Thomas Cronin, Ph.D.
Thomas Cronin is a Senior Geologist at the Florence Bascom Geoscience Center.
Dr. Cronin received his BA from Colgate University in Geology in 1972 and MA and PhD in Geology from Harvard University in 1974 and 1977.
Positions: National Research Council Post-doc at the USGS at the Museum of Natural History, Washington DC 1977-1978, research scientist USGS since 1978. NSF-sponsored visiting researcher at Shizuoka University, Japan (1991), lecturer Urbino (Italy) Summer School for Paleoclimatology Faculty (2009-2016), adjunct faculty Georgetown University’s Walsh School of Foreign Service (2005-present), White House Office of Science, Technology and Policy (OSTP) (1996-97).
US Geological Survey research in paleoclimatology, sea-level change, biostratigraphy, geochemistry and ecosystems; more than co-authored 200 scientific articles, more than 60 journals including Science, Nature, Nature Geoscience, Proceedings National Academy of Sciences, Geology, Geophysical Research Letters, Trends in Ecology and Evolution, and Quaternary Science Reviews. Numerous invited articles to proceedings volumes, handbooks & encyclopedias. Written two books, former co-editor of Global & Planetary Change, editorial boards for Journal of Micropaleontology, Marine Micropaleontology, Journal of Paleontology. Frequent manuscript reviews for international journals, proposals to National Science Foundation and other agencies.
In addition to work at OSTP, served on numerous USGS and interagency scientific committees and panels, contributing to USGS program development and informing decision-makers and the public. Published influential studies in the fields of micropaleontology, sea level and climate change, paleoceanography, and ecosystem history. Honors: Brady Medal (TMS London), Duke of Montefeltro Medal (USSP Urbino), Fellow, American Association for Advancement of Science, Wilmot H. Bradley lecture (Geological Society Washington), US Coast Guard Service Medal, AGU Citation for Excellence Reviewing, Bolin Climate Center Annual Lecturer (Stockholm), USGS Leadership, Meritorious Service, and Excellence Awards. Research widely reported in media including NY Times, National Geographic Society, New Scientist, Chesapeake Bay Journal, BBC, NPR, AP, and Fox News. Collaboration with major research institutions across the US, Europe and Asia, mentored numerous bachelors, masters and PhD students.
Current research focused on Land-Sea Linkages in the Arctic, Arctic paleoclimatology and sea-level change. Participated in four Arctic icebreaker research expeditions recovering sediment cores of the last million years of Arctic Ocean history. Work has influenced US Department of Homeland Security, US Coast Guard icebreaker planning, NOAA’s Arctic Program, and the International Ocean Drilling Program deep-sea coring program.
Science and Products
Ryder Glacier in northwest Greenland is shielded from warm Atlantic water by a bathymetric sill
Marine latitudinal diversity gradients, niche conservatism and out of the tropics and Arctic: Climatic sensitivity of small organisms
Interglacial paleoclimate in the Arctic
Holocene Sea-Level Variability from Chesapeake Bay Tidal Marshes
The benthic foraminifera cassidulina from the Arctic Ocean: Application to paleoceanography and biostratigraphy
Stratigraphic occurrences of sub-polar planktic foraminifera in pleistocene sediments on the Lomonosov Ridge, Arctic Ocean
The mighty Susquehanna—extreme floods in Eastern North America during the past two millennia
Remobilization of old permafrost carbon to Chukchi Sea sediments during the end of the last deglaciation
Late Holocene paleoceanography in the Chukchi and Beaufort Seas, Arctic Ocean, based on benthic foraminifera and ostracodes
Paleoclimate Records: Providing context and understanding of current Arctic change
A North American Hydroclimate Synthesis (NAHS) of the Common Era
Paleoceanographic perspectives on Arctic Ocean change
Science and Products
- Science
- Multimedia
- Publications
Filter Total Items: 128
Ryder Glacier in northwest Greenland is shielded from warm Atlantic water by a bathymetric sill
The processes controlling advance and retreat of outlet glaciers in fjords draining the Greenland Ice Sheet remain poorly known, undermining assessments of their dynamics and associated sea-level rise in a warming climate. Mass loss of the Greenland Ice Sheet has increased six-fold over the last four decades, with discharge and melt from outlet glaciers comprising key components of this loss. HereAuthorsMartin Jakobsson, Larry Mayer, Johan Nilsson, Christian Stranne, Brian Calder, Matthew O'Regan, J. Farrell, Thomas M. Cronin, Volker Bruchert, Julek Chawarski, Bjorn Eriksson, Jonas Fredriksson, Laura Gemery, Anna Glueder, Felicity A. Holmes, Kevin Jerram, Nina Kirchner, Alan Mix, Julia Muchowski, Abhay Prakash, Brendan Reilly, Brett Thornton, Adam Ulfsbo, Elizabeteh Weidner, Henning Akesson, Tamara Handl, Emelie Stahl, Lee-Gray Boze, Sam Reed, Gabriel West, June PadmanMarine latitudinal diversity gradients, niche conservatism and out of the tropics and Arctic: Climatic sensitivity of small organisms
AimThe latitudinal diversity gradient (LDG) is a consequence of evolutionary and ecological mechanisms acting over long history, and thus is best investigated with organisms that have rich fossil records. However, combined neontological‐palaeontological investigations are mostly limited to large, shelled invertebrates, which keeps our mechanistic understanding of LDGs in its infancy. This paper aiAuthorsWing‐Tung Ruby Chiu, Moriaki Yasuhara, Thomas M. Cronin, Gene Hunt, Laura Gemery, Chih‐Lin WeiInterglacial paleoclimate in the Arctic
Marine Isotope Stage 11 from ~424 to 374 ka experienced peak interglacial warmth and highest global sea level ~410–400 ka. MIS 11 has received extensive study on the causes of its long duration and warmer than Holocene climate, which is anomalous in the last half million years. However, a major geographic gap in MIS 11 proxy records exists in the Arctic Ocean where fragmentary evidence exists forAuthorsThomas M. Cronin, Katherine Keller, Jesse R. Farmer, Morgan Schaller, Matt O'Regan, Robert K. Poirier, Helen Coxall, Gary S. Dwyer, Henning Bauch, Ingalise G. Kindstedt, Martin Jakobsson, R. E. Marzen, Emiliano SantinHolocene Sea-Level Variability from Chesapeake Bay Tidal Marshes
We reconstructed the last 10,000 years of Holocene relative sea-level rise (RSLR) from sediment core records in near Chesapeake Bay, eastern U.S.A., including new marsh records from the Potomac and Rappahannock Rivers, Virginia. Results show mean RSLR rates of 2.6 mm yr-1 from 10 to 8 kilo-annum (ka) due to combined final ice-sheet melting during deglaciation and glacio-isostatic adjustment (GIAAuthorsThomas M. Cronin, Megan K. Clevenger, Neil E. Tibert, Tammy Prescott, Michael Toomey, J. Bradford Hubeny, Mark B. Abbott, Julia Seidenstein, Hannah Whitworth, Samuel R Fisher, Nick Wondolowski, Anna RueferThe benthic foraminifera cassidulina from the Arctic Ocean: Application to paleoceanography and biostratigraphy
We investigated the morphology, biostratigraphy, shell stable isotope composition and paleogeography of the common Arctic benthic foraminifera, Cassidulina teretis (Tappan 1951) (sometimes assigned to Islandiella (Nørvang 1958), for application to Quaternary paleoceanography. Cassidulina teretis, which has been studied by several generations of Arctic foraminiferal specialists, is used in ArcticAuthorsThomas M. Cronin, Julia Seidenstein, Katherine Keller, Kristin McDougall-Reid, Ana Reufer, Laura GemeryStratigraphic occurrences of sub-polar planktic foraminifera in pleistocene sediments on the Lomonosov Ridge, Arctic Ocean
Turborotalita quinqueloba is a species of planktic foraminifera commonly found in the sub-polar North Atlantic along the pathway of Atlantic waters in the Nordic seas and sometimes even in the Arctic Ocean, although its occurrence there remains poorly understood. Existing data show that T. quinqueloba is scarce in Holocene sediments from the central Arctic but abundance levels increase in sedimentAuthorsMatt O'Regan, Helen Coxall, Thomas M. Cronin, Richard Gyllencreutz, Martin Jakobsson, Stefanie Kaboth, Ludvig Löwemark, Steffen Wiers, Gabriel WestThe mighty Susquehanna—extreme floods in Eastern North America during the past two millennia
The hazards posed by infrequent major floods to communities along the Susquehanna River and the ecological health of Chesapeake Bay remain largely unconstrained due to the short length of streamgage records. Here we develop a history of high‐flow events on the Susquehanna River during the late Holocene from flood deposits contained in MD99‐2209, a sediment core recovered in 26 m of water from ChesAuthorsMichael Toomey, Meagan Cantwell, Steven Colman, Thomas M. Cronin, Jeffrey P. Donnelly, Liviu Giosan, Clifford Heil, Robert L. Korty, Marci E. Marot, Debra A. WillardRemobilization of old permafrost carbon to Chukchi Sea sediments during the end of the last deglaciation
Climate warming is expected to destabilize permafrost carbon (PF‐C) by thaw‐erosion and deepening of the seasonally thawed active layer and thereby promote PF‐C mineralization to CO2 and CH4. A similar PF‐C remobilization might have contributed to the increase in atmospheric CO2 during deglacial warming after the last glacial maximum. Using carbon isotopes and terrestrial biomarkers (Δ14C, δ13C, aAuthorsJannik Martens, Birgit Wild, Christof Pearce, Tommaso Tesi, August Andersson, Lisa Broder, Matt O'Regan, Martin Jakobsson, Martin Skold, Laura Gemery, Thomas M. CroninLate Holocene paleoceanography in the Chukchi and Beaufort Seas, Arctic Ocean, based on benthic foraminifera and ostracodes
Calcareous microfossil assemblages in late Holocene sediments from the western Arctic continental shelf provide an important baseline for evaluating the impacts of today’s changing Arctic oceanography. This study compares 14C-dated late Holocene microfaunal assemblages of sediment cores SWERUS-L2-2-PC1, 2-MC4 and 2-KL1 (57 mwd), which record the last 4200 years in the Herald Canyon (Chukchi Sea shAuthorsJulia Lynn Seidenstein, Thomas M. Cronin, Laura Gemery, Lloyd D Keigwin, Christof Pearce, Martin Jakobsson, Helen K Coxall, Emily A Wei, Neal W. DriscollPaleoclimate Records: Providing context and understanding of current Arctic change
At present, the Arctic Ocean is experiencing changes in ocean surface temperature and sea ice extent that are unprecedented in the era of satellite observations, which extend from the 1980s to the present (see sections 5c,d). To provide context for current changes, scientists turn to paleoclimate records to document and study anthropogenic influence and natural decadal and multidecadal climate varAuthorsEmily Osborne, Thomas M. Cronin, Jesse FarmerA North American Hydroclimate Synthesis (NAHS) of the Common Era
This study presents a synthesis of century-scale hydroclimate variations in North America for the Common Era (last 2000 years) using new age models of previously published multiple proxy-based paleoclimate data. This North American Hydroclimate Synthesis (NAHS) examines regional hydroclimate patterns and related environmental indicators, including vegetation, lake water elevation, stream flow andAuthorsJessica R. Rodysill, Lesleigh Anderson, Thomas M. Cronin, Miriam C. Jones, Robert S. Thompson, David B. Wahl, Debra A. Willard, Jason A. Addison, Jay R. Alder, Katherine H. Anderson, Lysanna Anderson, John A. Barron, Christopher E. Bernhardt, Steven W. Hostetler, Natalie M. Kehrwald, Nicole Khan, Julie N. Richey, Scott W. Starratt, Laura E. Strickland, Michael Toomey, Claire C. Treat, G. Lynn WingardByWater Resources Mission Area, Climate Research and Development Program, Energy Resources Program, Groundwater and Streamflow Information Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Florence Bascom Geoscience Center, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center, St. Petersburg Coastal and Marine Science CenterPaleoceanographic perspectives on Arctic Ocean change
The Arctic Ocean is presently experiencing changes in ocean temperature and sea ice extent that are unprecedented in the observational time period (satellite observations: 1979-Present). To provide context for the current changes, scientists turn to paleo records of past climate to document and study natural variability in the Arctic system. Paleoceanographic records that extend limited Arctic insAuthorsEmily Osborne, Thomas M. Cronin, Jesse Farmer - News