Download or read book Orbital and Millennial Scale Ice Sheet and Ocean Variability in the North Atlantic During the Pliocene and Pleistocene Climate Transitions written by Helga Flesche Kleiven and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Orbital and Millenial Scale Ice Sheet and Ocean Variability in the North Atlantic During the Pliocene and Pleistocene Climate Transitions written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Early Middle Pleistocene Transitions written by Geological Society of London and published by Geological Society of London. This book was released on 2005 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Early-Middle Pleistocene transition (around 1.2 to 0.5 Ma) marks a profound shift in Earth's climate state. Low-amplitude 41 ka climate cycles, dominating the earlier part of the Pleistocene, gave way progressively to a 100 ka rhythm of increased amplitude that characterizes our present glacial-interglacial world. This volume assesses the biotic and physical response to this transition both on land and in the oceans: indeed it examines the very nature of Quaternary climate change. Milankovitch theory, palaeoceanography using isotopes and microfossils, marine organic geochemistry, tephrochronology, the record of loess and soil deposition, terrestrial vegetational change, and the migration and evolution of hominins as well as other large and small mammals, are all considered. These themes combine to explore the very origins of our present biota.
Download or read book Orbital to Millennial scale Variability in Gulf of Mexico Sea Surface Temperature and Salinity During the Late Pleistocene written by Jessica L. Whitaker and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The initial rise in GOM SST at 132.1 ka of 2.9 °C is followed by a cold reversal of 1.5 °C at 130.4 ka for 2 ky and final increase to full interglacial warmth. The reversal in GOM SST is consonant with a pause in sea level rise and reduced NADW, suggesting a reduction in THC may have caused a global two-step deglaciation.
Download or read book Proceedings of the Ocean Drilling Program written by Ocean Drilling Program and published by . This book was released on 1995 with total page 1196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paleoclimates written by Thomas M. Cronin and published by Columbia University Press. This book was released on 2010 with total page 465 pages. Available in PDF, EPUB and Kindle. Book excerpt: "When combined with computer model simulations, paleoclimatic reconstructions are used to test hypotheses about the causes of climatic change, such as greenhouse gases, solar variability, earth's orbital variations, and hydrological, oceanic, and tectonic processes, This book is a comprehensive, state-of-the art synthesis of paleoclimate research covering all geological timescales, emphasizing topics that shed light on modern trends in the earth's climate." --Book Jacket.
Download or read book Proceedings of the Ocean Drilling Program written by Ocean Drilling Program and published by . This book was released on 1995-07-07 with total page 1218 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Encyclopedia of Paleoclimatology and Ancient Environments written by Vivien Gornitz and published by Springer Science & Business Media. This book was released on 2008-10-31 with total page 1062 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of Springer’s Major Reference Works, this book gives the reader a truly global perspective. It is the first major reference work in its field. Paleoclimate topics covered in the encyclopedia give the reader the capability to place the observations of recent global warming in the context of longer-term natural climate fluctuations. Significant elements of the encyclopedia include recent developments in paleoclimate modeling, paleo-ocean circulation, as well as the influence of geological processes and biological feedbacks on global climate change. The encyclopedia gives the reader an entry point into the literature on these and many other groundbreaking topics.
Download or read book A High resolution Record of Climate Instability Spanning 1 0 Million Years Across the Mid Pleistocene Transition written by Daniel R. Weirauch and published by ProQuest. This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: I use oxygen isotopes of planktonic foraminiferal species Globigerinoides ruber from Ocean Drilling Program (ODP) Site 1058 in the subtropical northwestern Atlantic to construct a high-resolution climate record spanning the mid-Pleistocene transition from ~411 Ka to 1.35 Ma. The main purpose of this study is to analyze climatic instability on both orbital and suborbital scales during a long transitional interval from dominant 41-kyr glacial cycles to more developed 100-kyr cycles. I provide age control based on two different models using Northern Hemisphere summer insolation and the ODP Site 677 G. ruber [delta] 18 O record of Shackleton et al. (1991) as tuning targets. The results indicate that independent of age control, the appearance and recurrence of significant millennial-scale variability with periods between 3 kyr and 8 kyr begins around 800 Ka. At this time, high-amplitude 4 to 8 kyr cycles become more frequent, with the highest amplitude millennial-scale variability occurring at ~420 kyr during the most extreme glacial interval (Marine Isotope Stage, MIS 12) within the length of the record. I believe that the appearance of millennial-scale variability in association with the evolution of 100-kyr glacial cycles and the occurrence of high-amplitude millennial-scale variability during the most extreme glacial interval is consistent with the strong influence of a tall, thick northern ice sheet on atmospheric circulation patterns. In addition, consideration of the long-term trends in the [delta] 18 O record from ODP Site 1058 indicates a dramatic cooling event just after 900 Ka (MIS 22). This excursion is recorded in other regions in the Atlantic and Pacific Oceans supporting a global-scale, large magnitude cooling event during one of the major Pleistocene climate transitions.
Download or read book Earth s Climate Evolution written by C. P. Summerhayes and published by John Wiley & Sons. This book was released on 2015-07-13 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: To understand climate change today, we first need to know how Earth’s climate changed over the past 450 million years. Finding answers depends upon contributions from a wide range of sciences, not just the rock record uncovered by geologists. In Earth’s Climate Evolution, Colin Summerhayes analyzes reports and records of past climate change dating back to the late 18th century to uncover key patterns in the climate system. The book will transform debate and set the agenda for the next generation of thought about future climate change. The book takes a unique approach to the subject providing a description of the greenhouse and icehouse worlds of the past 450 million years since land plants emerged, ignoring major earlier glaciations like that of Snowball Earth, which occurred around 600 million years ago in a world free of land plants. It describes the evolution of thinking in palaeoclimatology and introduces the main players in the field and how their ideas were received and, in many cases, subsequently modified. It records the arguments and discussions about the merits of different ideas along the way. It also includes several notes made from the author’s own personal involvement in palaeoclimatological and palaeoceanographic studies, and from his experience of working alongside several of the major players in these fields in recent years. This book will be an invaluable reference for both undergraduate and postgraduate students taking courses in related fields and will also be of interest to historians of science and/or geology, climatology and oceanography. It should also be of interest to the wider scientific and engineering community, high school science students, policy makers, and environmental NGOs. Reviews: "Outstanding in its presentation of the facts and a good read in the way that it intersperses the climate story with the author's own experiences. [This book] puts the climate story into a compelling geological history." -Dr. James Baker "The book is written in very clear and concise prose, [and takes] original, enlightening, and engaging approach to talking about 'ideas' from the perspective of the scientists who promoted them." -Professor Christopher R. Scotese "A thrilling ride through continental drift and its consequences." - Professor Gerald R. North "Written in a style and language which can be easily understood by laymen as well as scientists." - Professor Dr Jörn Thiede "What makes this book particularly distinctive is how well it builds in the narrative of change in ideas over time." - Holocene book reviews, May 2016 "This is a fascinating book and the author’s biographical approach gives it great human appeal." - E Adlard
Download or read book Antarctic Climate Evolution written by Fabio Florindo and published by Elsevier. This book was released on 2008-10-10 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt: Antarctic Climate Evolution is the first book dedicated to furthering knowledge on the evolution of the world's largest ice sheet over its ~34 million year history. This volume provides the latest information on subjects ranging from terrestrial and marine geology to sedimentology and glacier geophysics. - An overview of Antarctic climate change, analyzing historical, present-day and future developments - Contributions from leading experts and scholars from around the world - Informs and updates climate change scientists and experts in related areas of study
Download or read book Climate Change written by Jason Smerdon and published by Columbia University Press. This book was released on 2018-10-30 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: This second edition of Climate Change is an accessible and comprehensive guide to the science behind global warming. Exquisitely illustrated, the text is geared toward students at a variety of levels. Edmond A. Mathez and Jason E. Smerdon provide a broad, informative introduction to the science that underlies our understanding of the climate system and the effects of human activity on the warming of our planet. Mathez and Smerdon describe the roles that the atmosphere and ocean play in our climate, introduce the concept of radiation balance, and explain climate changes that occurred in the past. They also detail the human activities that influence the climate, such as greenhouse gas and aerosol emissions and deforestation, as well as the effects of natural phenomena. Climate Change concludes with a look toward the future, discussing climate model projections, exploring the economic and technological realities of energy production, and presenting a view of the global warming challenge through the lens of risk. Each chapter features profiles of scientists who advanced our understanding of the material discussed. This new edition expands on the first edition’s presentation of scientific concepts, making it ideal for classroom use for a wide swath of undergraduate and masters students with both science and nonscience backgrounds.
Download or read book Ocean Temperature Variability During the Late Pleistocene written by Jeremy Scott Hoffman and published by . This book was released on 2016 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation explores one overarching question relevant to the paleoclimate of the latest Pleistocene glacial cycle (approximately the last 130,000 years): “How did spatial and temporal evolution of ocean temperature, both at the surface and interior, relate to other parts of the climate system in the late Pleistocene?” Results from three studies are presented that seek to address longstanding questions in paleoceanography and paleoclimatology for the late Pleistocene using a combination of novel and accepted statistical and geochemical analysis techniques and leveraging comparisons with available global climate model data. The last interglaciation (LIG; ~129-116 ka) was the most recent period in Earth’s history with higher-than-present global sea level (≥6-9 m) under similar-to-preindustrial concentrations of atmospheric CO2. This suggests that additional feedbacks related to albedo, insolation, and ocean overturning circulation may have resulted in the apparent warming required to cause the higher sea level. Our understanding of how much warmer the LIG was relative to the present interglaciation remains uncertain, however, with current estimates suggesting that sea-surface temperatures (SSTs) were 0-2°C warmer than late-20th century average global temperatures. We present a global compilation of proxy-based annual SST spanning the LIG. Using Monte Carlo and Bayesian techniques to propagate uncertainties in age-model and proxy-based SST reconstructions, our results quantify the spatial timing, amplitude, and uncertainty in global and regional SST change during the LIG. Our conclusions suggest that the LIG surface ocean was indistinguishable from the average surface ocean temperatures observed for the last two decades (1995-2014). This may ultimately imply that the Earth is currently committed to ≥6-9m of equilibrium sea-level rise. Although the LIG is not an analogue for present and future climate change due to the large differences in seasonal orbital insolation and absence of anthropogenic greenhouse gas radiative forcing, it provides an opportunity to test the ability of global climate models to simulate the mechanisms and climate feedbacks responsible for the warmer climate and higher global mean sea level during the LIG. However, when forced only by LIG greenhouse gas concentrations and insolation changes, climate models suggest that the annual mean temperature response was not significantly different from preindustrial control simulations. We present the first multi-model and multiscenario ensemble of transient and equilibrium global climate modeling results spanning the LIG. We show, using a novel model-data comparison framework, that these scenario-specific model results exhibit regionally independent agreement with ocean basin-specific proxy-based SST stacks. This result ultimately implies structural uncertainties and/or misrepresentations of climate feedbacks in the existing suite of climate model simulations, or underestimations of additional proxy-based SST uncertainties. Our conclusions suggest a new target LIG time period for future model-data comparisons and highlight the need for higher resolution transient climate modeling of the LIG and its dependence on meltwater input to the high latitude oceans during the preceding deglaciation. Few discoveries have stimulated the paleoclimate community more so than Heinrich events. Nevertheless, the cause of Heinrich events, characterized by a large flux of icebergs sourced from the Hudson Strait Ice Stream into the North Atlantic, remains debated. Commonly attributed to internal ice-sheet instability, the occurrence of Heinrich events during the coldest intervals of the last glacial cycle instead suggests an external climate control. We expand on recent studies that have shown that incursions of warm subsurface waters into the intermediate depth North Atlantic Ocean destabilized an ice shelf fronting the Hudson Strait Ice Stream, causing a Heinrich event. We present new surface- and bottom-water stable isotope, trace metal, and sedimentary records from two cores taken along the Labrador margin that further support subsurface warming as a trigger of Hudson Strait Heinrich events. We further relate these changes to other sediment core records from the North Atlantic and transient deglacial climate modeling results to show that subsurface warming was ubiquitous across the intermediate North Atlantic during the early part of the last deglaciation and was most likely caused by a preceding reduction in the Atlantic Meridional Overturning Circulation.
Download or read book Environmental Variations in the North Atlantic in Response to Quaternary Glaciations written by AUTHOR UNKNOWN. and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "In this book, the sea surface and deep water conditions in the mid-latitude North Atlantic during the Quaternary are reconstructed based on the analysis of both planktonic and benthic microfaunal assemblages from the SW Iberian margin. The key location of the study site, and the comparison with other sites in the North Atlantic, allow for the drawing of basin-wide conclusions. Millennial-scale variability in Sea Surface Temperature (SST) occurred during interglacial and glacial periods, but with a wider amplitude (> 5 oC) at glacial onsets and terminations. Pronounced stadial events were recorded at all deglaciations during the Quaternary. This prominent cooling of surface waters is the result of major reorganizations of North Atlantic circulation in response to freshwater release to the North Atlantic when ice sheets collapse at the onset of deglaciations. The slowdown of North Atlantic deep-water formation associated to such freshening events reduced the northward flow of the warm subtropical North Atlantic Drift and enhanced the southward advection of cold subpolar waters. Following each episode of severe cooling at the onset of deglaciations, surface water experienced abrupt warming that initiated the climatic optimum during the early phase of interglacials. Abrupt warming was recorded by a sudden increase of the subtropical assemblage that indicates enhanced northward transport of heat through the North Atlantic Drift. At the onset of glaciations, SST in middle latitudes remained relatively warm while the surface waters of the North Atlantic experienced cooling, producing a wide latitudinal SST gradient. The Southwest Iberian margin is highly sensitive to changes in the distribution of North Atlantic currents and both surface and deep water masses, as well as to changes in the position of the Arctic and subtropical fronts. Integrative research including deep and surface analysis has been conducted in this area to evaluate the incidence that surface changes had on deep-sea environments. Results reveal the predominance of well-oxygenated bottom and pore-waters, as well as an abundance of food in the sediment for benthic communities. Nevertheless, significant changes in surface productivity and food availability in the sea floor are recorded between glacials and interglacials. Interglacial surface productivity is much lower than during glacial activity, which, combined with the presence of the highly oxygenated North Atlantic deep water, results in reduced organic matter availability for benthic communities. On the other hand, during glacials when the bottom-water mass is the oxygen-depleted Antarctic bottom water and the organic matter supply from the surface is higher, the combination results in better environmental conditions for benthic communities."--
Download or read book Proxies in Late Cenozoic Paleoceanography written by C. Hillaire-Marcel and published by Elsevier. This book was released on 2007-05-25 with total page 863 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present volume is the first in a series of two books dedicated to the paleoceanography of the Late Cenozoic ocean. The need for an updated synthesis on paleoceanographic science is urgent, owing to the huge and very diversified progress made in this domain during the last decade. In addition, no comprehensive monography still exists in this domain. This is quite incomprehensible in view of the contribution of paleoceanographic research to our present understanding of the dynamics of the climate-ocean system. The focus on the Late Cenozoic ocean responds to two constraints. Firstly, most quantitative methods, notably those based on micropaleontological approaches, cannot be used back in time beyond a few million years at most. Secondly, the last few million years, with their strong climate oscillations, show specific high frequency changes of the ocean with a relatively reduced influcence of tectonics. The first volume addresses quantitative methodologies to reconstruct the dynamics of the ocean andthe second, major aspects of the ocean system (thermohaline circulation, carbon cycle, productivity, sea level etc.) and will also present regional synthesis about the paleoceanography of major the oceanic basins. In both cases, the focus is the "open ocean leaving aside nearshore processes that depend too much onlocal conditions. In this first volume, we have gathered up-to-date methodologies for the measurement and quantitative interpretation of tracers and proxies in deep sea sediments that allow reconstruction of a few key past-properties of the ocean( temperature, salinity, sea-ice cover, seasonal gradients, pH, ventilation, oceanic currents, thermohaline circulation, and paleoproductivity). Chapters encompass physical methods (conventional grain-size studies, tomodensitometry, magnetic and mineralogical properties), most current biological proxies (planktic and benthic foraminifers, deep sea corals, diatoms, coccoliths, dinocysts and biomarkers) and key geochemical tracers (trace elements, stable isotopes, radiogenic isotopes, and U-series). Contributors to the book and members of the review panel are among the best scientists in their specialty. They represent major European and North American laboratories and thus provide a priori guarantees to the quality and updat of the entire book. Scientists and graduate students in paleoclimatology, paleoceanography, climate modeling, and undergraduate and graduate students in marine geology represent the target audience. This volume should be of interest for scientists involved in several international programs, such as those linked to the IPCC (IODP – Integrated Ocean Drilling Program; PAGES – Past Global Changes; IMAGES – Marine Global Changes; PMIP: Paleoclimate Intercomparison Project; several IGCP projects etc.), That is, all programs that require access to time series illustrating changes in the climate-ocean system. - Presents updated techniques and methods in paleoceanography - Reviews the state-of-the-art interpretation of proxies used for quantitative reconstruction of the climate-ocean system - Acts as a supplement for undergraduate and graduate courses in paleoceanography and marine geology
Download or read book Diatoms of Lakes Prespa and Ohrid written by Zlatko Levkov and published by Gantner Publishing. This book was released on 2007 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lakes Preska and Ohrid belong to the old tectonic oligomicticdeep isolated lakes . A total of 450 taxa are presented, 78(17.3%) being described as new taxa (1 genus, 73 speciesand 4 varieties) 9 taxa have new combinations or status.Presence of relict species has been confirmed. Naviculaturris HUSTEDT is reported for the first time outside theKopecz Tertiary deposits in a recent lake.
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.
