Download or read book Environmental Changes on the North American Mid Atlantic Shelf During the Paleocene Eocene Thermal Maximum written by Edward A. Ballaron and published by . This book was released on 2018 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Environmental Changes on the North American Mid-Atlantic Shelf During the Paleocene Eocene Thermal Maximum Edward A. Ballaron The Paleocene-Eocene Thermal Maximum (PETM), a large hyperthermal during the Cenozoic (& sim;56 Ma) is characterized by a massive injection of depleted carbon into global reservoirs as indicated by a large negative carbon isotope excursion (CIE) of 3 & permil;-5 & permil; in marine and terrestrial sedimentary records. Previously studied open ocean (i.e., pelagic) cores have provided evidence for abrupt sea surface warming (5-10 & deg;C) and bottom water warming (4-5 & deg;C) as well as ocean acidification at the onset of the CIE. However, due to low sedimentation rates and truncation of pelagic sections via dissolution at the CIE, pelagic cores appear condensed or incomplete. Sites on the North American mid-Atlantic margin, provide a unique opportunity to examine both marine and terrestrial responses to a large magnitude climatic perturbation. Rapid and abrupt increases in the flux of siliciclastics including kaolinite to the shelf at the onset of the PETM, indicative of an enhanced hydrologic cycle, result in expanded PETM intervals allowing for higher resolution isotopic sampling. Stable isotopic and trace metal data from New Jersey sections (Millville, Ancora, Bass River and Wilson Lake) have also documented rapid warming, coastal ocean acidification and a freshening event at the onset of the CIE in agreement with evidence for an enhanced hydrologic cycle during the PETM. Maryland sections to the south (South Dover Bridge and Cambridge-Dorchester) studied here, are more proximal to the main drainage system in the Salisbury Embayment and therefore should have experienced environmental changes (salinity) to a greater degree than New Jersey sites. Here we present coupled stable isotopic (carbon and oxygen) and trace metal data (Mg/Ca) to constrain both changes in temperature as well as salinity on the Maryland mid-Atlantic shelf during the PETM. Data presented here shows a temperature increase at SDB and Cam-Dor of & sim;4-5 & deg;C for planktonic foraminifera and & sim;5-9 & deg;C for benthic foraminifera with oxygen derived temperatures being consistently larger than Mg/Ca derived temperatures. This indicates some salinity contribution to delta18O, artificially lowering oxygen derived temperatures. This is further supported by salinity calculations which display a freshening event at the onset of the CIE due to increased runoff. Also observed in this data set is a slight weakening in delta13C and delta18O depth gradients on the shelf. Changes in delta18O gradients can perhaps be attributed to greater warming at depth and a destabilization of the thermal stratification of the water column, similar to observations from New Jersey sites Millivlle and Ancora. The breakdown in vertical delta13C gradients was perhaps due to the vertical migration of mixed layer foraminifera taxa seeking refuge from warming surface waters. Another possible explanation for the change in vertical delta13C gradients is a change in upwelling patterns driven by hyperpycnal flow or changes in wind patterns driving coastal upwelling and bringing depleted delta13C to the surface.
Download or read book Tracking the Paleocene Eocene Thermal Maximum in the North Atlantic written by Kalev Hantsoo and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Paleocene-Eocene Thermal Maximum (PETM), a transient greenhouse interval spurred by a large release of carbon to the ocean-atmosphere ca. 56 Ma, provides a geological point of comparison for anthropogenic carbon emission. However, while geochemical proxies and fossil assemblages offer insights into the continental shelf response to the PETM, existing ocean-atmosphere models of the PETM do not include accurate shelf and slope bathymetry. Model-proxy comparisons are of particular interest along continental margins, which are ecologically and biogeochemically critical environments.Here we present high-resolution simulations of the pre- and syn-PETM North Atlantic basin that include a resolved continental shelf along the eastern margin of North America in the Salisbury Embayment. We use the Regional Ocean Modeling System (ROMS), whose terrain-following coordinate system permits a new level of detail along continental margins while also capturing open ocean processes. Our models boundary conditions are drawn from existing models of the PETM. Under a carbon forcing consistent with a release of ~13000 PgC, the calcite saturation horizon rises to an average depth of 725 m in the North Atlantic. Concurrently, a regime of continental slope downwelling in the western North Atlantic weakens during PETM onset. On the continental shelf, benthic oxygen concentrations decrease by 32.5% with seasonal occurrence of moderate hypoxia, while average benthic calcite saturation declines from 3.2 to 1.9. These declines are primarily driven by oxic respiration spurred by an increase in primary production and a more efficient export flux to the shelf seafloor. Model results do not include river input to the continental shelf, which is hypothesized to have further reduced oxygen and carbonate ion concentrations in the benthic environment.
Download or read book Field Excursions to the Northern Sierra Nevada of California the Mining Districts of the Sierra Nevada and Cretaceous and Paleocene Sediments in Maryland USA written by Harvey Kelsey and published by Geological Society of America. This book was released on 2023-05-24 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Anthropocene as a Geological Time Unit written by Jan Zalasiewicz and published by Cambridge University Press. This book was released on 2019-03-07 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reviews the evidence underpinning the Anthropocene as a geological epoch written by the Anthropocene Working Group investigating it. The book discusses ongoing changes to the Earth system within the context of deep geological time, allowing a comparison between the global transition taking place today with major transitions in Earth history.
Download or read book Polar Environments and Global Change written by Roger G. Barry and published by Cambridge University Press. This book was released on 2018-08-09 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surveys atmospheric, oceanic and cryospheric processes, present and past conditions, and changes in polar environments.
Download or read book Deep time Perspectives on Climate Change written by Mark Williams and published by Geological Society of London. This book was released on 2007 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Understanding Earth s Deep Past written by National Research Council and published by National Academies Press. This book was released on 2011-08-02 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is little dispute within the scientific community that humans are changing Earth's climate on a decadal to century time-scale. By the end of this century, without a reduction in emissions, atmospheric CO2 is projected to increase to levels that Earth has not experienced for more than 30 million years. As greenhouse gas emissions propel Earth toward a warmer climate state, an improved understanding of climate dynamics in warm environments is needed to inform public policy decisions. In Understanding Earth's Deep Past, the National Research Council reports that rocks and sediments that are millions of years old hold clues to how the Earth's future climate would respond in an environment with high levels of atmospheric greenhouse gases. Understanding Earth's Deep Past provides an assessment of both the demonstrated and underdeveloped potential of the deep-time geologic record to inform us about the dynamics of the global climate system. The report describes past climate changes, and discusses potential impacts of high levels of atmospheric greenhouse gases on regional climates, water resources, marine and terrestrial ecosystems, and the cycling of life-sustaining elements. While revealing gaps in scientific knowledge of past climate states, the report highlights a range of high priority research issues with potential for major advances in the scientific understanding of climate processes. This proposed integrated, deep-time climate research program would study how climate responded over Earth's different climate states, examine how climate responds to increased atmospheric carbon dioxide and other greenhouse gases, and clarify the processes that lead to anomalously warm polar and tropical regions and the impact on marine and terrestrial life. In addition to outlining a research agenda, Understanding Earth's Deep Past proposes an implementation strategy that will be an invaluable resource to decision-makers in the field, as well as the research community, advocacy organizations, government agencies, and college professors and students.
Download or read book The Vegetation of Antarctica through Geological Time written by David J. Cantrill and published by Cambridge University Press. This book was released on 2012-11-22 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fossil history of plant life in Antarctica is central to our understanding of the evolution of vegetation through geological time and also plays a key role in reconstructing past configurations of the continents and associated climatic conditions. This book provides the only detailed overview of the development of Antarctic vegetation from the Devonian period to the present day, presenting Earth scientists with valuable insights into the break up of the ancient supercontinent of Gondwana. Details of specific floras and ecosystems are provided within the context of changing geological, geographical and environmental conditions, alongside comparisons with contemporaneous and modern ecosystems. The authors demonstrate how palaeobotany contributes to our understanding of the paleoenvironmental changes in the southern hemisphere during this period of Earth history. The book is a complete and up-to-date reference for researchers and students in Antarctic paleobotany and terrestrial paleoecology.
Download or read book The Environmental Impact of the Paleocene eocene Thermal Maximum on the Coastal Ocean written by Thomas G. Quattlebaum (Jr.) and published by . This book was released on 2004 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Earth History and Palaeogeography written by Trond H. Torsvik and published by Cambridge University Press. This book was released on 2017 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a complete Phanerozoic story of palaeogeography, using new and detailed full-colour maps, to link surface and deep-Earth processes.
Download or read book Fluvial Response to the Paleocene Eocene Thermal Maximum in Western North America written by Brady Z. Foreman and published by . This book was released on 2013 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Paleocene-Eocene boundary ca. 56 million years ago is characterized by an extreme global warming event, known as the Paleocene-Eocene Thermal Maximum (PETM). The event is linked to the massive exogenic release of isotopically-light carbon into Earth's oceans and atmosphere, and is recognizable in the geologic record by an abrupt negative carbon isotope excursion in both organic and inorganic proxy records for duration of approximately 200,000 years. Previous studies indicate the PETM instigated massive changes in ocean and atmospheric circulation, which perturbed both terrestrial and marine environmental conditions and biotic systems. This study exploits the PETM to examine the effects of abrupt climate change on fluvial stratigraphy. The negative carbon isotope excursion associated with the PETM allows the timing and duration of the climate change to be identified independent of lithostratigraphic markers. Local climate shifts are constrained using circulation models, soil geochemistry, and paleobotanical records. Two areas are studied in detail, the Piceance Creek Basin of Colorado and the northern Bighorn Basin of Wyoming. In both areas anomalously thick and laterally persistent fluvial sand-bodies correlate with the PETM interval. In the Piceance Creek Basin the shift in fluvial deposition directly correlates with the onset of the PETM and persists beyond the carbon isotope excursion, whereas in the northern Bighorn Basin the shift appears to lag the isotope excursion by 10-20 thousand years and ends prior to the return to background climatic conditions. In the Piceance Creek Basin the change in sand-body geometry is associated with a shift to deeper paleoflow depths, wider channels, greater preservation of upper flow regime structures, prevalent crevasse splay deposits, and poorer drained floodplain soils. In contrast, within the Bighorn Basin there are no such changes and, apart from greater amalgamation, fluvial deposition appears to be largely unaffected by the PETM. When combined with other PETM terrestrial localities, the records demonstrate the PETM had substantial, but spatially diverse effects on basin-scale grain-size partitioning, discharge regimes, and river-floodplain dynamics. Aspects of the responses in the various basins are reminiscent of those predicted by two-dimensional basin-fill models, however, key differences highlight the role non-linearities, feedback loops, relaxation times, basin geometry, seasonality of precipitation, and vegetation factors play in determining large-scale depositional patterns. Consequently, it is concluded that short-term climatic events such as the PETM hold the potential to strongly alter basin sedimentation patterns, but that the sedimentologic-recorded climatic signal cannot be used to directly reconstruct paleoclimatic conditions. Instead a more appropriate approach is advocated that uses fluvial stratigraphy in concert with geochemical and other proxies to iteratively produce a more robust image of paleolandscape dynamics.
Download or read book Late Paleocene early Eocene Climatic and Biotic Events in the Marine and Terrestrial Records written by Marie-Pierre Aubry and published by Columbia University Press. This book was released on 1998 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a comprehensive collection of the best scholarship available on the transition between the Paleocene and Eocene epochs--when the earth experienced the warmest climatic episode of the Cenozoic era. These 21 contributions detail the major turnover among marine and terrestrial organisms that resulted from sudden global warming.
Download or read book Large Igneous Provinces written by Richard E. Ernst and published by Cambridge University Press. This book was released on 2014-09-25 with total page 667 pages. Available in PDF, EPUB and Kindle. Book excerpt: Large igneous provinces (LIPs) are intraplate magmatic events, involving volumes of mainly mafic magma upwards of 100,000 km3, and often above 1 million km3. They are linked to continental break-up, global environmental catastrophes, regional uplift and a variety of ore deposit types. In this up-to-date, fascinating book, leading expert Richard E. Ernst explores all aspects of LIPs, beginning by introducing their definition and essential characteristics. Topics covered include continental and oceanic LIPs; their origins, structures, and geochemistry; geological and environmental effects; association with silicic, carbonatite and kimberlite magmatism; and analogues of LIPs in the Archean, and on other planets. The book concludes with an assessment of LIPs' influence on natural resources such as mineral deposits, petroleum and aquifers. This is a one-stop resource for researchers and graduate students in a wide range of disciplines, including tectonics, igneous petrology, geochemistry, geophysics, Earth history, and planetary geology, and for mining industry professionals.
Download or read book Large Igneous Provinces written by Richard E. Ernst and published by John Wiley & Sons. This book was released on 2021-02-09 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is Open Access. A digital copy can be downloaded for free from Wiley Online Library. Exploring the links between Large Igneous Provinces and dramatic environmental impact An emerging consensus suggests that Large Igneous Provinces (LIPs) and Silicic LIPs (SLIPs) are a significant driver of dramatic global environmental and biological changes, including mass extinctions. Environmental changes caused by LIPs and SLIPs include rapid global warming, global cooling ('Snowball Earth'), oceanic anoxia events, mercury poisoning, atmospheric and oceanic acidification, and sea level changes. Continued research to characterize the effects of these extremely large and typically short duration igneous events on atmospheric and oceanic chemistry through Earth history can provide lessons for understanding and mitigating modern climate change. Large Igneous Provinces: A Driver of Global Environmental and Biotic Changes describes the interactions between the effects of LIPs and other drivers of climatic change, the limits of the LIP effect, and the atmospheric and oceanic consequences of LIPs in significant environmental events. Volume highlights include: Temporal record of large igneous provinces (LIPs) Environmental impacts of LIP emplacement Precambrian, Proterozoic, and Phanerozoic case histories Links between geochemical proxies and the LIP record Alternative causes for environmental change Key parameters related to LIPs and SLIPs for use in environmental change modelling Role of LIPs in Permo-Triassic, Triassic-Jurassic, and other mass extinction events The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals.
Download or read book Nitrogen in the Marine Environment written by Edward J. Carpenter and published by Elsevier. This book was released on 2013-10-22 with total page 919 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen in the Marine Environment provides information pertinent to the many aspects of the nitrogen cycle. This book presents the advances in ocean productivity research, with emphasis on the role of microbes in nitrogen transformations with excursions to higher trophic levels. Organized into 24 chapters, this book begins with an overview of the abundance and distribution of the various forms of nitrogen in a number of estuaries. This text then provides a comparison of the nitrogen cycling of various ecosystems within the marine environment. Other chapters consider chemical distributions and methodology as an aid to those entering the field. This book discusses as well the enzymology of the initial steps of inorganic nitrogen assimilation. The final chapter deals with the philosophy and application of modeling as an investigative method in basic research on nitrogen dynamics in coastal and open-ocean marine environments. This book is a valuable resource for plant biochemists, microbiologists, aquatic ecologists, and bacteriologists.
Download or read book Causes and Consequences of Globally Warm Climates in the Early Paleogene written by Scott L. Wing and published by Geological Society of America. This book was released on 2003-01-01 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A revised correlation of Tertiary rocks in the British Isles and adjacent areas of NW Europe written by C. King and published by Geological Society of London. This book was released on 2016-01-05 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Special Report comprehensively describes the stratigraphy and correlation of the Tertiary (Paleogene–Neogene) rocks of NW Europe and the adjacent Atlantic Ocean and is the summation of fifty years of research on Tertiary sediments by Chris King. His book is essential reading for all geologists who deal with Tertiary rocks across NW Europe, including those in the petroleum industry and geotechnical services as well as academic stratigraphers and palaeontologists. Introductory sections on chronostratigraphy, biostratigraphy and other methods of dating and correlation are followed by a regional summary of Tertiary sedimentary basins and their framework and an introduction to Tertiary igneous rocks. The third and largest segment comprises the regional stratigraphic summaries. Regions covered are the North Sea Basin, onshore areas of southern England and the eastern English Channel area, the North Atlantic margins (including non-marine basins in the Irish Sea and elsewhere) and the Paleogene igneous rocks of Scotland.
