About

Dr. Robert F. Anderson is an Ewing Lamont Research Professor in Geochemistry at the Lamont-Doherty Earth Observatory and an Adjunct Professor in the Department of Earth and Environmental Sciences at Columbia University. He graduated summa cum laude from the University of Washington in 1975 with a double major in chemistry and oceanography, and earned his PhD in Chemical Oceanography from the Massachusetts Institute of Technology - Woods Hole Oceanographic Institution Joint Program in 1981. Since then, he has been affiliated with the Lamont-Doherty Earth Observatory, where he has advanced through various roles, including serving as Associate Director and overseeing the construction of the Comer building for the Geochemistry Division. His research focuses on the marine biogeochemical cycles of trace elements and isotopes, utilizing naturally occurring radionuclides to quantify rates of oceanic processes. Anderson has played a key role in international programs such as GEOSECS and GEOTRACES, which study ocean chemistry at a global scale and investigate the delivery and removal of trace elements, as well as their role as proxies for past ocean conditions. His work has contributed significantly to understanding ocean circulation, the carbon cycle, and paleoclimate, especially in relation to glacial-interglacial cycles and the Southern Ocean's role in climate regulation. Anderson has received numerous honors, including the C. C. Patterson Medal and fellowship in the Geochemical Society and the American Geophysical Union.

Research topics

• Geology
• Oceanography
• Paleontology
• Geochemistry
• Climatology
• Environmental chemistry
• Chemistry
• Mineralogy
• Environmental science

Selected publications

• 231Pa/230Th ratios in the Atlantic and Indian Oceans and their implications for the application of the ratios as an ocean circulation proxy

  Quaternary Science Reviews · 2025-06-04 · 1 citations

  articleOpen access
  PublisherDOI

• Reviews and syntheses: Review of proxies for low-oxygen paleoceanographic reconstructions

  Biogeosciences · 2025-02-18 · 17 citations

  articleOpen access

  Abstract. A growing body of observations has revealed rapid changes in both the total inventory and the distribution of marine oxygen over the latter half of the 20th century, leading to increased interest in extending oxygenation records into the past. The use of paleo-oxygen proxies has the potential to extend the spatial and temporal range of current records, constrain pre-anthropogenic baselines, provide datasets necessary to test climate models under different boundary conditions, and ultimately understand how ocean oxygenation responds beyond decadal-scale changes. This review seeks to summarize the current state of knowledge about proxies for reconstructing Cenozoic marine oxygen: sedimentary features, sedimentary redox-sensitive trace elements and isotopes, biomarkers, nitrogen isotopes, foraminiferal trace elements, foraminiferal assemblages, foraminiferal morphometrics, and benthic foraminiferal carbon isotope gradients. Taking stock of each proxy reveals some common limitations as the majority of proxies functions best at low-oxygen concentrations, and many reflect multiple environmental drivers. We also highlight recent breakthroughs in geochemistry and proxy approaches to constraining pelagic (in addition to benthic) oxygenation that are rapidly advancing the field. In light of both the emergence of new proxies and the persistent multiple driver problem, the need for multi-proxy approaches and data storage and sharing that adhere to the principles of findability, accessibility, interoperability, and reusability (FAIR) is emphasized. Continued refinements of proxy approaches and both proxy–proxy and proxy–model comparisons are likely to support the growing needs of both oceanographers and paleoceanographers interested in paleo-oxygenation records.

  PublisherOA PDFDOI

• Orbital Influences on Deep Ocean Oxygen Concentrations and Respired Carbon Storage

  Global Biogeochemical Cycles · 2025-06-01 · 2 citations

  article

  Abstract Quantitative records of bottom water oxygen (BWO) are critical for understanding deep ocean change through time. Because of the stoichiometric relationship between oxygen and carbon, BWO records provide insight into the physical and biogeochemical processes that control the air‐sea partitioning of both gases with important implications for climate over Quaternary glacial‐interglacial cycles. Here, we present new geochemical data sets from Ocean Discovery Program Site 1240 in the eastern equatorial Pacific to constrain paleoproductivity (Ba xs flux) and BWO using a multiproxy approach (aU, Mn/Al, Δδ 13 C, and U/Ba). This combination of approaches allows us to quantitatively identify changes in BWO and to parse local and basin‐wide contributions to the signal. We find that upwelling, not dust input, is responsible for driving productivity changes at the site. Changes in local carbon export are not the primary driver of changes in BWO, which instead reflect basin‐wide changes driven by processes in the Southern Ocean. Our BWO results provide direct evidence for the role of orbital precession and obliquity in driving deep sea respired carbon and oxygen concentrations. We find variations in BWO on the order of ∼50 μmol/kg that occur with ∼23 kyr periodicity during the substages of Marine Isotope Stage 5, and variations of ∼100 μmol/kg on glacial‐interglacial timescales. These findings have important implications for the role of insolation in driving deep ocean respired oxygen and carbon concentrations, and point to physical and biogeochemical changes in the Southern Ocean as key drivers of planetary‐scale carbon change.

  PublisherDOI

• Hydrothermal Plumes Act as a Regional Boundary Sink of ²³⁰Th in the Equatorial Pacific

  Global Biogeochemical Cycles · 2025-03-28 · 1 citations

  articleOpen access

  Abstract An important role in the cycling of marine trace elements is scavenging, their adsorption and removal from the water column by sinking particles. Boundary scavenging occurs when areas of strong particle flux drive preferential removal of the trace metals at locations of enhanced scavenging. Due to its uniform production and quick burial via scavenging, 230 Th is used to assess sedimentary mass fluxes; however, these calculations are potentially biased near regions where net lateral transport of dissolved 230 Th violates the assumption that the flux of particulate 230 Th to the seabed equals its rate of production in the water column. Here, we present a water column transect of dissolved 230 Th along 152° W between Alaska and Tahiti (GEOTRACES GP15), where we examine 230 Th profiles across multiple biogeochemical provinces and, novelly, the lateral transport of 230 Th to distal East Pacific Rise hydrothermal plumes. We observed a strong relationship between the slope of dissolved 230 Th concentration‐depth profiles and suspended particle matter inventory in the upper‐mid water column, reinforcing the view that biogenic particle mass flux sets the background 230 Th distribution in open ocean settings. We find that, instead of the region of enhanced particle flux around the equator, hydrothermal plumes act as a regional boundary sink of 230 Th. At 152° W, we found that the flux‐to‐production ratio, and thereby error in 230 Th‐normalized sediment flux, is between 0.80 and 1.50 for hydrothermal water, but the error is likely larger approaching the East Pacific Rise.

  PublisherOA PDFDOI

• Iron Fertilization of the North Pacific Did Not Drive Long‐Term Pliocene to Quaternary Cooling

  AGU Advances · 2025-08-29

  preprintOpen access

  Abstract While several hypotheses exist to explain the development of large‐scale perennial Northern Hemisphere ice sheets in the late Pliocene and early Pleistocene, the prevailing view is that a decline in atmospheric carbon dioxide (CO 2 ) drove this substantial change in late Neogene climate. However, the primary mechanism responsible for this reduction in CO 2 has yet to be fully explored. Mineral dust‐derived iron enhancement of ocean organic carbon production and export to the deep ocean and marine sediments has previously been invoked to explain reductions in atmospheric CO 2 on multiple timescales. Here we test the hypothesis that iron fertilization of the Pliocene subarctic North Pacific affected atmospheric CO 2 , and in turn drove the formation of Northern Hemisphere ice sheets. By compiling Pliocene dust and export productivity proxy data sets from across the North Pacific and then progressively filtering for the most reliable records, we find that there is no relationship between North Pacific dust inputs and export production in the Pliocene. Finally, we apply these new composites to broadly assess previously proposed drivers of Pliocene Asian dust dynamics as well as North Pacific Ocean circulation and biogeochemistry.

  PublisherDOI

• 20 years of an international collaborative research in marine geochemistry: the GEOTRACES program

  2025-03-26

  preprintOpen access1st author

  For the past 20 years, the GEOTRACES program (www.geotraces.org) has produced transformative insights into the cycling of trace elements and isotopes (TEIs) in the ocean. Be they bioactive elements essential for sea life (e.g., Fe, Ni, Cu, Zn…); contaminants (e.g., Pb, Hg); or tracers of processes like particle settling velocity (e.g. Th, Pa), source of matter (e.g. Nd, Pb isotopes) or deep vertical diffusion (e.g., Ra, Ac), TEI marine concentrations range from the nanomol to the attomole per litre, making their measurements particularly challenging. Thus, GEOTRACES encouraged international partnership while instilling a strong spirit of collaboration among scientists from more than 35 nations for more than two decades. Rigorous intercalibration efforts, standard definitions and capacity building are the cornerstone of the program to ensure that basin-scale analyses made by any researcher worldwide can be compared without doubt. The resulting high-quality data sets are synthesized and released every 4 years as intermediate data products (IDP), the fourth one being expected in 2025. Accessible to all, at no cost, these data sets resulted in the production of an online electronic atlas (www.egeotraces.org) including data from all ocean basins. GEOTRACES scientific missions and strategies are annually discussed within the « Scientific Steering Committee », the data quality assessed by the « Standard and Intercalibration Committee » while the data base building is managed by the « Data Management Committee ». The whole coordination and animation of these rich and diverse activities are ensured by the « International Project Office », hosted in Toulouse (France), which also largely contributes to the outreach and educational efforts of the program (www.geotraces.org/gted/).The talk will briefly describe this collaborative structure and illustrate its success with breakthroughs in the understanding of the oceanic cycling of key elements, such as the paradigm shift to a view of the marine Fe cycle where multiple sources contribute, including continental margins and hydrothermal plumes, so far strongly underestimated. The contribution of radionuclides, natural chronometers of processes, will also be underlined.

  PublisherDOI

• Multi‐Elemental Tracers in the Amerasian Basin Reveal Interlinked Biogeochemical and Physical Processes in the Arctic Ocean Upper Halocline

  Global Biogeochemical Cycles · 2025-04-01 · 2 citations

  articleOpen access

  Abstract The physical and biogeochemical properties of the western Arctic Ocean are rapidly changing, resulting in cascading shifts to the local ecosystems. The nutrient‐rich Pacific water inflow to the Arctic through the Bering Strait is modified on the Chukchi and East Siberian shelves by brine rejection during sea ice formation, resulting in a strong halocline (called the Upper Halocline Layer (UHL)) that separates the cold and relatively fresh surface layer from the warmer and more saline (and nutrient‐poor) Atlantic‐derived water below. Biogeochemical signals entrained into the UHL result from Pacific Waters modified by sediment and river influence on the shelf. In this synthesis, we bring together data from the 2015 Arctic U.S. GEOTRACES program to implement a multi‐tracer (dissolved and particulate trace elements, radioactive and stable isotopes, macronutrients, and dissolved gas/atmospheric tracers) approach to assess the relative influence of shelf sediments, rivers, and Pacific seawater contribution to the Amerasian Arctic halocline. For each element, we characterized their behavior as mixing dominated (e.g., dCu, dGa), shelf‐influenced (e.g., dFe, dZn), or a combination of both (e.g., dBa, dNi). Leveraging this framework, we assessed sources and sinks contributing to elemental distributions: shelf sediments (e.g., dFe, dZn, dCd, dHg), riverine sources, (e.g., dCu, dBa, dissolved organic carbon), and scavenging by particles originating on the shelf (e.g., dFe, dMn, dV, etc.). Additionally, synthesized results from isotopic and atmospheric tracers yielded tracer age estimates for the Upper Halocline ranging between 1 and 2 decades on a spatial gradient consistent with cyclonic circulation.

  PublisherDOI

• To Ba or Not to Ba: Evaluating Water Column Excess Particulate Barium as a Proxy for Water Column Respiration

  Global Biogeochemical Cycles · 2025-11-01

  article

  Abstract Particulate excess barium (pBa xs ), collected in situ, which is thought to exist as barite (BaSO 4 ), is potentially a powerful proxy of water column respiration. Here we use this proxy along the US GEOTRACES GA03 North Atlantic and GP16 East Pacific transects, comparing respiration rates derived from pBa xs distributions, using previously proposed algorithms, and respiration rates calculated using 230 Th‐normalized particulate organic carbon (POC) fluxes in the water column. Both transects traversed upwelling regimes, oxygen deficient zones (ODZs), near‐shore, and open‐ocean gyre stations, providing a more robust evaluation of the methodology than previous work. Respiration rates were estimated over two different depth intervals in the mesopelagic zone (100–500 m and 100–1,000 m). Generally, respiration rates were different ( p < 0.05) between biogeochemical provinces (i.e., gyre vs. Oxygen deficient zone stations) irrespective of method. Rates along GA03 were more difficult to establish using 230 Th‐normalized fluxes due to the absence of observed POC flux maxima in the top ∼0–100 m. Still, rate estimates using depth weighted average pBa xs concentrations and Th‐normalized POC fluxes in the 100–500 m interval agreed well within certain biogeochemical provinces: for example, at GP16 ODZ stations, average Th‐normalized POC respiration rate estimates were 3.3 ± 1.6 whereas pBa xs ‐based estimates were 2.9 ± 0.5 m mol C m −2 day −1 . Excess particulate Ba appears to be a reasonable proxy for water column POC respiration. We suggest that average excess pBa xs concentrations may be used as a method to calculate respiration rates in the 100–500 m depth interval if other methods are not available.

  PublisherDOI

• Supplementary material to "Reviews and syntheses: Review of proxies for low-oxygen paleoceanographic reconstructions "

  2024-01-09

  preprintOpen access

  Ca. Scalindua profunda' anammox hypoxia/anoxia, O 2 <20µmol

  PublisherDOI

• Chemical tracers of scavenging, particle dynamics, and sedimentation processes

  Treatise on Geochemistry · 2024-01-31 · 2 citations

  book-chapter1st authorCorresponding
  PublisherDOI

Recent grants

• Collaborative Research: Changes in Ocean Circulation, Productivity & Carbon Cycle during Heinrich Events

  NSF · $291k · 2006–2010

• Collaborative Research: U.S. GEOTRACES Pacific Section: Analysis of 230Th, 232Th and 231Pa

  NSF · $690k · 2013–2017

• Support for the U. S. GEOTRACES Project Office

  NSF · $990k · 2011–2016

• Radionuclide Ratios as Proxies of Particle Flux

  NSF · $448k · 1991–1995

• Water Mass Structure and Bottom Water Formation in the Ice-age Southern Ocean

  NSF · $278k · 2016–2020

Frequent coauthors

• Martin Q. Fleisher

  Lamont-Doherty Earth Observatory

  229 shared

• Gisela Winckler

  Columbia University

  193 shared

• Frank J. Pavia

  103 shared

• Christopher T. Hayes

  99 shared

• Jerry F McManus

  Columbia University

  71 shared

• Samuel L. Jaccard

  University of Lausanne

  61 shared

• Sascha Serno

  61 shared

• Zanna Chase

  University of Tasmania

  56 shared

Education

• PhD, Chemistry

  Woods Hole Oceanographic Institution

  1981

Awards & honors

• 2015 Ludwick Lecture, Old Dominion University
• 2014 Inducted as fellow of the Geochemical Society
• 2010 C. C. Patterson Medal, Geochemical Society (environment…
• 2010 Sverdrup Lecture, Ocean Sciences Section of the America…
• 2005 A.G. Huntsman Award for Excellence in the Marine Scienc…