Julie Richey is a Research Geologist at the St. Petersburg Coastal and Marine Science Center.
Paleoclimate and Environmental Change
Establishing a baseline of natural climate variability over the past 2,000 years is essential to accurately predicting regional responses to anthropogenic climate change. My research focus is reconstructing temperature and hydroclimatic variability in the Gulf of Mexico/Subtropical Atlantic Ocean using a broad range of different paleoclimate archives. In addition to generating proxy-based paleoclimate records, I am working on proxy development and calibration studies to improve our ability to quantify past changes in temperature, salinity and precipitation in both terrestrial and marine environments.
Coral Paleoclimate
Research Interests
- Using stable isotopes and trace elements to reconstruct climate from coral skeletons
- Investigating the effect of water quality and coral ecology on geochemical proxies
Field Sites
- US Virgin Islands
- Dry Tortugas National Park
- Florida Keys Reef Tract
Project web page: https://www.usgs.gov/centers/spcmsc/science/coral-reef-ecosystem-studies-crest
Holocene Paleoclimate in the Gulf of Mexico
Project web page: https://www.usgs.gov/centers/spcmsc/science/climate-and-environmental-change-gulf-mexico-and-caribbean
Research Interests
- Paleoclimate Reconstruction from Marine and Lake Sediments
- Coral Reefs as Climate Archives
- Paleoceanographic Proxy Calibration
Field Sites
- Garrison Basin (Gulf of Mexico)
- Fisk Basin (Gulf of Mexico)
- Pigmy Basin (Gulf of Mexico)
- Sediment Trap Site (Gulf of Mexico)
Education and Certifications
Ph. D. - Marine Geology (2010), Univ. of South Florida, College of Marine Science
M.S. - Marine Geology (2007), Univ. of South Florida, College of Marine Science
B.S. - Geological Sciences/Biological Sciences (2004), The Ohio State Univ.
Science and Products
Reconstructing Ocean Circulation & Hydroclimate in the Subtropical Atlantic
Coral Reef Ecosystem Studies (CREST)
Reef History and Climate Change
Paleoclimate Reconstruction from Marine and Lake Sediments
Paleoceanographic Proxy Calibration
Climate and Environmental Change in the Gulf of Mexico and Caribbean
Globorotalia truncatulinoides Trace Element Geochemistry (Barium, Magnesium, Strontium, Manganese, and Calcium) From the Gulf of Mexico Sediment Trap
Local Radiocarbon Reservoir Age (Delta-R) Variability from the Nearshore and Open-Ocean Environments of the Florida Keys Reef Tract During the Holocene and Associated U-Series and Radiocarbon Data
Radiocarbon Dates and Foraminiferal Geochemistry Data for Sediment Core Collected from Garrison Basin, Gulf of Mexico
Foraminiferal Mg/Ca Data from IODP Sediment Core U1446
Globigerinoides ruber Sediment Trap Data in the Gulf of Mexico
Sr/Ca and Linear Extension Data for Five Modern O. faveolata Colonies from Dry Tortugas National Park, Florida, USA
Globorotalia truncatulinoides Sediment Trap Data in the Gulf of Mexico
GDGT and Alkenone Flux in the Northern Gulf of Mexico
Multi-species Coral Sr/Ca Based Sea-Surface Temperature Reconstruction Data Using Orbicella faveolata and Siderastrea siderea from Dry Tortugas National Park, Florida
Barium enrichment in the non-spinose planktic foraminifer, Globorotalia truncatulinoides
Contrasting Common Era climate and hydrology sensitivities from paired lake sediment dinosterol hydrogen isotope records in the South Pacific Convergence Zone
Holocene evolution of sea-surface temperature and salinity in the Gulf of Mexico
Remote and local drivers of Pleistocene South Asian summer monsoon precipitation: A test for future predictions
Imprint of regional oceanography on foraminifera of eastern Pacific Coral Reefs
PaCTS 1.0: A crowdsourced reporting standard for paleoclimate data
Considerations for Globigerinoides ruber (white and pink) paleoceanography: Comprehensive insights from a long‐running sediment trap
Reconstructing precipitation in the tropical South Pacific from dinosterol 2H/1H ratios in lake sediment
Quantifying uncertainty in Sr/Ca-based estimates of SST from the coral Orbicella faveolata
Environmental controls on the geochemistry of Globorotalia truncatulinoides in the Gulf of Mexico: Implications for paleoceanographic reconstructions
A North American Hydroclimate Synthesis (NAHS) of the Common Era
Pronounced centennial-scale Atlantic Ocean climate variability correlated with Western Hemisphere hydroclimate
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Science
Reconstructing Ocean Circulation & Hydroclimate in the Subtropical Atlantic
Changes in rainfall patterns as a result of anthropogenic climate change are already having large ecological and socioeconomic impacts across the globe. Increases in flood damage, wildfire damage, and agricultural losses can all be attributed to anomalous rainfall events and prolonged droughts across the United States in recent years. Additionally, Atlantic Ocean circulation, which has a large...Coral Reef Ecosystem Studies (CREST)
The specific objectives of this project are to identify and describe the processes that are important in determining rates of coral-reef construction. How quickly the skeletons of calcifying organisms accumulate to form massive barrier-reef structure is determined by processes of both construction (how fast organisms grow and reproduce) and destruction (how fast reefs break down by mechanical...Reef History and Climate Change
Ecosystem-wide study of seafloor erosion, changing coastal water depths, and effects on coastal storm and wave impacts along the Florida Keys Coral Reef Tract in South Florida.Paleoclimate Reconstruction from Marine and Lake Sediments
Instrumental measurements of climate variables (e.g., precipitation, temperature, ocean circulation, etc.) are only available over the past century or less. In order to quantify the rate and magnitude of natural climate variability going back in time beyond the 20th century, scientists rely on paleoclimate reconstructions.Paleoceanographic Proxy Calibration
A sediment trap time series in the northern Gulf of Mexico is used to better assess the control of environmental variables (e.g., temperature and salinity) on the flux of both microfossils and molecular fossils to the sediments. The information gained from sediment trap studies is used to develop better proxy-based estimates of past oceanographic conditions from analyses of microfossils and...Climate and Environmental Change in the Gulf of Mexico and Caribbean
This project documents paleoceanographic, climatic, and environmental changes in the Gulf of Mexico and adjacent land areas over the last 10,000 years. The paleoenvironmental data is used to determine rates of change in the past, and to better understand both the natural and anthropogenic factors that contribute to climate variability on inter-annual to millennial timescales. - Data
Globorotalia truncatulinoides Trace Element Geochemistry (Barium, Magnesium, Strontium, Manganese, and Calcium) From the Gulf of Mexico Sediment Trap
Observations of elevated barium-to-calcium ratio (Ba/Ca) in Globorotalia truncatulinoides have been attributed to contaminant phases, deep calcification depth and diagenetic processes. U.S. Geological Survey (USGS) scientists and their collaborators investigated intra- and inter-test Ba/Ca variability in the non-spinose planktic foraminifer, G. truncatulinoides, from a sediment trap time series (Local Radiocarbon Reservoir Age (Delta-R) Variability from the Nearshore and Open-Ocean Environments of the Florida Keys Reef Tract During the Holocene and Associated U-Series and Radiocarbon Data
Holocene-aged corals from reef cores collected throughout the Florida Keys reef tract (FKRT; Fig. 1) were dated using a combination of U-series and radiocarbon techniques to quantify the millennial-scale variability in the local radiocarbon reservoir age (delta-R) of the shallow water environments of south Florida. delta-R provides a measure of the deviation of local radiocarbon concentrations ofRadiocarbon Dates and Foraminiferal Geochemistry Data for Sediment Core Collected from Garrison Basin, Gulf of Mexico
Stable oxygen and carbon isotope composition (delta18O and delta13C) and magnesium-to-calcium (Mg/Ca) ratios were measured in the tests of planktic foraminiferal species, Globigerinoides ruber (white variety), in a northwestern Gulf of Mexico sediment core 2010-GB2-GC1 collected from the Garrison Basin (26.67 degrees N, 93.92 degrees W) at a water depth of 1776 meters (m), aboard the R/V Cape HattForaminiferal Mg/Ca Data from IODP Sediment Core U1446
In 2019 the magnesium-to-calcium (Mg/Ca) ratios were measured in the tests of planktic foraminiferal species, Globigerinoides ruber (white variety), in a subset of samples from Integrated Ocean Drilling Program (IODP) sediment core U1146 from the Bay of Bengal drilled November 2014 to January 2015. For further information regarding data collection and/or processing methods, refer to the associatedGlobigerinoides ruber Sediment Trap Data in the Gulf of Mexico
We present results here from a high-resolution (1-2 weeks) and long-running sediment trap time series from the northern Gulf of Mexico which allows for a detailed assessment of the seasonal distribution, size, morphological variability and geochemistry of co-occurring pink and white chromotypes of Globigerinoides ruber. The flux of both chromotypes is highly correlated, and both represent mean annSr/Ca and Linear Extension Data for Five Modern O. faveolata Colonies from Dry Tortugas National Park, Florida, USA
Strontium/Calcium (Sr/Ca) ratios act as a proxy for sea surface temperature (SST) in the skeletons of aragonite producing organisms, such as massive corals. The Sr/Ca-SST proxy shows promise when applied to single Orbicella faveolata colonies in the Atlantic/Caribbean regions, but it is currently unknown how well the Sr/Ca-SST proxy performs between colonies of this species. It is necessary to undGloborotalia truncatulinoides Sediment Trap Data in the Gulf of Mexico
Modern observations of planktic foraminifera from sediment trap studies help to constrain the regional ecology of paleoceanographically valuable species. Results from a weekly-resolved sediment trap time series (2008-2014) in the northern Gulf of Mexico demonstrate that 92% of Globorotalia truncatulinoides flux occurs in winter (January, February, and March), and that encrusted and non-encrusted iGDGT and Alkenone Flux in the Northern Gulf of Mexico
This dataset is a weekly to bi-weekly resolution 4-year time series (2010-2014) of GDGT and alkenone flux in the northern Gulf of Mexico. The TEX86 and U indices are also included, which are sea surface temperature proxies based on the distribution of GDGTs and alkenones, respectively. For further information regarding data collection and/or processing methods refer to Richey and Tierney (2016).Multi-species Coral Sr/Ca Based Sea-Surface Temperature Reconstruction Data Using Orbicella faveolata and Siderastrea siderea from Dry Tortugas National Park, Florida
New sub annual and mean annual Sr/Ca records from two species of massive coral, Orbicella faveolata (coral B3) and Siderastrea siderea (coral CG2), from the Dry Tortugas National Park, FL (DRTO). Both corals have well-constrained chronologies, with coral B3 ranging from 1893-2008 and coral CG2 ranging from 1837-2012. We combine these new records with published Sr/Ca data from three additional S. s - Publications
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Barium enrichment in the non-spinose planktic foraminifer, Globorotalia truncatulinoides
Observations of elevated barium-to-calcium ratios (Ba/Ca) in Globorotalia truncatulinoides have been attributed to contaminant phases, deep calcification depth and diagenetic processes. Here we investigate intra- and inter-test Ba/Ca variability in the non-spinose planktic foraminifer, G. truncatulinoides, from a sediment trap time series in the northern Gulf of Mexico to gain insights into the enContrasting Common Era climate and hydrology sensitivities from paired lake sediment dinosterol hydrogen isotope records in the South Pacific Convergence Zone
Hydroclimate on ‘Uvea (Wallis et Futuna) is controlled by rainfall associated with the South Pacific Convergence Zone (SPCZ), the southern hemisphere's largest precipitation feature. To extend the short observational precipitation record, the hydrogen isotopic composition of the algal lipid biomarker dinosterol (δ2Hdinosterol) was measured in sediment cores from two volcanic crater lakes on ‘Uvea.Holocene evolution of sea-surface temperature and salinity in the Gulf of Mexico
Flows into and out of the Gulf of Mexico (GoM) are integral to North Atlantic ocean circulation, and help facilitate poleward heat transport in the Western Hemisphere. The GoM also serves as a key source of moisture for much of North America. Modern patterns of sea-surface temperature (SST) and salinity in the GoM are influenced by the Loop Current, its eddy-shedding dynamics, and the ensuing inteRemote and local drivers of Pleistocene South Asian summer monsoon precipitation: A test for future predictions
South Asian precipitation amount and extreme variability are predicted to increase due to thermodynamic effects of increased 21st-century greenhouse gases, accompanied by an increased supply of moisture from the southern hemisphere Indian Ocean. We reconstructed South Asian summer monsoon precipitation and runoff into the Bay of Bengal to assess the extent to which these factors also operated in tImprint of regional oceanography on foraminifera of eastern Pacific Coral Reefs
The marginal marine environments of the eastern tropical Pacific (ETP) serve as an ideal natural laboratory to study how oceanographic and climatic variability influence coral-reef ecosystems. Reefs along the Pacific coast of Panamá span a natural gradient of nutrients, pH, and temperature as a result of stronger seasonal upwelling in the Gulf of Panamá relative to the Gulf of Chiriquí. The ecosysPaCTS 1.0: A crowdsourced reporting standard for paleoclimate data
The progress of science is tied to the standardization of measurements, instruments, and data. This is especially true in the Big Data age, where analyzing large data volumes critically hinges on that data being standardized. Accordingly, the lack of community-sanctioned data standards in paleoclimatology has largely precluded the benefits of Big Data advances in the field. Building upon recent efConsiderations for Globigerinoides ruber (white and pink) paleoceanography: Comprehensive insights from a long‐running sediment trap
We present a detailed analysis of the seasonal distribution, size, morphological variability and geochemistry of co‐occurring pink and white chromotypes of Globigerinoides ruberfrom a high‐resolution (1–2 weeks) and long‐running sediment trap time series in the northern Gulf of Mexico. We find no difference in the seasonal flux of the two chromotypes. Although flux of G. ruber is consistently loweReconstructing precipitation in the tropical South Pacific from dinosterol 2H/1H ratios in lake sediment
The South Pacific Convergence Zone (SPCZ) is the Southern Hemisphere’s largest precipitation feature supplying freshwater to 11 million people. Despite its significance, little is known about the location and intensity of SPCZ precipitation prior to instrumental records, hindering attempts to predict precipitation changes in a warming world. Here we use sedimentary molecular fossils to establish aQuantifying uncertainty in Sr/Ca-based estimates of SST from the coral Orbicella faveolata
The strontium to calcium ratio (Sr/Ca) in aragonitic skeletons of massive corals provides a proxy for sea surface temperature (SST) that can be used to reconstruct paleoclimates across decades, centuries, and, potentially, millennia. Determining the reproducibility of Sr/Ca records among contemporaneous coral colonies from the same region is critical to quantifying uncertainties associated with thEnvironmental controls on the geochemistry of Globorotalia truncatulinoides in the Gulf of Mexico: Implications for paleoceanographic reconstructions
Modern observations of planktic foraminifera from sediment trap studies help to constrain the regional ecology of paleoceanographically valuable species. Results from a weekly-resolved sediment trap time series (2008–2014) in the northern Gulf of Mexico demonstrate that 92% of Globorotalia truncatulinoides flux occurs in winter (January, February, and March), and that encrusted and non-encrusted iA 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 andByWater 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 CenterPronounced centennial-scale Atlantic Ocean climate variability correlated with Western Hemisphere hydroclimate
Surface-ocean circulation in the northern Atlantic Ocean influences Northern Hemisphere climate. Century-scale circulation variability in the Atlantic Ocean, however, is poorly constrained due to insufficiently-resolved paleoceanographic records. Here we present a replicated reconstruction of sea-surface temperature and salinity from a site sensitive to North Atlantic circulation in the Gulf of MeNon-USGS Publications**
Richey J.N., Hollander, D.J., Flower, B.P. and Eglinton, T.I., 2011, Merging late Holocene Molecular Organic and Foraminiferal-Based Geochemical Records of SST in the Gulf of Mexico: Paleoceanography, doi:10.1029/2010PA002000.**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
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