More than a third of the United States population lives in counties directly on the shoreline, making them vulnerable to hazards associated with changing sea level and storm surges associated with hurricanes and severe storms. The geologic record contains many examples of past intervals of warm climate and high sea level. "Geological Investigation of the Neogene" is examining proxy records of ocean conditions (temperature, salinity, upwelling) and the composition and distribution of marine fossil assemblages during these periods to improve understanding of potential rates, magnitudes, and impacts of change.
Paleoclimate Science
Biological proxies such as diatoms, foraminifers, ostracodes, and pollen allow scientists to make inferences about climate conditions in the past.
Florence Bascom Geoscience Center
Learn more about this project and its role in the Florence Bascom Geoscience Center.
Statement of Problem: Our group reconstructs marine environments during past warm intervals using a combination of paleoclimate proxies (e.g. faunal analysis, biomarkers, stratigraphy) from well-dated sediment cores and outcrops. We also compare our paleo reconstructions with those generated by numerical ecosystem and climate models.
Why this Research is Important: We explore the environmental and economic impacts on coastal population centers under different rates and magnitudes of environmental change, using past warm climates as guides. Past warm periods provide a baseline for the impact of changes that can be used to prepare for the effects of the modern warming trend. Large segments of the U.S. population live in coastal communities which rely heavily on local fisheries, agriculture, tourism and national defense installations. This research provides valuable data to inform adaptation strategies related to the ecological health of the marine environment and the threat to infrastructure.
Objective(s): The research focuses on sites within the Atlantic Coastal Plain that preserve evidence from a series of past warm intervals. By documenting patterns and impacts of change during two warm intervals, the Middle Miocene Climatic Optimum (~16 Ma) and the mid-Piacenzian warm period (~3.2 Ma), the project aims to provide examples of past ecologic, environmental, and physical changes to coastal settings. These examples help anticipate the physical and economic impacts of sea surface warming and changing sea level on modern coasts and communities. In addition, through an iterative process, our results can be used to increase confidence in model projections of future change which are of increasing importance to policy makers.
Methods: We reconstruct past conditions using a variety of techniques. Distributions and abundances of different fossil assemblages can be statistically calibrated to generate estimates of temperature, salinity, productivity and seasonality. Often, the presence or morphological characteristics of individual species can be used to indicate specific environmental conditions. In addition, we analyze organic compounds, called biomarkers, to obtain independent estimates of ocean surface temperature and productivity. Stable isotopes of oxygen and carbon, found in the calcium carbonate covering of some microfossils can be used to better understand the salinity and global ice volume at the time the organism was alive. These and other types of analyses all require a sound, high resolution temporal framework constructed using calibrated first and last appearances in the fossil record of key species as well as the record of paleomagnetic reversals and select radiometric dates.
Below are other science projects associated with this project.
Geological Investigations of the Neogene Project
Sea Level and Storm Hazards: Past and Present
Natural Drought and Flood Histories from Lacustrine Archives
Land-Sea Linkages in the Arctic
Pliocene Research, Interpretation and Synoptic Mapping (PRISM4)
Eocene Hyperthermals Project
- Overview
More than a third of the United States population lives in counties directly on the shoreline, making them vulnerable to hazards associated with changing sea level and storm surges associated with hurricanes and severe storms. The geologic record contains many examples of past intervals of warm climate and high sea level. "Geological Investigation of the Neogene" is examining proxy records of ocean conditions (temperature, salinity, upwelling) and the composition and distribution of marine fossil assemblages during these periods to improve understanding of potential rates, magnitudes, and impacts of change.
Paleoclimate Science
Biological proxies such as diatoms, foraminifers, ostracodes, and pollen allow scientists to make inferences about climate conditions in the past.
Florence Bascom Geoscience Center
Learn more about this project and its role in the Florence Bascom Geoscience Center.
Sources/Usage: Public Domain.Photo shows the Calvert Formation (created during Middle Miocene Climatic Optimum (MMCO)) taken at Plum Point on the Chesapeake Bay, in the late afternoon of October 22, 2018. Statement of Problem: Our group reconstructs marine environments during past warm intervals using a combination of paleoclimate proxies (e.g. faunal analysis, biomarkers, stratigraphy) from well-dated sediment cores and outcrops. We also compare our paleo reconstructions with those generated by numerical ecosystem and climate models.
Why this Research is Important: We explore the environmental and economic impacts on coastal population centers under different rates and magnitudes of environmental change, using past warm climates as guides. Past warm periods provide a baseline for the impact of changes that can be used to prepare for the effects of the modern warming trend. Large segments of the U.S. population live in coastal communities which rely heavily on local fisheries, agriculture, tourism and national defense installations. This research provides valuable data to inform adaptation strategies related to the ecological health of the marine environment and the threat to infrastructure.
Objective(s): The research focuses on sites within the Atlantic Coastal Plain that preserve evidence from a series of past warm intervals. By documenting patterns and impacts of change during two warm intervals, the Middle Miocene Climatic Optimum (~16 Ma) and the mid-Piacenzian warm period (~3.2 Ma), the project aims to provide examples of past ecologic, environmental, and physical changes to coastal settings. These examples help anticipate the physical and economic impacts of sea surface warming and changing sea level on modern coasts and communities. In addition, through an iterative process, our results can be used to increase confidence in model projections of future change which are of increasing importance to policy makers.
Sources/Usage: Public Domain.Photo shows the fossil-rich sediments of the mid-Piacenzian warm period (MPWP) that document the rapid warming and sea level rise between about 3.30 and 3.25 million years agao. The hammer is at the conformable boundary between the Rushmere (below) and Morgarts Beach (above) Members of the Yorktown Formation. Methods: We reconstruct past conditions using a variety of techniques. Distributions and abundances of different fossil assemblages can be statistically calibrated to generate estimates of temperature, salinity, productivity and seasonality. Often, the presence or morphological characteristics of individual species can be used to indicate specific environmental conditions. In addition, we analyze organic compounds, called biomarkers, to obtain independent estimates of ocean surface temperature and productivity. Stable isotopes of oxygen and carbon, found in the calcium carbonate covering of some microfossils can be used to better understand the salinity and global ice volume at the time the organism was alive. These and other types of analyses all require a sound, high resolution temporal framework constructed using calibrated first and last appearances in the fossil record of key species as well as the record of paleomagnetic reversals and select radiometric dates.
Sources/Usage: Public Domain.Photo shows USGS geologists obtaining microfossil and biomarker samples from the Calvert Formation at Scientists Cliffs. - Science
Below are other science projects associated with this project.
Geological Investigations of the Neogene Project
Geological Investigations of the Neogene explores past warmer-than-modern climates of the mid-Miocene (about 14-17 million years ago) and Piacenzian (about 3 million years ago) to assess the potential environmental and economic impacts to population centers along the US Atlantic coast under different rates and magnitudes of changes related to warmer temperatures. Specifically, we look at past...Sea Level and Storm Hazards: Past and Present
Sea 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...Natural Drought and Flood Histories from Lacustrine Archives
Previous work performed as part of the USGS Holocene Synthesis project illuminated complex centennial-scale patterns of drought and wetter-than-average conditions across the North American continent interior during the past two millennia, where paleorecord data coverage is sparse. In order to explain the patterns of naturally-occurring drought, floods, and storms for the past, identified by the...Land-Sea Linkages in the Arctic
The 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...Pliocene Research, Interpretation and Synoptic Mapping (PRISM4)
PRISM will help distinguish the USGS as a world leader in paleoclimate research, data generation and delivery for use in addressing the modern world's climate-related needs. We will be recognized for the passion of our researchers and partners in providing quality, innovative paleoclimate interpretation and data analysis to the science (climate change) community and to the public we serve.Eocene Hyperthermals Project
Sudden and extreme global warming events of the past are known as hyperthermals. The most intensely studied of these is the Paleocene-Eocene Thermal Maximum (PETM) that occurred about 56 million years ago. During the PETM, global temperatures rose by ~5°C, ocean acidification was widespread, floral and faunal communities were severely disrupted, and changing oceanic circulation and a disrupted... - Publications
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