Download or read book Late Pleistocene Changes in Northern Component Water written by Aurora Cassandra Elmore and published by . This book was released on 2009 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation reconstructs late Pleistocene oceanic circulation variability within the North Atlantic, a critical region of deep-water formation, using proxies that reconstruct surface and deepwater changes. Unlike other studies that examine North Atlantic circulation as a whole, my study focuses on changes in Iceland Scotland Overflow Water (ISOW), one of the largest contributors to Northern Component Water (NCW). Each NCW component reflects the regional climate within its formation region; thus, different climates may produce different deepwater states by changing the relative contribution from each component. Southern Gardar Drift is bathed by ISOW, thus the accumulating sediments are ideal for examining ISOW. A high-resolution record of the Younger Dryas cold event provides an analog for abrupt climate events. The benthic foraminiferal [delta]13C record from core 11JPC (2707m) on Gardar Drift reveals NCW shoaled during the early and late Younger Dryas. These reductions are coincident with increased meltwater from Northern Hemisphere ice sheets, linking surface freshening to NCW production changes on short-timescales. On longer time-scales, benthic foraminiferal [delta]13C records from Gardar Drift show ISOW density was paced by northern high-latitude summer insolation, particularly within the precessional band. Uniform benthic foraminiferal [delta]13C values on Gardar Drift indicate that the mixing zone between NCW and Southern Component Water (SCW) was positioned to the south of Gardar Drift during interglacial periods. Conversely a large north-south gradient in benthic foraminiferal [delta]13C values during glacial periods indicates that ISOW shoaled, allowing SCW to bathe southern Gardar Drift. High-frequency ISOW variability caused by surface freshening during intermediate climate states is superimposed on the orbitally paced variations. A study of the trace metal compositions in Krithe carapaces found in core top samples demonstrates that calcification temperature is the dominant control on magnesium incorporation. Carbonate ion concentration is a secondary control on magnesium to calcium (Mg/Ca) ratios at low temperatures (

Download or read book The South Atlantic in the Late Quaternary written by Gerold Wefer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 742 pages. Available in PDF, EPUB and Kindle. Book excerpt: The South Atlantic plays a critical role in the couplingofoceanic processes between the Antarctic and the lower latitudes. The Antarctic Ocean, along with the adjacent southern seas, is of substantial importance for global climate and for the distributionofwater masses because itprovides large regions ofthe world ocean with intermediate and bottom waters. In contrast to the North Atlantic, the Southern Ocean acts more as an "information distributor", as opposed to an amplifier. Just as the North Atlantic is influencedby the South Atlantic through the contributionofwarm surface water,the incomingsupply ofNADW - in the area of the Southern Ocean as Circumantarctic Deep Water - influences the oceanography ofthe Antarctic. The competing influences from the northern and southern oceans on the current and mass budget systems can be best studied in the South Atlantic. Not only do changes in the current systems in the eastern Atlantic high-production regions affect the energy budget, they also influence the nutrient inventories, and therefore impact the entire productivity ofthe ocean. In addition, the broad region of the polar front is a critical area with respect to productivity-related circulation since it is the source of Antarctic Intermediate Water. Although theAntarctic Intermediate Watertoday liesdeeper than the water that rises in the upwelling regions, it is the long-term source ofnutrients that are ultimately responsible for the supply oforganic matter to the sea floor and to sediments.

Download or read book Tracking Environmental Change Using Lake Sediments written by John P. Smol and published by Springer Science & Business Media. This book was released on 2006-04-11 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: This third volume in the Developments in Paleoenvironmental Research series deals with the major terrestrial, algal, and siliceous indicators used in paleolimnology. Other volumes deal with the acquisition and archiving of lake sediment cores, chronological techniques, and large-scale basin analysis methods (Volume 1), physical and geochemical parameters and methods (Volume 2), zoological techniques (Volume 4), and statistical and data handling methods (Volume 5). These monographs will provide sufficient detail and breadth to be useful handbooks for both seasoned practitioners as well as newcomers to the area of paleolimnology. Although the chapters in these volumes target mainly lacustrine settings, many of the techniques described can also be readily applied to fluvial, glacial, marine, estuarine, and peatland environments.

Download or read book Stratigraphic Evidence of Water level Changes in Small Lakes in the Souther Great Lakes Region During the Late Quaternary written by Tessa Ray-Cozzens and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Paleoclimate records across mid-latitude North America indicate a continuously changing hydroclimate during the Holocene. However, spatial differences in the hydroclimate history between regions like the mid-continent coastal and northeast United States raises questions about the timing and directions of change in the Southern Great Lakes region. Here, I present ground penetrating radar (GPR) and sediment core analyses from two small lakes in southern Michigan and central Pennsylvania to constrain the extent of late-Pleistocene and Holocene droughts. Sedimentological analyses at Lake Lavine, Michigan, indicate lower than modern water levels before the late-Holocene, particularly during the late-Pleistocene and five particularly dry portions of the Holocene from 9.9–9.8, 8.1–6.6, 6.1–5.4, 5.1–4.9, and 4.7–4.6 ka. Similar analyses at Sunfish Pond, Pennsylvania, also indicate that the lake was higher during the late-Holocene than earlier periods with a severe dry phase from 5.5–4.3 ka nearly desiccating the mountain-top lake as part of an event that extended from Wisconsin to Massachusetts. Two earlier high-water phases at Sunfish Pond possibly coincided with Heinrich Stadial 1 (16.1 ka) and the Younger Dryas (12.4–11.6 ka). The evidence of hydroclimate change highlights the potential influences of the Laurentide Ice Sheet and North Atlantic variability on moisture availability across large portions of eastern North America that produced both spatially-extensive, long-term trends and regionally-varying multi-century fluctuations.

Download or read book Haida Gwaii written by Daryl W. Fedje and published by UBC Press. This book was released on 2011-11-01 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most isolated archipelago on the west coast of the Americas, inhabited for at least 10,500 years, Haida Gwaii has fascinated scientists, social scientists, historians, and inquisitive travellers for decades. This book brings together the results of extensive and varied field research by both federal agencies and independent researchers, and carefully integrates them with earlier archaeological, ethnohistorical, and paleoenvironmental work in the region. It imparts significant new information about the natural history of Haida Gwaii, also known as the Queen Charlotte Islands, and the adjacent areas of Hecate Strait. Chapters analyze new data on ice retreat, shoreline and sea level change, faunal communities, and culture history, providing a more comprehensive picture of the history of the islands from the late glacial through the prehistoric period, to the time of European contact, known to the Haida as the "time of the Iron People."

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 Quaternary Sea Level Changes written by Colin V. Murray-Wallace and published by Cambridge University Press. This book was released on 2014-01-30 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important overview of Quaternary climates including detailed Pleistocene and Holocene sea-level changes, for researchers and graduate and advanced undergraduate students.

Download or read book Late Pleistocene Marine Paleoecology and Zoogeography in Central California written by Warren O. Addicott and published by . This book was released on 1966 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Invertebrate assemblages analogous to the Aleutain molluscan province indicate a former cool-temperate marine climate.

Download or read book North Atlantic Intermediate and Deep Water Nutrient Proxies and Climate written by Katherine McIntyre and published by . This book was released on 1998 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Late Pleistocene Changes in Pacific Intermediate Water Ventilation written by Edwin Wheeler Emmer and published by . This book was released on 1998 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book North America and Adjacent Oceans During the Last Deglaciation written by William F. Ruddiman and published by . This book was released on 1987 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Submerged Landscapes of the European Continental Shelf written by Nicholas C. Flemming and published by John Wiley & Sons. This book was released on 2017-08-07 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quaternary Paleoenvironments examines the drowned landscapes exposed as extensive and attractive territory for prehistoric human settlement during the Ice Ages of the Pleistocene, when sea levels dropped to 120m-135m below their current levels. This volume provides an overview of the geological, geomorphological, climatic and sea-level history of the European continental shelf as a whole, as well as a series of detailed regional reviews for each of the major sea basins. The nature and variable attractions of the landscapes and resources available for human exploitation are examined, as are the conditions under which archaeological sites and landscape features are likely to have been preserved, destroyed or buried by sediment during sea-level rise. The authors also discuss the extent to which we can predict where to look for drowned landscapes with the greatest chance of success, with frequent reference to examples of preserved prehistoric sites in different submerged environments. Quaternary Paleoenvironments will be of interest to archaeologists, geologists, marine scientists, palaeoanthropologists, cultural heritage managers, geographers, and all those with an interest in the drowned landscapes of the continental shelf.

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 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 The Oxford Handbook of Wetland Archaeology written by Francesco Menotti and published by Oxford University Press, USA. This book was released on 2013 with total page 970 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Handbook sets out the key issues and debates in the theory and practice of wetland archaeology which has played a crucial role in studies of our past. Due to the high quantity of preserved organic materials found in humid environments, the study of wetlands has allowed archaeologists to reconstruct people's everyday lives in great detail.

Download or read book Water Environment and Society in Times of Climatic Change written by Arie S. Issar and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the greenhouse effect emerged as a predictable threat, necessitating the evalu ation of its future impact on the environment in the various parts of the globe, interest in the climate changes during the Holocene has gained momentum. The background can be summarized by the sentence: The past is a key to the future. As a matter of fact, this sentence is in the opposite direction, on the dimension of time, to the principle adopted by the founders of the science of geology. They proposed that geological processes in the present should be used as a key for understanding the past. Another reason for the interest in the history of the climate of the Holocene can be described as the renaissance of a modified deterministic approach to the inter relation between physical and human geography. This relates in the first place to the fact that various investigations, especially as carried out by Hubert Lamb, showed that the sequence of climate changes previously suggested by Blytt and Sernander for Europe and adopted by most Holocene climatologists was far too general, and that there were more climate changes during recent history than previously taken account of. In the second place it was found out that these changes had had an impact on the history of human communities. Thus, one can conclude that once the taboo on geographical determinism (i. e.

Download or read book Second Assessment of Climate Change for the Baltic Sea Basin written by The BACC II Author Team and published by Springer. This book was released on 2015-04-03 with total page 515 pages. Available in PDF, EPUB and Kindle. Book excerpt: ​This book is an update of the first BACC assessment, published in 2008. It offers new and updated scientific findings in regional climate research for the Baltic Sea basin. These include climate changes since the last glaciation (approx. 12,000 years ago), changes in the recent past (the last 200 years), climate projections up until 2100 using state-of-the-art regional climate models and an assessment of climate-change impacts on terrestrial, freshwater and marine ecosystems. There are dedicated new chapters on sea-level rise, coastal erosion and impacts on urban areas. A new set of chapters deals with possible causes of regional climate change along with the global effects of increased greenhouse gas concentrations, namely atmospheric aerosols and land-cover change. The evidence collected and presented in this book shows that the regional climate has already started to change and this is expected to continue. Projections of potential future climates show that the region will probably become considerably warmer and wetter in some parts, but dryer in others. Terrestrial and aquatic ecosystems have already shown adjustments to increased temperatures and are expected to undergo further changes in the near future. The BACC II Author Team consists of 141 scientists from 12 countries, covering various disciplines related to climate research and related impacts. BACC II is a project of the Baltic Earth research network and contributes to the World Climate Research Programme.