Earth S Magnetism In The Age Of Sail

Jonkers explores these early efforts both for what they reveal about the history of science and navigation and as a unique record of the actual changes in the Earth's magnetic field. The result, a combination of science and history, will appeal to a broad audience of specialists as well as general readers."--BOOK JACKET.

Initially, this book reviews the general characteristics of the Earth’s magnetic field and the magnetic properties of minerals, and then proceeds to introduce the multifold applications of geomagnetism in earth sciences. The authors analyze the contribution of geomagnetism both in more general geological fields, such as tectonics and geodynamics, and in applied ones, such as prospecting and pollution. Primarily, the book is aimed at undergraduate geology or geophysics students. It is geared to provide them with a general overview of geomagnetism, allowing them to understand what contributions this branch of science can offer in the more special sectors of earth sciences. Graduate students and geology researchers will also benefit from it, as it enables them to gain a clear and concise image of the techniques which can be applied in their areas of specialization.

For the general public, magnetism often seems more the province of new age quacks, movie mad scientists, and grade-school teachers than an area of actual, ongoing scientific inquiry. But as Ronald T. Merrill reveals in Our Magnetic Earth, geomagnetism really is an enduring, vibrant area of science, one that offers answers to some of the biggest questions about our planet’s past—and maybe even its future.

From the Thirteenth century through the Nineteenth, the waterways of the world provided the major means of transportation for exploration, trade, the military, and even criminals. Find out what life was like for those who chose to sail the high seas, as well as for those who didn't choose to be on board, like wives brought to sea by husbands and slaves en route to the auction block. What were their quarters like? What did they eat? How did they pass their long days at sea? These and other questions are answered in animated prose that brings the lives of ordinary people who oftentimes engaged in extraordinary activities, into sharp focus. First-hand accounts from such sources as personal journals and magazine articles are provided to help bring the time period alive. Students will also learn what life was like in the seaport towns and what the sailors did when they visited these towns, as well as the physical parts of the ships and the different roles different members of the crew played. This engaging history helps to separate fact from fiction while exploring the reasons the sea and sea life have held such prominent roles in popular fiction, and will help students understand what life was truly like for these people.

Treatise on Geophysics: Geomagnetism, Volume 5, provides an overview of the most important aspects of geomagnetism. The book begins by tracing the history of the study of geomagnetism. It then reviews global models of the Earth's magnetic field; the main sources of external magnetic field contributions; and the instruments and practices used to observe and measure the full range of features of the geomagnetic field. It discusses the origins of current knowledge of the secular variation of the Earth's magnetic field; crustal magnetism; geomagnetic excursions; the study of geophysical electromagnetic induction; the magnetization process; and the status of recent magnetic field data and their applications. The remaining chapters cover the geometry of the geomagnetic field and its temporal variability as recorded in volcanic and sedimentary rocks over the past few million years; the ocean crust as a recorder of geomagnetic field variations; and the theoretical basis for paleointensity experiments in igneous and sedimentary environments. The final chapter explains the concept of true polar wander (TPW), defined as shifts in the geographic location of Earth's daily rotation axis and/or by fluctuations in the spin rate (length of day anomalies). Self-contained volume starts with an overview of the subject then explores each topic with in depth detail Extensive reference lists and cross references with other volumes to facilitate further research Full-color figures and tables support the text and aid in understanding Content suited for both the expert and non-expert

Focusing on aspects of the functioning of technology, and by looking at instruments and at instrumental performance, this book addresses the epistemological questions arising from examining the technological bases to geographical exploration and knowledge claims. Questions of geography and exploration and technology are addressed in historical and contemporary context and in different geographical locations and intellectual cultures. The collection brings together scholars in the history of geographical exploration, historians of science, historians of technology and, importantly, experts with curatorial responsibilities for, and museological expertise in, major instrument collections. Ranging in their focus from studies of astronomical practice to seismography, meteorological instruments and rockets, from radar to the hand-held barometer, the chapters of this book examine the ways in which instruments and questions of technology - too often overlooked hitherto - offer insight into the connections between geography and exploration.

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