Palaeoclimatology and Palaeoceanography from Laminated Sediments

Palaeoclimatology and Palaeoceanography from Laminated Sediments
Author: Alan E. S. Kemp
Publisher: Geological Society of London
Total Pages: 278
Release: 1996
Genre: Nature
ISBN: 9781897799673

The magnitude and causes of decadal to century-scale changes in climate are major issues of global concern. The separation of anthropogenically driven change from natural 'baseline' variability within the atmosphere/ocean system is a prerequisite to identifying human impact on global climate. An understanding of past climate variability is therefore a key to predicting future climate change. The sedimentary record of the oceans, seas and lakes is produced by a series of depositional events that occur on seasonal timescales but can rarely be resolved due to mixing of the sediment by bottomdwelling organisms. Where they are preserved, laminated sediments act like tree rings to record these seasonal-scale processes, such as plankton blooms and floods, and provide a uniquely high-resolution record of environmental change. In addition, annually laminated or 'varved' sediment sequences act as geochronometers against which other timescales can be tested. Laminated sediments may therefore be used to develop records of interannual and decadal-scale variability which serve to test models of climate change. The authors cover a range of topics that include strategies for study and techniques of analysis. A series of case studies, dealing with a variety of lacustrine and marine records, illustrates the wide potential of laminated sediments as palaeoclimatic and palaeoceanographic indicators.

The Holocene and Anthropocene Environmental History of Mexico

The Holocene and Anthropocene Environmental History of Mexico
Author: Nuria Torrescano- Valle
Publisher: Springer Nature
Total Pages: 289
Release: 2019-12-02
Genre: Science
ISBN: 3030317196

This book provides essential information on Mexico’s Holocene and Anthropocene climate and vegetation history. Considering the geography of Mexico – which is home to a variety of climatic and environmental conditions, from desert and tropical to high mountain climates – this book focuses on its postglacial paleoecology and paleoclimatology. Further, it analyses human intervention since the middle Holocene as a major agent of environmental change. Offering a valuable tool for understanding past climate change and its relationship with present climate change, the book is a must-read for botanists, ecologists, palaeontologists and graduate students in related fields.

Climate Since A.D. 1500

Climate Since A.D. 1500
Author: Raymond S. Bradley
Publisher: Psychology Press
Total Pages: 726
Release: 1995
Genre: Climatic changes
ISBN: 9780415120302

First Published in 2004. Routledge is an imprint of Taylor & Francis, an informa company.

A ~3000 Year Multi-Proxy Paleoclimate Record from the Guaymas Basin, Gulf of California

A ~3000 Year Multi-Proxy Paleoclimate Record from the Guaymas Basin, Gulf of California
Author: Zach Stewart
Publisher:
Total Pages: 92
Release: 2017
Genre:
ISBN: 9780355129373

The Guaymas Basin, Gulf of California, is an important site for paleoclimate study due to ideal preservation conditions and high sedimentation rates, which allow for high-resolution analysis of paleoclimate records and investigation of climatic and oceanographic processes that operate over timescales not resolved by modern instrumental records. Furthermore, the Guaymas Basin receives some water advected at depth from the Eastern Tropical North Pacific (ETNP), a region where oceanographic processes are closely coupled to the global climate system. The past climate and oceanography of the Gulf of California and ETNP have been well studied at low resolution over glacial-interglacial timescales: the goal of this study is to elucidate Mid- to Late Holocene oceanographic and climate changes at a higher resolution than previous studies in order to resolve decadal to centennial variance. Three main conclusions can be drawn from the new high-resolution records presented here. First, a careful comparison of radiocarbon dating and layer counting data calls into question the completeness of varved marine sequences in the Guaymas Basinches Second, stable isotopes, elemental composition data, XRF core scan trace metal counts, and smear slide analysis are used to identify a significant change in mean conditions and ecosystem structure at ~2800 yr BP, which is probably driven by southward displacement of the Inter-tropical Convergence Zone (ITCZ). Notably, mean bulk delta15N is ~0.6‰ lower after 2800 yr BP, suggesting decreased denitrification and improved ventilation. Third, important frequencies of variance at centennial and decadal periodicities are identified. Comparison of these new high-resolution proxy records to previous work in other regions suggests that Mid- to Late Holocene changes in the Guaymas Basin may be linked to climate changes across a larger spatial scale.