Academic Appointments


Administrative Appointments


  • Assistant Professor, Stanford University (2007 - Present)
  • Visiting Professor, Hydrogeology, Colorado College (2007 - 2007)
  • Mendenhall Postdoctoral Fellow, U.S. Geological Survey (2005 - 2007)

Honors & Awards


  • NSF CAREER Award, National Science Foundation (2013)
  • Allen V. Cox Award for Mentoring of Undergraduate Research, Stanford University (2012)
  • Distinguished Lecturer, Global Climate and Energy Project (GCEP ) (2012)
  • Terman Fellowship, Stanford University (2008-2011)
  • SEGRF Scholar, Lawrence Livermore National Laboratory (2002 - 2005)
  • ARCS Foundation Scholar, U.C. Berkeley (2000 - 2001)

Boards, Advisory Committees, Professional Organizations


  • Steering Committee, National Science Foundation Critical Zone Observatory (CZO) Program, National Science Foundation (2015 - Present)
  • Co-organizer of NSF workshop on “Research Infrastructure in Support of NSF-SEP Grand Challenges”, National Science Foundation (2014 - Present)
  • Director of Undergraduate Studies, GES Department, Stanford University (2014 - Present)
  • Member, Stanford Center for Carbon Storage, Stanford University (2012 - Present)
  • Organizer, School of Earth Sciences Distinguished Lecture Program Committee, Stanford University (2012 - Present)
  • Advisor for the GES Undergraduate Major and Minor, GES Department, Stanford University (2010 - Present)
  • Member, Geochronology Steering Committee, School of Earth Sciences, Stanford University (2010 - Present)
  • Member, SHRIMP-RG Advisory Committee, School of Earth Sciences, Stanford University (2010 - Present)
  • Associate Editor, American Journal of Science (appointed through 2015), American Journal of Science (2009 - Present)
  • Instructor/Presenter, Bay Area Geoscapes Teacher Education Program, Stanford University (2009 - Present)
  • Member, Jasper Ridge Biological Preserve Advisory Board, Stanford University (2009 - Present)
  • Director, Stanford ICPMS/TIMS Facility, School of Earth Sciences, Stanford University (2008 - Present)
  • Member, Undergraduate Curriculum Committee, GES Department, Stanford University (2008 - Present)
  • Member, U.S. Geological Survey Hiring Panel, U.S. Geological Survey (2015 - 2015)
  • Member, search committee for land-water systems position, EESS, Stanford University (2015 - 2015)
  • Co-organizer of NSF workshop on "The Role of Reactive Transport Models in Biogeochemical Sciences", National Science Foundation (2014 - 2015)
  • Organizer and instructor, Stanford Reactive Transport (StaRT) Summer School, Stanford University (2014 - 2015)
  • Member, School of Earth Sciences teaching task force, Stanford University (2013 - 2014)
  • Co-instructor, 2-day short course, "Reactive transport modeling using The Geochemist’s Workbench® ", Goldschmidt Conference (2013 - 2013)
  • Keynote Speaker, Goldschmidt Conference, Florence, Italy, Goldschmidt Conference (2013 - 2013)
  • Panelist, Hydrologic Sciences, National Sciences Foundation (2013 - 2013)
  • Theme Organizer (Climate, Weathering and Tectonics) and Session Chair, Goldschmidt Conference, Florence, Italy, Goldschmidt Conference (2013 - 2013)
  • Member, Selection Committee for the Stanford Interdisciplinary Graduate Fellowships (SIGF), Stanford University (2012 - 2014)
  • Invited Abstracts: American Geophysical Union Fall Meeting, San Francisco, CA, American Geophysical Union (2012 - 2012)
  • Invited Abstracts: Goldschmidt Conference, Montreal, Canada;, Goldschmidt Conference (2012 - 2012)
  • Invited Lecturer, LCLS/SSRL Users' Meeting and Workshop, “Opportunities with Synchrotron Radiation at the Mesoscale", Stanford University (2012 - 2012)
  • Invited Lecturer, Symposium, “Opportunities with Synchrotron Radiation at the Mesoscale", Exxon-Mobil, DuPont, Schlumberger and General Electric, University of Oregon (2012 - 2012)
  • Member, Advisory Committee for Molecular Environmental and Interface Science (MEIS), SSRL/SLAC, Molecular Environmental and Interface Science (MEIS), SSRL/SLAC (2012 - 2012)
  • Invited Abstract, American Geophysical Union Fall Meeting, San Francisco, CA, American Geophysical Union (2011 - 2011)
  • Invited Abstracts: Goldschmidt Conference, Prague, Czech Republic, Goldschmidt Conference (2011 - 2011)
  • Invited Lecturer: Yale University, UC Berkeley, GCEP Research Symposium, Yale, UC Berkeley, and Global Climate and Energy Project (2011 - 2011)
  • Invited Participant: "Design of Global Environmental Gradient Experiments using International CZO (Critical Zone Observatory) Networks", University of Delaware (2011 - 2011)
  • Invited Participant: ICDP/Oman Drilling Workshop, International Continental Scientific Drilling Program (2011 - 2011)
  • Co-instructor, 2-day short course, "Reactive transport modeling using The Geochemist’s Workbench® " (with Craig Bethke), Stanford University (2010 - 2010)
  • Invited Abstracts: American Geophysical Union Fall Meeting, San Francisco, CA, American Geophysical Union (2010 - 2010)
  • Invited Abstracts: Geological Society of America Conference, Denver, CO, Geological Society of America (2010 - 2010)
  • Invited Lecturer, California Institute of Technology, UCLA, Boston University, Rice University (2010 - 2010)
  • Keynote Speaker, Goldschmidt Conference, Knoxville, TN, Goldschmidt Conference (2010 - 2010)
  • Member, STREAM (Stanford Training, Research & Mentoring) Advisory Board, School of Earth Sciences, Stanford University (2009 - 2012)
  • Member, Undergraduate Field Program Committee, GES Department, Stanford University (2009 - 2012)
  • Organizer, GES Department Seminar Program, Stanford University (2009 - 2012)
  • Co-editor, (Special Volume): “Combined ecological and geologic perspectives in ecosystem studies”, Chemical Geology (2009 - 2009)
  • Invited Abstracts: American Geophysical Union (AGU) Fall Meeting, San Francisco, CA, American Geophysical Union (2009 - 2009)
  • Invited Lecturer, Duke University, UC Davis, University of Delaware (2009 - 2009)
  • Invited Participant: “Critical Zone II: Biological Aspects of Weathering”, Washington, DC, Washington, DC (2009 - 2009)
  • Member, DUSEL Experimental Design Team (THMCB), DUSEL (2009 - 2009)
  • Symposium Chair, Goldschmidt Conference: “Bridging the gap between theory and the field in critical zone processes”, Goldschmidt Conference (2009 - 2009)
  • ticipant, Experimental Coordination Workshop, Lead, SD, DUSEL (Deep Underground Science and Engineering Laboratory) (2009 - 2009)
  • Invited Abstracts: Geological Society of America Fall Meeting, Houston, TX, Geological Society of America (2008 - 2008)
  • Invited Lecturer, Lawrence Berkeley National Laboratory (2008 - 2008)
  • Member, Search Committee, Geochronology, Petrology, Geodynamics position, GES Department, Stanford University (2008 - 2008)
  • Symposium Chair, Goldschmidt Conference: “Chemical and isotopic tracers of sediment-pore fluid interactions”, Cologne, Germany, Goldschmidt Conference (2008 - 2008)
  • Symposium Chair, Goldschmidt Conference: “Isotopic and geochemical insights into the rates and mechanisms of erosion and weathering”, Cologne, Germany, Goldschmidt Conference (2008 - 2008)
  • Invited Lecturer, Yale University, ETH Zurich, Geological Society of Washington D.C., U.S. Geological Survey, Reston VA (2007 - 2007)
  • Symposium Chair, AGU Fall Meeting: “Controls on geochemical and biogeochemical processes in the critical zone”, San Francisco, CA, American Geophysical Union (2007 - 2007)

Professional Education


  • Ph.D., U.C. Berkeley, Earth and Planetary Sciences (2005)
  • M.S., U.C. Berkeley, Civil and Environmental Engineering (Fluid Mechanics/Hydrology) (2001)
  • B.S., Environmental Earth Sciences, Dartmouth College (1999)

Current Research and Scholarly Interests


Research
Chemical reactions between fluids and minerals create the environments that are uniquely characteristic of Earth’s surface. For example, chemical weathering reactions support the growth of soils and organisms and regulate the flow of elements to the oceans. The rates of these reactions also control the release and storage of natural and human-derived contaminants. Over geologic timescales, mineral-fluid reactions have helped to maintain a mostly habitable planet. Over human timescales, these reactions will regulate our ability to use Earth’s resources, such as soils, waters, and minerals.

My research focuses on the rates of reactions in different environments using a combination of geochemical tools, including isotope geochemistry, geochemical and hydrologic modeling, and geochronology in order to address the following themes: (1) defining the controls on mineral-fluid reactions rates in the environment (2) finding new approaches to use mineral-fluid reactions to safely store carbon dioxide in the subsurface; and (3) development of isotopic approaches to study mineral-fluid reactions in the environments of Earth’s past. To support these research themes, I have constructed a new mass spectrometer and clean lab facility capable of high precision geochemical and isotopic measurements, and teach a number of classes and short courses on reactive transport.

Teaching
My teaching focuses on introducing students to the questions and major challenges in low temperature and environmental geochemistry, and the application of isotope geochemistry to environmental and geologic problems. In order to introduce incoming students to Earth surface processes, materials and geochemistry, I am also teaching a freshman seminar on forensic geoscience. At the graduate level, I offer classes on isotope geochemistry and modeling of environmental transformations and mass transfer processes (i.e., subsurface reactive transport).

2014-15 Courses


Postdoctoral Advisees


Journal Articles


  • Sedimentary reservoir oxidation during geologic CO2 sequestration GEOCHIMICA ET COSMOCHIMICA ACTA Lammers, L. N., Brown, Jr., G. E., Bird, D. K., Thomas, R. B., Johnson, N. C., Rosenbauer, R. J., Maher, K. 2015; 155: 30-46
  • Steering of westerly storms over western North America at the Last Glacial Maximum NATURE GEOSCIENCE Oster, J. L., Ibarra, D. E., Winnick, M. J., Maher, K. 2015; 8: 201–205

    View details for DOI 10.1038/ngeo2365

  • Rise and fall of late Pleistocene pluvial lakes in response to reduced evaporation and precipitation: Evidence from Lake Surprise, California GEOLOGICAL SOCIETY OF AMERICA BULLETIN Ibarra, D. E., Egger, A. E., Weaver, K. L., Harris, C. R., Maher, K. 2014; 126 (11-12): 1387-1415

    View details for DOI 10.1130/B31014.1

    View details for Web of Science ID 000343759600001

  • The impact of neogene grassland expansion and aridification on the isotopic composition of continental precipitation GLOBAL BIOGEOCHEMICAL CYCLES Chamberlain, C. P., Winnick, M. J., Mix, H. T., Chamberlain, S. D., Maher, K. 2014; 28 (9): 992-1004
  • Modeling the influence of organic acids on soil weathering GEOCHIMICA ET COSMOCHIMICA ACTA Lawrence, C., Harden, J., Maher, K. 2014; 139: 487-507
  • Uranium Incorporation into Amorphous Silica ENVIRONMENTAL SCIENCE & TECHNOLOGY Massey, M. S., Lezama-Pacheco, J. S., Nelson, J. M., Fendor, S., Maher, K. 2014; 48 (15): 8636-8644

    Abstract

    High concentrations of uranium are commonly observed in naturally occurring amorphous silica (including opal) deposits, suggesting that incorporation of U into amorphous silica may represent a natural attenuation mechanism and promising strategy for U remediation. However, the stability of uranium in opaline silicates, determined in part by the binding mechanism for U, is an important factor in its long-term fate. U may bind directly to the opaline silicate matrix, or to materials such as iron (hydr)oxides that are subsequently occluded within the opal. Here, we examine the coordination environment of U within opaline silica to elucidate incorporation mechanisms. Precipitates (with and without ferrihydrite inclusions) were synthesized from U-bearing sodium metasilicate solutions, buffered at pH ∼ 5.6. Natural and synthetic solids were analyzed with X-ray absorption spectroscopy and a suite of other techniques. In synthetic amorphous silica, U was coordinated by silicate in a double corner-sharing coordination geometry (Si at ∼ 3.8-3.9 Å) and a small amount of uranyl and silicate in a bidentate, mononuclear (edge-sharing) coordination (Si at ∼ 3.1-3.2 Å, U at ∼ 3.8-3.9 Å). In iron-bearing synthetic solids, U was adsorbed to iron (hydr)oxide, but the coordination environment also contained silicate in both edge-sharing and corner-sharing coordination. Uranium local coordination in synthetic solids is similar to that of natural U-bearing opals that retain U for millions of years. The stability and extent of U incorporation into opaline and amorphous silica represents a long-term repository for U that may provide an alternative strategy for remediation of U contamination.

    View details for DOI 10.1021/es501064m

    View details for Web of Science ID 000340080600039

    View details for PubMedID 24984107

  • Olivine dissolution and carbonation under conditions relevant for in situ carbon storage CHEMICAL GEOLOGY Johnson, N. C., Thomas, B., Maher, K., Rosenbauer, R. J., Bird, D., Brown, G. E. 2014; 373: 93-105
  • URANIUM ISOTOPES IN SOILS AS A PROXY FOR PAST INFILTRATION AND PRECIPITATION ACROSS THE WESTERN UNITED STATES AMERICAN JOURNAL OF SCIENCE Maher, K., Ibarra, D. E., Oster, J. L., Miller, D. M., Redwine, J. L., Reheis, M. C., Harden, J. W. 2014; 314 (4): 821-857

    View details for DOI 10.2475/04.2014.01

    View details for Web of Science ID 000345105100001

  • Hydrologic Regulation of Chemical Weathering and the Geologic Carbon Cycle SCIENCE Maher, K., CHAMBERLAIN, C. P. 2014; 343 (6178): 1502-1504

    Abstract

    Earth's temperature is thought to be regulated by a negative feedback between atmospheric CO2 levels and chemical weathering of silicate rocks that operates over million-year time scales. To explain variations in the strength of the weathering feedback, we present a model for silicate weathering that regulates climatic and tectonic forcing through hydrologic processes and imposes a thermodynamic limit on weathering fluxes, based on the physical and chemical properties of river basins. Climate regulation by silicate weathering is thus strongest when global topography is elevated, similar to the situation today, and lowest when global topography is more subdued, allowing planetary temperatures to vary depending on the global distribution of topography and mountain belts, even in the absence of appreciable changes in CO2 degassing rates.

    View details for DOI 10.1126/science.1250770

    View details for Web of Science ID 000333471000045

    View details for PubMedID 24625927

  • Uranium isotopes in soils as a proxy for past infiltration and precipitation across the western United States AMERICAN JOURNAL OF SCIENCE Maher, K., Ibarra, D. E., Oster, J. L., Miller, D. M., Redwine, J. L., Reheis, M. C., Harden, J. C. 2014; 314: 821-857
  • Relationships between the transit time of water and the fluxes of weathered elements through the critical zone GEOCHEMISTRY OF THE EARTH'S SURFACE GES-10 Maher, K., Druhan, J. 2014; 10: 16-22
  • A model linking stable isotope fractionation to water flux and transit times in heterogeneous porous media GEOCHEMISTRY OF THE EARTH'S SURFACE GES-10 Druhan, J. L., Maher, K. 2014; 10: 179-188
  • Rise and fall of late Pleistocene pluvial lakes in response to reduced evaporation and precipitation: Evidence from Lake Surprise, California GEOLOGICAL SOCIETY OF AMERICA BULLETIN Ibarra, D. E., Egger, A. E., Weaver, K. L., Harris, C. R., Maher, K. 2014; 126 (11-12): 1387-1415

    View details for DOI 10.1130/B31014.1

  • Uranium incorporation into amorphous silica ENVIRONMENTAL SCIENCE AND TECHNOLOGY Massey, M., Lezama-Pacheco, J. S., Nelson, J. M., Fendorf, S., Maher, K. 2014; (in press)
  • A Teaching Exercise To Introduce Stable Isotope Fractionation of Metals into Geochemistry Courses JOURNAL OF CHEMICAL EDUCATION Weiss, D. J., Harris, C., Maher, K., Bullen, T. 2013; 90 (8): 1014-1017

    View details for DOI 10.1021/ed300370d

    View details for Web of Science ID 000323462900010

  • Environmental Speciation of Actinides INORGANIC CHEMISTRY Maher, K., Bargar, J. R., Brown, G. E. 2013; 52 (7): 3510-3532

    Abstract

    Although minor in abundance in Earth's crust (U, 2-4 ppm; Th, 10-15 ppm) and in seawater (U, 0.003 ppm; Th, 0.0007 ppm), light actinides (Th, Pa, U, Np, Pu, Am, and Cm) are important environmental contaminants associated with anthropogenic activities such as the mining and milling of uranium ores, generation of nuclear energy, and storage of legacy waste resulting from the manufacturing and testing of nuclear weapons. In this review, we discuss the abundance, production, and environmental sources of naturally occurring and some man-made light actinides. As is the case with other environmental contaminants, the solubility, transport properties, bioavailability, and toxicity of actinides are dependent on their speciation (composition, oxidation state, molecular-level structure, and nature of the phase in which the contaminant element or molecule occurs). We review the aqueous speciation of U, Np, and Pu as a function of pH and Eh, their interaction with common inorganic and organic ligands in natural waters, and some of the common U-containing minerals. We also discuss the interaction of U, Np, Pu, and Am solution complexes with common Earth materials, including minerals, colloids, gels, natural organic matter (NOM), and microbial organisms, based on simplified model system studies. These surface interactions can inhibit (e.g., sorption to mineral surfaces, formation of insoluble biominerals) or enhance (e.g., colloid-facilitated transport) the dispersal of light actinides in the biosphere and in some cases (e.g., interaction with dissimilatory metal-reducing bacteria, NOM, or Mn- and Fe-containing minerals) can modify the oxidation states and, consequently, the behavior of redox-sensitive light actinides (U, Np, and Pu). Finally, we review the speciation of U and Pu, their chemical transformations, and cleanup histories at several U.S. Department of Energy field sites that have been used to mill U ores, produce fissile materials for reactors and weapons, and store high-level nuclear waste from both civilian and defense operations, including Hanford, WA; Rifle, CO; Oak Ridge, TN; Fernald, OH; Fry Canyon, UT; and Rocky Flats, CO.

    View details for DOI 10.1021/ic301686d

    View details for Web of Science ID 000317094300009

    View details for PubMedID 23137032

  • Uranium comminution ages: Sediment transport and deposition time scales COMPTES RENDUS GEOSCIENCE DePaolo, D. J., Lee, V. E., Christensen, J. N., Maher, K. 2012; 344 (11-12): 678-687
  • Influence of eolian deposition and rainfall amounts on the U-isotopic composition of soil water and soil minerals GEOCHIMICA ET COSMOCHIMICA ACTA Oster, J. L., Ibarra, D. E., Harris, C. R., Maher, K. 2012; 88: 146-166
  • The role of fluid residence time and topographic scales in determining chemical fluxes from landscapes EARTH AND PLANETARY SCIENCE LETTERS Maher, K. 2011; 312 (1-2): 48-58
  • Evolution of hillslope soils: The geomorphic theater and the geochemical play APPLIED GEOCHEMISTRY Yoo, K., Weinman, B., Mudd, S. M., Hurst, M., Attal, M., Maher, K. 2011; 26: S149-S153
  • ISOTOPIC APPROACHES FOR QUANTIFYING THE RATES OF MARINE BURIAL DIAGENESIS REVIEWS OF GEOPHYSICS Fantle, M. S., MAHER, K. M., DePaolo, D. J. 2010; 48
  • The dependence of chemical weathering rates on fluid residence time EARTH AND PLANETARY SCIENCE LETTERS Maher, K. 2010; 294 (1-2): 101-110
  • Climatic and vegetation control on sediment dynamics during the last glacial cycle GEOLOGY Dosseto, A., Hesse, P. P., Maher, K., Fryirs, K., Turner, S. 2010; 38 (5): 395-398

    View details for DOI 10.1130/G30708.1

    View details for Web of Science ID 000277220900003

  • Uranyl-chlorite sorption/desorption: Evaluation of different U(VI) sequestration processes GEOCHIMICA ET COSMOCHIMICA ACTA Singer, D. M., Maher, K., Brown, G. E. 2009; 73 (20): 5989-6007
  • Combined ecological and geologic perspectives in ecosystem studies Preface CHEMICAL GEOLOGY Holloway, J. M., Ewing, S. A., Maher, K. 2009; 267 (1-2): 1-2
  • Chemical weathering of a marine terrace chronosequence, Santa Cruz, California. Part II: Solute profiles, gradients and the comparisons of contemporary and long-term weathering rates GEOCHIMICA ET COSMOCHIMICA ACTA White, A. F., Schulz, M. S., Stonestrom, D. A., Vivit, D. V., Fitzpatrick, J., Bullen, T. D., Maher, K., Blum, A. E. 2009; 73 (10): 2769-2803
  • The role of reaction affinity and secondary minerals in regulating chemical weathering rates at the Santa Cruz Soil Chronosequence, California GEOCHIMICA ET COSMOCHIMICA ACTA Maher, K., Steefel, C. I., White, A. F., Stonestrom, D. A. 2009; 73 (10): 2804-2831
  • Fluid-Rock Interaction: A Reactive Transport Approach THERMODYNAMICS AND KINETICS OF WATER-ROCK INTERACTION Steefel, C. I., Maher, K. 2009; 70: 485-532
  • Field evidence for strong chemical separation of contaminants in the Hanford vadose zone VADOSE ZONE JOURNAL Conrad, M. E., DePaolo, D. J., Maher, K., Gee, G. W., Ward, A. L. 2007; 6 (4): 1031-1041
  • Th-230-U dating of surficial deposits using the ion microprobe (SHRIMP-RG): A micro stratigraphic perspective QUATERNARY INTERNATIONAL Maher, K., Wooden, J. L., Paces, J. B., Miller, D. M. 2007; 166: 15-28
  • U-Sr isotopic speedometer: Fluid flow and chemical weathering rates in aquifers GEOCHIMICA ET COSMOCHIMICA ACTA Maher, K., DePaolo, D. J., Christensen, J. N. 2006; 70 (17): 4417-4435
  • Sediment transport time measured with U-series isotopes: Results from ODP North Atlantic drift site 984 EARTH AND PLANETARY SCIENCE LETTERS DePaolo, D. J., Maher, K., Christensen, J. N., McManus, J. 2006; 248 (1-2): 394-410
  • Dissolution rates and vadose zone drainage from strontium isotope measurements of groundwater in the Pasco Basin, WA unconfined aquifer JOURNAL OF HYDROLOGY Singleton, M. J., Maher, K., DePaolo, D. J., Conrad, M. E., Dresel, P. E. 2006; 321 (1-4): 39-58
  • The mineral dissolution rate conundrum: Insights from reactive transport modeling of U isotopes and pore fluid chemistry in marine sediments GEOCHIMICA ET COSMOCHIMICA ACTA Maher, K., Steefel, C. I., DePaolo, D. J., Viani, B. E. 2006; 70 (2): 337-363
  • Rates of silicate dissolution in deep-sea sediment: In situ measurement using U-234/U-238 of pore fluids GEOCHIMICA ET COSMOCHIMICA ACTA Maher, K., DePaolo, D. J., Lin, J. C. 2004; 68 (22): 4629-4648
  • Identifying the sources of subsurface contamination at the Hanford Site in Washington using high-precision uranium isotopic measurements ENVIRONMENTAL SCIENCE & TECHNOLOGY Christensen, J. N., Dresel, P. E., Conrad, M. E., Maher, K., DePaolo, D. J. 2004; 38 (12): 3330-3337

    Abstract

    In the mid-1990s, a groundwater plume of uranium (U) was detected in monitoring wells in the B-BX-BY Waste Management Area at the Hanford Site in Washington. This area has been used since the late 1940s to store high-level radioactive waste and other products of U fuel-rod processing. Using multiple-collector ICP source magnetic sector mass spectrometry, high-precision uranium isotopic analyses were conducted of samples of vadose zone contamination and of groundwater. The isotope ratios 236U/238U, 234U/238U, and 238U/235U are used to distinguish contaminant sources. On the basis of the isotopic data, the source of the groundwater contamination appears to be related to a 1951 overflow event at tank BX-102 that spilled high-level U waste into the vadose zone. The U isotopic variation of the groundwater plume is a result of mixing between contaminant U from this spill and natural background U. Vadose zone U contamination at tank B-110 likely predates the recorded tank leak and can be ruled out as a significant source of groundwater contamination, based on the U isotopic composition. The locus of vadose zone contamination is displaced from the initial locus of groundwater contamination, indicating that lateral migration in the vadose zone was at least 8 times greater than vertical migration. The time evolution of the groundwater plume suggests an average U migration rate of approximately 0.7-0.8 m/day showing slight retardation relative to a groundwater flow of approximately 1 m/day.

    View details for DOI 10.1021/es034700q

    View details for Web of Science ID 000222051400028

    View details for PubMedID 15260332

  • Evaporation effects on oxygen and hydrogen isotopes in deep vadose zone pore fluids at Hanford, Washington VADOSE ZONE JOURNAL DePaolo, D. J., Conrad, M. E., Maher, K., Gee, G. W. 2004; 3 (1): 220-232
  • Vadose zone infiltration rate at Hanford, Washington, inferred from Sr isotope measurements WATER RESOURCES RESEARCH Maher, K., DePaolo, D. J., Conrad, M. E., Serne, R. J. 2003; 39 (8)