abs/2020am-359280
Gregory Shafer, Not Provided, K. Viskupic, A. Egger
INTRODUCTION Bachelors-level geoscientists make up the majority of the geoscience workforce, and positions for entry-level geoscientists are expected to grow rapidly over the next decade, with some jobs anticipating upward of 10% growth (National Center for O*NET Development, 2021). Are geoscience departments adequately preparing undergraduate students to succeed in these positions? Answering this question requires examining the alignment of undergraduate program outcomes and workforce needs. The results allow faculty to identify strengths and weaknesses in their programs with respect to workforce preparation (e.g., Viskupic et al., 2020). How well do we know workforce needs? Vision and Change in the Geosciences (Mosher and Keane, 2021) provides a list of competencies and skills necessary for new graduates to succeed in the workforce; the list was generated by academics (n ~200) and employers (n = 46) in a series of workshops. This list, while comprehensive and insightful, represents input from a relatively small sample of geoscience employers and may overrepresent the petroleum industry (26% of industry workshop participants), which has not been a significant employer of bachelorslevel geoscientists (Gonzales and Keane, 2021). Our goal was to characterize the skills sought by the full range of bachelorslevel geoscience employers and how these skills are communicated to potential applicants—with an eye toward providing information that would allow academic leaders to examine the alignment between their programs and workforce needs.
本科水平的地球科学家占地球科学劳动力的大部分，预计在未来十年，入门级地球科学家的职位将迅速增长，其中一些职位预计将增长10%以上(National Center for O*NET Development, 2021)。地球科学系是否为本科生在这些职位上取得成功做好了充分的准备?回答这个问题需要检查本科课程成果和劳动力需求的一致性。研究结果使教师能够确定其项目在劳动力准备方面的优势和劣势(例如，Viskupic等人，2020)。我们对劳动力需求了解多少?《地球科学的愿景与变化》(Mosher和Keane, 2021)提供了新毕业生在劳动力市场取得成功所需的能力和技能清单;该榜单是由学者(n ~200)和雇主(n = 46)在一系列研讨会上得出的。这份清单虽然全面而富有洞察力，但代表了相对较小样本的地球科学雇主的输入，并且可能过度代表石油行业(26%的行业研讨会参与者)，石油行业并不是学士级地球科学家的重要雇主(Gonzales和Keane, 2021)。我们的目标是描述所有本科水平的地球科学雇主所需要的技能，以及如何将这些技能传达给潜在的申请人——着眼于提供信息，使学术领袖能够检查他们的项目与劳动力需求之间的一致性。
{"title":"ANALYSIS OF SKILLS SOUGHT BY EMPLOYERS OF BACHELORS-LEVEL GEOSCIENTISTS","authors":"Gregory Shafer, Not Provided, K. Viskupic, A. Egger","doi":"10.1130/abs/2020am-359280","DOIUrl":"https://doi.org/10.1130/abs/2020am-359280","url":null,"abstract":"INTRODUCTION Bachelors-level geoscientists make up the majority of the geoscience workforce, and positions for entry-level geoscientists are expected to grow rapidly over the next decade, with some jobs anticipating upward of 10% growth (National Center for O*NET Development, 2021). Are geoscience departments adequately preparing undergraduate students to succeed in these positions? Answering this question requires examining the alignment of undergraduate program outcomes and workforce needs. The results allow faculty to identify strengths and weaknesses in their programs with respect to workforce preparation (e.g., Viskupic et al., 2020). How well do we know workforce needs? Vision and Change in the Geosciences (Mosher and Keane, 2021) provides a list of competencies and skills necessary for new graduates to succeed in the workforce; the list was generated by academics (n ~200) and employers (n = 46) in a series of workshops. This list, while comprehensive and insightful, represents input from a relatively small sample of geoscience employers and may overrepresent the petroleum industry (26% of industry workshop participants), which has not been a significant employer of bachelorslevel geoscientists (Gonzales and Keane, 2021). Our goal was to characterize the skills sought by the full range of bachelorslevel geoscience employers and how these skills are communicated to potential applicants—with an eye toward providing information that would allow academic leaders to examine the alignment between their programs and workforce needs.","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63651875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The hypothesis that the Mesoproterozoic (1600–1000 Ma) tectonic regime was a protracted single-lid episode is explored. Singlelid tectonic regimes contrast with plate tectonics because the silicate planet or moon is encased in a single lithospheric shell, not a global plate mosaic. Single-lid tectonics dominate among the Solar System’s active silicate bodies, and these show a wide range of magmatic and tectonic styles, including heat pipe (Io), vigorous (Venus), and sluggish (Mars). Both positive and negative evidence is used to evaluate the viability of the Mesoproterozoic single-lid hypothesis. Four lines of positive evidence are: (1) elevated thermal regime; (2, 3) abundance of unusual dry magmas such as A-type granites and anorthosites; and (4) paucity of new passive continental margins. Negative evidence is the lack of rock and mineral assemblages formed by plate-tectonic processes such as ophiolites, blueschists, and ultra high-pressure terranes. Younger platetectonic–related and Mesoproterozoic mineralization styles contrast greatly. Paleomagnetic evidence is equivocal but is permissive that Mesoproterozoic apparent polar wander paths of continental blocks did not differ significantly. These tests compel the conclusion that the Mesoproterozoic single-lid hypothesis is viable.
{"title":"The Mesoproterozoic Single-Lid Tectonic Episode: Prelude to Modern Plate Tectonics","authors":"R. Stern","doi":"10.1130/gsatg480a.1","DOIUrl":"https://doi.org/10.1130/gsatg480a.1","url":null,"abstract":"The hypothesis that the Mesoproterozoic (1600–1000 Ma) tectonic regime was a protracted single-lid episode is explored. Singlelid tectonic regimes contrast with plate tectonics because the silicate planet or moon is encased in a single lithospheric shell, not a global plate mosaic. Single-lid tectonics dominate among the Solar System’s active silicate bodies, and these show a wide range of magmatic and tectonic styles, including heat pipe (Io), vigorous (Venus), and sluggish (Mars). Both positive and negative evidence is used to evaluate the viability of the Mesoproterozoic single-lid hypothesis. Four lines of positive evidence are: (1) elevated thermal regime; (2, 3) abundance of unusual dry magmas such as A-type granites and anorthosites; and (4) paucity of new passive continental margins. Negative evidence is the lack of rock and mineral assemblages formed by plate-tectonic processes such as ophiolites, blueschists, and ultra high-pressure terranes. Younger platetectonic–related and Mesoproterozoic mineralization styles contrast greatly. Paleomagnetic evidence is equivocal but is permissive that Mesoproterozoic apparent polar wander paths of continental blocks did not differ significantly. These tests compel the conclusion that the Mesoproterozoic single-lid hypothesis is viable.","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":" ","pages":"4-10"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43909440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Three-Dimensional, Virtual Tour of the Johnston Geology Museum","authors":"M. Schulmeister, Brian C. Edwards","doi":"10.1130/gsatg470gw.1","DOIUrl":"https://doi.org/10.1130/gsatg470gw.1","url":null,"abstract":"","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"30 1","pages":"24-25"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46237335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jacob Beasecker, Zach Chamberlin, Nicole Lane, Katie W. Reynolds, Jack Stack, Kailey Wahrer, Abigail Wolff, Jo Devilbliss, Corey Wahr, Dan Durbin, Hannah Garneau, D. Brandt
Environmental Sciences, Michigan State University, East Lansing, Michigan 48824, USA; Jo Devilbiss, Corey Wahr, Dept. of Integrative Biology, Michigan State University, East Lansing, Michigan 48824, USA; Dan Durbin, Hannah Garneau, Dept. of Fisheries & Wildlife, Michigan State University, East Lansing, Michigan 48824, USA; and Danita Brandt, Dept. of Earth & Environmental Sciences, Michigan State University, East Lansing, Michigan 48824, USA
{"title":"It’s Time to Defuse the Cambrian “Explosion”","authors":"Jacob Beasecker, Zach Chamberlin, Nicole Lane, Katie W. Reynolds, Jack Stack, Kailey Wahrer, Abigail Wolff, Jo Devilbliss, Corey Wahr, Dan Durbin, Hannah Garneau, D. Brandt","doi":"10.1130/gsatg460gw.1","DOIUrl":"https://doi.org/10.1130/gsatg460gw.1","url":null,"abstract":"Environmental Sciences, Michigan State University, East Lansing, Michigan 48824, USA; Jo Devilbiss, Corey Wahr, Dept. of Integrative Biology, Michigan State University, East Lansing, Michigan 48824, USA; Dan Durbin, Hannah Garneau, Dept. of Fisheries & Wildlife, Michigan State University, East Lansing, Michigan 48824, USA; and Danita Brandt, Dept. of Earth & Environmental Sciences, Michigan State University, East Lansing, Michigan 48824, USA","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"30 1","pages":"26-27"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42976868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
How soil-water flows and how fast it moves solutes are important for plant growth and soil formation. The relationship describing the partitioning of precipitation, P, into run-off, Q, and evapotranspiration, ET, is called the water balance. Q incorporates both surface runoff and subsurface flow components, the latter chiefly contributing to soil formation. At shorter time intervals, soil-water storage, S, may change, dS/dt, due to atmosphere-soil water exchange; i.e., infiltrating and evaporating water and root uptake. Over sufficiently long time periods, storage changes are typically neglected (Gentine et al., 2012). Percolation theory from statistical physics provides a powerful tool for predicting soil formation and plant growth (Hunt, 2017) by means of modeling soil pore space as networks, rather than continua. In heterogeneous soils, solute migration typically exhibits non-Gaussian behavior, with statistical models having long tails in arrival time distributions and velocities decreasing over time. Theoretical prediction of solute transport via percolation theory that generates accurate full non-Gaussian arrival time distributions has become possible only recently (Hunt and Ghanbarian, 2016; Hunt and Sahimi, 2017). A unified framework, based on solute transport theory, helps predict soil depth as a function of age and infiltration rate (Yu and Hunt, 2017), soil erosion rates (Yu et al., 2019), chemical weathering (Yu and Hunt, 2018), and plant height and productivity as a function of time and transpiration rates (Hunt, 2017). Expressing soil depth and plant growth inputs to the crop net primary productivity, NPP, permits optimization of NPP with respect to the hydrologic fluxes (Hunt et al., 2020). Some remarkable conclusions also arise from this theory, such as that globally averaged ET is almost twice Q, and that the topology of the network guiding soil-water flow provides limitations on solute transport and chemical weathering. Both plant roots and infiltrating water tend to follow paths of least resistance, but with differing connectivity properties. Except in arid climates (Yang et al., 2016), roots tend to be restricted to the thin topsoil, so lateral root distributions are often considered twodimensional (2D), and root structures employ hierarchical, directional organization, speeding transport by avoiding closed loops. In contrast, infiltrating water (i.e., the subsurface part of Q) tends to follow random paths (Hunt, 2017) and percolates through the topsoil more deeply, giving rise to three-dimensional (3D) flow-path structures. The resulting distinct topologies generate differing nonlinear scaling, which is fractal, between time and distance of solute transport. On a bi-logarithmic space-time plot (Hunt, 2017), optimal paths for the different spatiotemporal scaling laws of root radial extent (RRE) and soil depth, z, are defined by their radial divergence from the same length and time positions. RRE relates to NPP, which is a key d
土壤水如何流动以及溶质移动的速度对植物生长和土壤形成很重要。描述降水P与径流Q和蒸散发ET之间分配的关系称为水平衡。Q包含地表径流和地下流成分，后者主要有助于土壤的形成。在较短的时间间隔内，由于大气-土壤水分交换，土壤水储量S可能发生变化(dS/dt);即渗透和蒸发水分和根系吸收。在足够长的时间内，储存变化通常被忽略(genine et al.， 2012)。统计物理学的渗透理论为预测土壤形成和植物生长提供了一个强大的工具(Hunt, 2017)，方法是将土壤孔隙空间建模为网络，而不是连续的。在非均质土壤中，溶质迁移通常表现为非高斯迁移，统计模型在到达时间分布上具有长尾，速度随时间而减小。通过渗流理论对溶质输运进行理论预测，产生准确的全非高斯到达时间分布，直到最近才成为可能(Hunt和ghanbararian, 2016;Hunt and Sahimi, 2017)。基于溶质输运理论的统一框架有助于预测土壤深度作为年龄和入渗速率的函数(Yu and Hunt, 2017)、土壤侵蚀速率(Yu et al.， 2019)、化学风化(Yu and Hunt, 2018)，以及植物高度和生产力作为时间和蒸腾速率的函数(Hunt, 2017)。将土壤深度和植物生长投入表达为作物净初级生产力NPP，可以根据水文通量优化NPP (Hunt et al.， 2020)。该理论还得出了一些值得注意的结论，例如全球平均ET几乎是Q的两倍，以及引导土壤-水流动的网络拓扑结构对溶质运输和化学风化提供了限制。植物根系和渗水都倾向于遵循阻力最小的路径，但具有不同的连通性。除干旱气候外(Yang et al.， 2016)，根系往往局限于薄的表土，因此横向根系分布通常被认为是二维的(2D)，根系结构采用分层定向组织，通过避免闭环来加速运输。相比之下，入渗水(即Q的地下部分)往往遵循随机路径(Hunt, 2017)，并在表土中渗透得更深，从而产生三维(3D)流道结构。由此产生的不同拓扑结构在溶质输运的时间和距离之间产生不同的非线性标度，这是分形的。在双对数时空图(Hunt, 2017)上，根径向延伸(RRE)和土壤深度(z)的不同时空尺度规律的最优路径由它们在相同长度和时间位置的径向发散来定义。RRE通过根分形维数df与NPP相关，NPP是作物生产力的关键决定因素，由RRE NPP df 1/∝给出，2D和3D模式的df预测值分别为1.9和2.5 (Hunt和Sahimi, 2017)。基本长度/时间尺度由基本网络尺寸(由土壤粒度分布确定)及其与平均土壤-水流速的比值给出。年平均孔隙尺度流量由气候变量确定(Yu和Hunt, 2017)。每个标度关系都有一个范围，主要代表由P控制的流量范围，并将其划分为ET和Q。这一概念基础可以预测NPP对水文通量Q(调节土壤和根深)和蒸散发(由ET = P−Q给出)的依赖(调节RRE)。考虑稳态土壤深度(Yu和
{"title":"Predicting the Water Balance from Optimization of Plant Productivity","authors":"A. Hunt, B. Faybishenko, B. Ghanbarian","doi":"10.1130/gsatg471gw.1","DOIUrl":"https://doi.org/10.1130/gsatg471gw.1","url":null,"abstract":"How soil-water flows and how fast it moves solutes are important for plant growth and soil formation. The relationship describing the partitioning of precipitation, P, into run-off, Q, and evapotranspiration, ET, is called the water balance. Q incorporates both surface runoff and subsurface flow components, the latter chiefly contributing to soil formation. At shorter time intervals, soil-water storage, S, may change, dS/dt, due to atmosphere-soil water exchange; i.e., infiltrating and evaporating water and root uptake. Over sufficiently long time periods, storage changes are typically neglected (Gentine et al., 2012). Percolation theory from statistical physics provides a powerful tool for predicting soil formation and plant growth (Hunt, 2017) by means of modeling soil pore space as networks, rather than continua. In heterogeneous soils, solute migration typically exhibits non-Gaussian behavior, with statistical models having long tails in arrival time distributions and velocities decreasing over time. Theoretical prediction of solute transport via percolation theory that generates accurate full non-Gaussian arrival time distributions has become possible only recently (Hunt and Ghanbarian, 2016; Hunt and Sahimi, 2017). A unified framework, based on solute transport theory, helps predict soil depth as a function of age and infiltration rate (Yu and Hunt, 2017), soil erosion rates (Yu et al., 2019), chemical weathering (Yu and Hunt, 2018), and plant height and productivity as a function of time and transpiration rates (Hunt, 2017). Expressing soil depth and plant growth inputs to the crop net primary productivity, NPP, permits optimization of NPP with respect to the hydrologic fluxes (Hunt et al., 2020). Some remarkable conclusions also arise from this theory, such as that globally averaged ET is almost twice Q, and that the topology of the network guiding soil-water flow provides limitations on solute transport and chemical weathering. Both plant roots and infiltrating water tend to follow paths of least resistance, but with differing connectivity properties. Except in arid climates (Yang et al., 2016), roots tend to be restricted to the thin topsoil, so lateral root distributions are often considered twodimensional (2D), and root structures employ hierarchical, directional organization, speeding transport by avoiding closed loops. In contrast, infiltrating water (i.e., the subsurface part of Q) tends to follow random paths (Hunt, 2017) and percolates through the topsoil more deeply, giving rise to three-dimensional (3D) flow-path structures. The resulting distinct topologies generate differing nonlinear scaling, which is fractal, between time and distance of solute transport. On a bi-logarithmic space-time plot (Hunt, 2017), optimal paths for the different spatiotemporal scaling laws of root radial extent (RRE) and soil depth, z, are defined by their radial divergence from the same length and time positions. RRE relates to NPP, which is a key d","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"30 1","pages":"28-29"},"PeriodicalIF":0.0,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46142433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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