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
The Holocene dynamics of Ryder Glacier and ice tongue in north Greenland
Mg/Ca ratios in ostracode genera Sarsicytheridea and Paracyprideis: A potential paleotemperature proxy for Arctic and subarctic continental shelf and slope waters
Arctic Ocean stratification set by sea level and freshwater inputs since the last ice age
Biogeography and ecology of Ostracoda in the U.S. northern Bering, Chukchi, and Beaufort Seas
Foreward: The paleoclimatic and paleobiogeographic significance of the Tjörnes Basin, Northern Iceland
Remobilization of old permafrost carbon to Chukchi Sea sediments during the end of the last deglaciation
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
Sea Level and Storm Hazards: Past and Present
Land-Sea Linkages in the Arctic
Science Summary Sea-Level Rise and Chesapeake Bay
Science and Products
Filter Total Items: 120
The Holocene dynamics of Ryder Glacier and ice tongue in north GreenlandThe northern sector of the Greenland Ice Sheet is considered to be particularly susceptible to ice mass loss arising from increased glacier discharge in the coming decades. However, the past extent and dynamics of outlet glaciers in this region, and hence their vulnerability to climate change, are poorly documented. In the summer of 2019, the Swedish icebreaker Oden entered the previously uncharte
Mg/Ca ratios in ostracode genera Sarsicytheridea and Paracyprideis: A potential paleotemperature proxy for Arctic and subarctic continental shelf and slope watersWe evaluate the potential utility of Mg/Ca ratios in the sublittoral ostracode genera Sarsicytheridea and Paracyprideis as a paleotemperature proxy for continental shelf and upper slope waters of the Arctic Ocean and adjacent seas. Using sediment core-top and surface sediment samples, the shells of three species, S. bradii, S. punctillata, and P. pseudopunctillata, were analyzed from Arctic Ocean
Arctic Ocean stratification set by sea level and freshwater inputs since the last ice ageSalinity-driven density stratification of the upper Arctic Ocean isolates sea-ice cover and cold, nutrient-poor surface waters from underlying warmer, nutrient-rich waters. Recently, stratification has strengthened in the western Arctic but has weakened in the eastern Arctic; it is unknown if these trends will continue. Here we present foraminifera-bound nitrogen isotopes from Arctic Ocean sedimen
Biogeography and ecology of Ostracoda in the U.S. northern Bering, Chukchi, and Beaufort SeasOstracoda (bivalved Crustacea) comprise a significant part of the benthic meiofauna in the Pacific-Arctic region, including more than 50 species, many with identifiable ecological tolerances. These species hold potential as useful indicators of past and future ecosystem changes. In this study, we examined benthic ostracodes from nearly 300 surface sediment samples, >34,000 specimens, from three re
Foreward: The paleoclimatic and paleobiogeographic significance of the Tjörnes Basin, Northern IcelandSince the mid-19th century, geologists and paleontologists have recognized the scientific importance and unique nature of the richly fossiliferous sediments exposed along the Tjörnes Peninsula in Northern Iceland. In the following century and a half, Tjörnes has attracted the attention of an international “who’s who” in Cenozoic paleontology, as well as many paleoclimatologists unraveling the com
Remobilization of old permafrost carbon to Chukchi Sea sediments during the end of the last deglaciationClimate 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, a
Ryder Glacier in northwest Greenland is shielded from warm Atlantic water by a bathymetric sillThe 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. Here
Marine latitudinal diversity gradients, niche conservatism and out of the tropics and Arctic: Climatic sensitivity of small organismsAimThe 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 ai
Interglacial paleoclimate in the ArcticMarine 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 for
Holocene Sea-Level Variability from Chesapeake Bay Tidal MarshesWe 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 (GIA
The benthic foraminifera cassidulina from the Arctic Ocean: Application to paleoceanography and biostratigraphyWe investigated the morphology, biostratigraphy, shell stable isotope composition and paleogeography of the common Arctic benthic foraminifera, Cassidulina teretis (Tappan 1951) (sometimes assigned to Islandiella (NÃ¸rvang 1958), for application to Quaternary paleoceanography. Cassidulina teretis, which has been studied by several generations of Arctic foraminiferal specialists, is used in Arctic
Stratigraphic occurrences of sub-polar planktic foraminifera in pleistocene sediments on the Lomonosov Ridge, Arctic OceanTurborotalita 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 sediment
Sea Level and Storm Hazards: Past and PresentSea level and Storm Hazards: Past and Present is a multidisciplinary study of past changes in sea level. Prehistoric shorelines can be used as a baseline for current and future sea level changes under warmer-than-present climate. Emphasis is placed on looking at sea levels during warm periods of the last 500,000 years as well as how base level changes increase the risk of coastal inundation during...
Land-Sea Linkages in the ArcticThe Arctic is undergoing historically unprecedented changes in weather, sea ice, temperature and ecosystems. These changes have led to greater coastal erosion, greater export of freshwater, and changes to marine and terrestrial ecosystems, habitats, and productivity, among other trends. Meanwhile, many believe the Arctic “amplifies” large climate changes during both warm periods and ice ages and...
Science Summary Sea-Level Rise and Chesapeake BaySea-Level Rise and Chesapeake Bay