Use of Proxies in Paleoceanography

Use of Proxies in Paleoceanography PDF Author: Gerhard Fischer
Publisher: Springer Science & Business Media
ISBN: 3642586465
Category : Science
Languages : en
Pages : 768

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Book Description
Paleoceanographic proxies provide infonnation for reconstructions of the past, including climate changes, global and regional oceanography, and the cycles of biochemical components in the ocean. These prox ies are measurable descriptors for desired but unobservable environmental variables such as tempera ture, salinity, primary productivity, nutrient content, or surface-water carbon dioxide concentrations. The proxies are employed in a manner analogous to oceanographic methods. The water masses are first characterized according to their specific physical and chemical properties, and then related to particular assemblages of certain organisms or to particular element or isotope distributions. We have a long-standing series of proven proxies available. Marine microfossil assemblages, for instance, are employed to reconstruct surface-water temperatures. The calcareous shells of planktonic and benthic microorgan isms contain a wealth of paleoceanographic information in their isotopic and elemental compositions. Stable oxygen isotope measurements are used to detennine ice volume, and MglCa ratios are related to water temperatures, to cite a few examples. Organic material may also provide valuable infonnation, e. g. , about past productivity conditions. Studying the stable carbon isotope composition of bulk organic matter or individual marine organic components may provide a measure of past surface-water CO 2 conditions within the bounds of certain assumptions. Within the scope of paleoceanographic investigations, the existing proxies are continuously evolving and improving, while new proxies are being studied and developed. The methodology is improved by analysis of samples from the water column and surface sediments, and through laboratory experiments.

Use of Proxies in Paleoceanography

Use of Proxies in Paleoceanography PDF Author: Gerhard Fischer
Publisher: Springer Science & Business Media
ISBN: 3642586465
Category : Science
Languages : en
Pages : 768

Get Book Here

Book Description
Paleoceanographic proxies provide infonnation for reconstructions of the past, including climate changes, global and regional oceanography, and the cycles of biochemical components in the ocean. These prox ies are measurable descriptors for desired but unobservable environmental variables such as tempera ture, salinity, primary productivity, nutrient content, or surface-water carbon dioxide concentrations. The proxies are employed in a manner analogous to oceanographic methods. The water masses are first characterized according to their specific physical and chemical properties, and then related to particular assemblages of certain organisms or to particular element or isotope distributions. We have a long-standing series of proven proxies available. Marine microfossil assemblages, for instance, are employed to reconstruct surface-water temperatures. The calcareous shells of planktonic and benthic microorgan isms contain a wealth of paleoceanographic information in their isotopic and elemental compositions. Stable oxygen isotope measurements are used to detennine ice volume, and MglCa ratios are related to water temperatures, to cite a few examples. Organic material may also provide valuable infonnation, e. g. , about past productivity conditions. Studying the stable carbon isotope composition of bulk organic matter or individual marine organic components may provide a measure of past surface-water CO 2 conditions within the bounds of certain assumptions. Within the scope of paleoceanographic investigations, the existing proxies are continuously evolving and improving, while new proxies are being studied and developed. The methodology is improved by analysis of samples from the water column and surface sediments, and through laboratory experiments.

The South China Sea

The South China Sea PDF Author: Pinxian Wang
Publisher: Springer Science & Business Media
ISBN: 140209745X
Category : Science
Languages : en
Pages : 506

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Book Description
Pinxian Wang and Qianyu Li The South China Sea (SCS) (Fig. 1. 1) offers a special attraction for Earth scientists world-wide because of its location and its well-preserved hemipelagic sediments. As the largest one of the marginal seas separating Asia from the Paci?c, the largest continent from the largest ocean, the SCS functions as a focal point in land-sea int- actions of the Earth system. Climatically, the SCS is located between the Western Paci?c Warm Pool, the centre of global heating at the sea level, and the Tibetan Plateau, the centre of heating at an altitude of 5,000m. Geomorphologically, the SCS lies to the east of the highest peak on earth, Zhumulangma or Everest in the Himalayas (8,848m elevation) and to the west of the deepest trench in the ocean, Philippine Trench (10,497m water depth) (Wang P. 2004). Biogeographically, the SCS belongs to the so-called “East Indies Triangle” where modern marine and terrestrial biodiversity reaches a global maximum (Briggs 1999). Among the major marginal sea basins from the west Paci?c, the SCS presents some of the best conditions for accumulating complete paleoclimatic records in its hemipelagic deposits. These records are favorable for high-resolution pa- oceanographic studies because of high sedimentation rates and good carbonate preservation. It may not be merely a coincidence that two cores from the southern 14 SCS were among the ?rst several cores in the world ocean used by AMS C dating for high-resolution stratigraphy (Andree et al. 1986; Broecker et al. 1988).

Proxies in Late Cenozoic Paleoceanography

Proxies in Late Cenozoic Paleoceanography PDF Author: C. Hillaire-Marcel
Publisher: Elsevier
ISBN: 0080525040
Category : Science
Languages : en
Pages : 863

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Book Description
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

Quaternary Stratigraphy and Paleoceanography of the Canada Basin, Western Arctic Ocean

Quaternary Stratigraphy and Paleoceanography of the Canada Basin, Western Arctic Ocean PDF Author: Richard Z. Poore
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 40

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Book Description
Climate and paleoceanography of the western Arctic Ocean for the last 1 million years interpreted from our four marine sediment cores.

South Atlantic Paleoceanography

South Atlantic Paleoceanography PDF Author: K. J. Hsu
Publisher: Cambridge University Press
ISBN: 0521266092
Category : Science
Languages : en
Pages : 366

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Book Description
Describes the findings made in the late 1970s and 80s about the history of the South Atlantic Ocean.

Cenozoic History and Paleoceanography of the Central Equatorial Pacific Ocean

Cenozoic History and Paleoceanography of the Central Equatorial Pacific Ocean PDF Author: Tjeerd Hendrik Van Andel
Publisher: Geological Society of America
ISBN: 0813711436
Category : Deep Sea Drilling Project
Languages : en
Pages : 231

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Book Description


Boron Proxies in Paleoceanography and Paleoclimatology

Boron Proxies in Paleoceanography and Paleoclimatology PDF Author: Bärbel Hönisch
Publisher: John Wiley & Sons
ISBN: 1119010632
Category : Science
Languages : en
Pages : 241

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Book Description
Anthropogenic carbon dioxide emissions do not only warm our planet but also acidify our oceans. It is currently unclear to which degree Earth’s climate and marine life will be impacted by these changes but information from Earth history, particularly the geochemical signals of past environmental changes stored in the fossil remains of marine organisms, can help us predict possible future changes. This book aims to be a primer for scientists who seek to apply boron proxies in marine carbonates to estimate past seawater carbonate chemistry and atmospheric pCO2. Boron proxies (δ11B and B/Ca) were introduced nearly three decades ago, with subsequent strides being made in understanding their mechanistic functioning. This text reviews current knowledge about the aqueous systematics, the inorganic and biological controls on boron isotope fractionation and incorporation into marine carbonates, as well as the analytical techniques for measurement of boron proxies. Laboratory and field calibrations of the boron proxies are summarized, and similarities between modern calibrations are explored to suggest estimates for proxy sensitivities in marine calcifiers that are now extinct. Example applications illustrate the potential for reconstructing paleo-atmospheric pCO2 from boron isotopes. Also explored are the sensitivity of paleo-ocean acidity and pCO2 reconstructions to boron isotope proxy systematics that are currently less well understood, including the elemental and boron isotopic composition of seawater through time, seawater alkalinity, temperature and salinity, and their collective impact on the uncertainty of paleo-reconstructions. The B/Ca proxy is based on the same mechanistic principles as the boron isotope proxy, but empirical calibrations suggest seawater pH is not the only controlling factor. B/Ca therefore has the potential to provide a second carbonate parameter that could be paired with δ11B to fully constrain the ocean carbonate system, but the associated uncertainties are large. This text reviews and examines what is currently known about the B/Ca proxy systematics. As more scientists embark on characterizing past ocean acidity and atmospheric pCO2, Boron in Paleoceanography and Paleoclimatology provides a resource to introduce geoscientists to the opportunities and complications of boron proxies, including potential avenues to further refine them.

Encyclopedia of Paleoclimatology and Ancient Environments

Encyclopedia of Paleoclimatology and Ancient Environments PDF Author: Vivien Gornitz
Publisher: Springer Science & Business Media
ISBN: 1402045514
Category : Science
Languages : en
Pages : 1062

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Book Description
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.

Paleoceanography

Paleoceanography PDF Author: Thomas J. M. Schopf
Publisher:
ISBN: 9780674432871
Category :
Languages : en
Pages : 356

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Book Description
Whether in the context of off-shore oil exploration or pure research, the oceans of the geological past have never been of more compelling interest. The recent expansion in oceanographic studies has produced a burgeoning of data on ancient ocean circulation, climate, bathymetry, chemistry, biology, and temperature data that now should be considered in a more general geological and paleontological framework. "Paleoceanography" will serve as an important resource for paleontologists and for a much broader audience of earth and ocean scientists, petroleum geologists, and stratigraphers.

Paleoceanography and Paleoclimatology of the Southern Ocean

Paleoceanography and Paleoclimatology of the Southern Ocean PDF Author: Detlef A. Warnke
Publisher:
ISBN:
Category : Climatic changes
Languages : en
Pages : 180

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Book Description