About

Ethan Grossman is a professor and the Michel T. Halbouty Chair at Texas A&M University in the College of Arts and Sciences, specializing in stable isotope geochemistry, clumped isotopes, and global change paleoclimates. His research involves the development and application of geochemical techniques, particularly oxygen and carbon isotope distributions, to address a broad range of geologic and societal problems. These include studying extreme climate events in Earth history, the linkages between the carbon cycle and climate, the thermal history of sedimentary basins, the origin of groundwater methane, and river dynamics in relation to climate change. Grossman's educational background includes a Ph.D. in Geochemistry from the University of Southern California, completed in 1982, and a B.S. in Geology from the State University of New York at Albany, earned in 1976. His contributions to the field have been recognized through numerous awards and honors, such as being elected a Fellow of the American Association for the Advancement of Science and the Geological Society of America, as well as receiving the Michel T. Halbouty Chair in Geology. His research has significantly advanced understanding of ocean temperatures through the Phanerozoic, paleoclimates, and basin thermal histories, among other areas, and he actively collaborates on projects related to isotope geosciences and water research.

Research topics

• Geology
• Oceanography
• Paleontology
• Computer Science
• Chemistry
• Geography
• Business
• Geochemistry
• Environmental resource management
• Database
• Environmental science
• Physical geography
• Earth science
• World Wide Web

Selected publications

• Biogeodynamic controls on Caribbean community structure during the formation of the Isthmus of Panama 

  2026-03-14

  articleOpen access

  The progressive restriction of seaways between the Caribbean and Pacific during the formation of the Isthmus of Panama fundamentally reorganized ocean circulation, biogeochemical cycling, and marine ecosystem structure across the tropical Americas. This tectonically driven reorganization provides a natural experiment for examining how long-term Earth system processes influence the structure, stability, and resilience of biological communities. The Bocas del Toro region of Caribbean Panama preserves a rich fossil record that captures ecological responses to these coupled physical and environmental changes.This study examines temporal variation in marine community composition and functional trait structure using fossil assemblages from four marine formations: Cayo Agua, Escudo de Veraguas, Old Bank, and Isla Colón, spanning approximately 6.0 to 0.43 Ma. The analyses integrate multiple taxonomic groups, including bivalves, gastropods, bryozoans, corals, and fishes, enabling comparison of ecological responses among organisms that differ in life habit, mobility, feeding strategy, tiering, and ecological function. By incorporating multiple clades with contrasting ecologies, this approach allows assessment of whether community change reflects reorganization within broadly conserved functional roles or more fundamental shifts in ecosystem structure.Community dynamics are quantified using a combination of model-based ordination, taxon-specific response analyses, and functional diversity metrics applied within a stratigraphic framework. These methods explicitly account for variation in sampling intensity and taxonomic richness, allowing ecological patterns to be distinguished from sampling effects. Biological patterns are evaluated alongside sedimentological and geochemical records to place community dynamics within their environmental context. Environmental–trait and environmental–taxon relationships are evaluated within a generalized linear latent variable modeling (GLLVM) framework to assess how changes in physical conditions, sedimentary processes, and geochemical variability influence community reorganization before, during, and after the formation of the Isthmus of Panama. Comparisons among contemporaneous formations allow local ecological responses to be distinguished from regionally coherent environmental signals.Overall, this study aims to clarify how long-term tectonic and oceanographic reorganization shapes marine ecosystem structure and stability, providing a stratigraphically grounded perspective on the links between Earth system processes and ecological dynamics over geological timescales.

  PublisherDOI

• Data for: Internal water and organic matter increase calcite clumped isotope reactivity

  Zenodo (CERN European Organization for Nuclear Research) · 2026-02-18

  datasetOpen accessSenior author

  This dataset accompanies the article "Internal water and organic matter increase calcite clumped isotope reactivity". 1. File: "Stable and Clumped Isotope Data.xlsx" This file includes stable and clumped isotope data for carbonate samples in heating experiments. Sheet 1: Report. This is the final reported data in the article. It shows the number of outliers removed from the raw dataset for each sample and the changes in δ¹⁸O, δ¹³C and Δ₄₇ after outlier elimination. Sheet 2: RawData_Samples. Raw sample data. Sheet 3: RawData_Standards. Raw standard data. Sheet 4: Evaluation. This shows outliers in δ¹⁸O, δ¹³C and Δ₄₇ for each sample detected by Peirce's criterion. Replicates flagged with "1" were eliminated. 2. File: "Data for Figures and Tables.xlsx" This file provides the H measurement data for USGS standards and cellulose and all the tables in the main paper and supplementary materials. Sheet 1: Fig. S1 TCEA H mass calibration. This contains the data used to create the H₂⁺ area vs. H mass calibration curve in Fig. S1. Sheet 2-6: These sheets correspond to the tables presented in the main paper and supplementary materials.

  PublisherDOI

• Data for: Internal water and organic matter increase calcite clumped isotope reactivity

  Zenodo (CERN European Organization for Nuclear Research) · 2026-02-18

  datasetOpen accessSenior author

  This dataset accompanies the article "Internal water and organic matter increase calcite clumped isotope reactivity". 1. File: "Stable and Clumped Isotope Data.xlsx" This file includes stable and clumped isotope data for carbonate samples in heating experiments. Sheet 1: Report. This is the final reported data in the article. It shows the number of outliers removed from the raw dataset for each sample and the changes in δ¹⁸O, δ¹³C and Δ₄₇ after outlier elimination. Sheet 2: RawData_Samples. Raw sample data. Sheet 3: RawData_Standards. Raw standard data. Sheet 4: Evaluation. This shows outliers in δ¹⁸O, δ¹³C and Δ₄₇ for each sample detected by Peirce's criterion. Replicates flagged with "1" were eliminated. 2. File: "Data for Figures and Tables.xlsx" This file provides the H measurement data for USGS standards and cellulose and all the tables in the main paper and supplementary materials. Sheet 1: Fig. S1 TCEA H mass calibration. This contains the data used to create the H₂⁺ area vs. H mass calibration curve in Fig. S1. Sheet 2-6: These sheets correspond to the tables presented in the main paper and supplementary materials.

  PublisherDOI

• Calcium isotopes across the Devonian–Mississippian Climate Transition

  Abstracts with programs - Geological Society of America · 2025-01-01

  article
  PublisherDOI

• The Devonian-Mississippian Climate Transition (DMCT): A clumped isotope study of a greenhouse-to-icehouse transition

  Abstracts with programs - Geological Society of America · 2025-01-01

  articleSenior author
  PublisherDOI

• Carbon and Oxygen Isotope Variations Within Carbonate Lithofacies: An Example from the Early Triassic Lower Mahil Formation (Upper Khuff-Equivalent) of Al Jabal Al-Akhdar, North Oman, Sultanate of Oman

  Advances in Science, Technology & Innovation/Advances in science, technology & innovation · 2025-01-01

  book-chapterSenior author
  PublisherDOI

• The Effect of Internal Water and Organic Matter on Carbonate Clumped Isotope Reactivity

  Abstracts with programs - Geological Society of America · 2025-01-01

  articleSenior author
  PublisherDOI

• Paleozoic temperatures: The oxygen isotope record

  Abstracts with programs - Geological Society of America · 2025-01-01

  article1st authorCorresponding
  PublisherDOI

• Erosion-driven Delayed Warming and Marine Stress prior to the end-Permian Mass Extinction

  Abstracts with programs - Geological Society of America · 2025-01-01

  article
  PublisherDOI

• Cold low-latitude Ordovician paleotemperatures may be in hot water

  Proceedings of the National Academy of Sciences · 2025-03-06 · 6 citations

  letterOpen access1st authorCorresponding
  PublisherOA PDFDOI

Recent grants

• Collaborative Research: Constraining rates of C-O bond reordering in biogenic calcite: Implications for clumped isotope thermometry

  NSF · $71k · 2012–2015

• Stable Isotope Record for Global and Regional Change in the Late Paleozoic

  NSF · $120k · 1993–1996

• Collaborative Research: Elements of an extinction: Exploring the delayed Caribbean extinction with stable isotopes and trace elements

  NSF · $246k · 2013–2017

• Constraining Late Paleozoic Climate, CO2 Levels, and Ice Sheet Volumes: Integration of Oxygen Isotopes with Climate and Ice Sheet Models

  NSF · $80k · 2001–2004

Frequent coauthors

• Aaron O’Dea

  21 shared

• Thomas E. Yancey

  Texas A&M University

  21 shared

• William F. Defliese

  University of Queensland

  18 shared

• Horng‐Sheng Mii

  University of Pisa

  12 shared

• Gregory Henkes

  11 shared

• K. Tao

  Texas A&M University

  11 shared

• Zeyang Sun

  Texas A&M University

  11 shared

• Wasif Zaheer

  Texas A&M University

  11 shared

Labs

• Geology & Geophysics Research LabPI

Education

• Ph.D., Geological Sciences

  University of Southern California

• B.S., Geology

  University at Albany State University of New York

Awards & honors

• Recognized as a 2021 "Exceptional Reviewer" for the GSA jour…
• Elected Fellow of the American Association for the Advanceme…
• Co-author of paper receiving the Smithsonian Secretary's 201…
• 2nd Place, Gordon I. Atwater Award for poster: Hendricks, Ya…
• Awarded Michel T. Halbouty Chair in Geology (2010, renewed i…