About

Frankie Pavia is an isotope geochemist who is interested in devising and applying new techniques to study the modern and past evolution of Earth’s climate and carbon cycle. His research uses radioactive isotopic tracers as fingerprints of how quickly Earth system processes occur. Frankie arrived at the University of Washington in early 2024 and is building a research program to study many facets of Earth’s climate, including particle aggregation processes and carbon degradation in seawater, changes in sea ice coverage and ice sheet melt in the geologic past, and the weathering of mantle rocks at the seafloor.

Research topics

• Geology
• Paleontology
• Oceanography
• Environmental chemistry
• Geochemistry
• Mineralogy

Selected publications

• Carbon dioxide removal by enhanced weathering on American green clay tennis courts

  Applied Geochemistry · 2026-02-19

  article1st authorCorresponding
  PublisherDOI

• Exploring the Cenozoic Earth system with extraterrestrial ³ He

  2026-04-08

  articleOpen access

  Abstract. A key method for contextualizing climate today and into the future is to draw upon the past. Marine sediments accumulating at the bottom of the ocean serve as the only continuous archive of Earth's climate history spanning tens of millions of years. From the earliest studies of marine sediments, reconstructed changes in the inputs of sedimentary constituents such as volcanic glass, ice-rafted debris, particulates carried by rivers, desert dust, organic and inorganic remnants of organisms and biological process, and even extraterrestrial material, have been used to discern past environmental conditions. Specifically, it is the rate at which these different components of sediments from the bottom of the ocean accrue over time that can provide unique and important insight into how Earth system dynamics operated in the near and distant past. Traditional techniques for quantifying sediment mass accumulation rates (MARs) contain numerous complexities that can lead to erroneous MAR determinations. Constant flux proxies (CFPs), particularly extraterrestrial 3He (3HeET) delivered in interplanetary dust particles from space, are underutilized geochemical tools that alleviate these issues as long as key assumptions can be constrained. In this perspective, we review CFP 3HeET as a CFP and outline its benefit for understanding Cenozoic climate beyond the Quaternary. Ultimately, we suggest that the application of 3HeET is valuable for providing the broader paleoclimate and paleoceanography communities with accurate records of Cenozoic Earth system change from a MAR perspective.

  PublisherDOI

• Cosmic dust reveals dynamic shifts in central Arctic sea-ice coverage over the past 30,000 years

  Science · 2025-11-06 · 1 citations

  article1st authorCorresponding

  Arctic sea-ice loss affects biological productivity, sustenance in coastal communities, and geopolitics. Forecasting these impacts requires mechanistic understanding of how Arctic sea ice responds to climate change, but this is limited by scarce long-term records. We present continuous 30,000-year reconstructions of sea-ice coverage from the Arctic Ocean based on measurements of two isotopes, thorium-230 and extraterrestrial helium-3, whose burial ratio changes with sea-ice coverage. We found that the central Arctic was perennially covered by sea ice during the last glaciation. Sea-ice cover retreated during the deglaciation approximately 15,000 years ago, culminating in seasonal sea-ice coverage in the warm early Holocene, before ice coverage increased into the late Holocene. Sea-ice changes closely correlate with biological nutrient consumption, supporting projections of a nutrient-starved central Arctic Ocean with continued sea-ice loss.

  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

  articleSenior author

  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

• The Marine Sediment Archive of Hydrothermal Activity

  Geophysical monograph · 2025-11-04

  otherSenior author
  PublisherDOI

• Corrigendum to “Carbonate dissolution fluxes in deep-sea sediments as determined from in situ porewater profiles in a transect across the saturation horizon” [Geochim. Cosmochim. Acta. 390 (2025) 145–159]

  Geochimica et Cosmochimica Acta · 2025-03-22

  erratumOpen access
  PublisherDOI

• Biogenic Si Cycling Along the Cocos Ridge: Differences between in Situ and Ex Situ Extracted Pore Waters Imply Rapid Rates of Dissolved Si Uptake Upon Core Recovery

  SSRN Electronic Journal · 2025-01-01

  preprintOpen access
  PublisherDOI

• Evaluating the Behavior of 230Th and 3He Constant-Flux Proxies Across a Carbonate Preservation Gradient in the Cocos Ridge

  2025-10-19

  preprint
  PublisherDOI

• Application of a novel inorganic proxy to reconstruct Arctic sea-ice coverage during warm periods

  2025-03-25

  preprintOpen accessSenior author

  The Arctic region is warming nearly four times faster than the rest of the planet, coinciding with a rapid reduction in Arctic sea-ice. Sea-ice decline has broad ramifications for both marine and human life: reductions in sea-ice drive changes in primary productivity and fish populations, amplify coastal erosion due to increased wave action, and make previously inaccessible waterways open for shipping, resource exploration, and military activity. Observations from the geologic past serve as critical benchmarks for constraining climate model projections of future sea-ice decline. However, current proxies of past sea-ice coverage produce conflicting results and are limited by their basis in ecosystem structure and biomarker preservation. In order to improve model predictions for the rate of future sea-ice decline and validate existing sea-ice data, I will develop a new inorganic proxy based on the coupled behavior of extraterrestrial helium-3 and excess thorium-230 and apply the proxy to the two most recent geologically warm periods, the Early Holocene and the Last Interglacial. Preliminary data suggests that these two paired isotopes reconstruct the behavior of perennial and seasonal sea-ice within the Arctic Ocean over the past 50,000 years. To understand the connection between sea-ice and biological productivity, I will combine my sea-ice reconstructions with reconstructions of nutrient consumption within the surface Arctic Ocean based on the nitrogen isotopic composition of foraminifera-bound organic matter. I will use my results to refine climate model projections for the timescales and biological implications of future sea ice decline in the Arctic region.

  PublisherDOI

• Microbial Cycling of Sulfur and Other Redox‐Sensitive Elements in Porewaters of San Clemente Basin, California, and Cocos Ridge, Costa Rica

  Geobiology · 2025-01-01 · 2 citations

  article

  The microbial recycling of organic matter in marine sediments depends upon electron acceptors that are utilized based on availability and energetic yield. Since sulfate is the most abundant oxidant once oxygen has been depleted, the sulfide produced after sulfate reduction becomes an important electron donor for autotrophic microbes. The ability of sulfide to be re-oxidized through multiple metabolic pathways and intermediates with variable oxidation states prompts investigation into which species are preferentially utilized and what are the factors that determine the fate of reduced sulfur species. Quantifying these sulfur intermediates in porewaters is a critical first step towards achieving a more complete understanding of the oxidative sulfur cycle, yet this has been accomplished in very few studies, none of which include oligotrophic sedimentary environments in the open ocean. Here we present profiles of porewater sulfur intermediates from sediments underlying oligotrophic regions of the ocean, which encompass about 75% of the ocean's surface and are characterized by low nutrient levels and productivity. Aiming at addressing uncertainties about if and how sulfide produced by the degradation of scarce sedimentary organic matter plays a role in carbon fixation in the sediment, we determine depth profiles of redox-sensitive metals and sulfate isotope compositions and integrate these datasets with 16S rRNA microbial community composition data and solid-phase sulfur concentrations. We did not find significant correlations between sulfur species or trace metals and specific sulfur cycling taxa, which suggests that microorganisms in pelagic and oxic sediments may be generalists utilizing flexible metabolisms to oxidize organic matter through different electron acceptors.

  PublisherDOI

Frequent coauthors

• Robert F. Anderson

  103 shared

• Sebastián M. Vivancos

  Columbia University

  47 shared

• Gisela Winckler

  Columbia University

  43 shared

• Martin Q. Fleisher

  Lamont-Doherty Earth Observatory

  40 shared

• Hai Cheng

  Xi'an Jiaotong University

  31 shared

• Jennifer L. Middleton

  Lamont-Doherty Earth Observatory

  30 shared

• Yanbin Lu

  Northwest University

  28 shared

• Matthieu Roy‐Barman

  Commissariat à l'Énergie Atomique et aux Énergies Alternatives

  27 shared

Education

• Ph.D., Geochemistry

  Lamont-Doherty Earth Observatory, Columbia University

  2019

• M.A.

  Lamont-Doherty Earth Observatory, Columbia University

  2016

• B.A. , Earth and Environmental Sciences & Chemistry

  Columbia University

  2014