Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 59. As part of the Nineteenth General Assembly of The International Union of Geodesy and Geophysics Symposium (IUGG) in Vancouver, Canada, Union Symposium U4, "Variations in Earth Rotation" was held August 18-19 1987. The Convenor was Dennis D. McCarthy, U.S. Naval Observatory with P. Paquet, Observatoire Royal de Belgique and M. G. Rochester, St. Johns University serving as co-convernors. In a session on internal structure of the Earth papers dealt with the geophysical effects on Earth rotation parameters. Mantle anelasticity increases the free core nutation (FCN) period by a few days. The period of the FCN and the amplitudes of the main nutation components are sensitive to the ellipticity of the core?]mantle boundary (CMB), and a non-hydrostatic increase of 400m in the flattening of the CMB is a possible explanation of the discrepancies from theory. An alternative suggestion rests on the subseismic description of the nutation spectrum of the stratified liquid core. Evidently new models will have to take into account contributions from the oceans, mantle anelasticity, non-hydrostatic pre-stress, CMB topography and internal core structure.

An analysis of the irregular rotation of the Earth and the geophysical mechanisms responsible for it.

This book is intended for geophysicists, astronomers (especially those with an interest in history), historians and orientalists. The culmination of many years of research, it discusses, in depth, ancient and medieval eclipse observations and their importance in studying Earth's past rotation. This was the first major book on this subject to appear in the last twenty years. The author has specialised in the interpretation of early astronomical records and their application to problems in modern astronomy for many years. The book contains an in-depth discussion of numerous eclipse records from Babylon, China, Europe and the Arab lands. Translations of almost every record studied are given. It is shown that although tides play a dominant long-term role in producing variations in Earth's rate of rotation - causing a gradual increase in the length of the day - there are significant, and variable non-tidal changes in opposition to the main trend.

This accessible reference presents the evolution of concepts of time and methods of time keeping, for historians, scientists, engineers, and educators. The second edition has been updated throughout to describe twentieth- and twenty-first-century advances, progress in devices, time and cosmology, the redefinition of SI units, and the future of UTC.

The past few decades have witnessed the growth of the Earth Sciences in the pursuit of knowledge and understanding of the planet that we live on. This development addresses the challenging endeavor to enrich human lives with the bounties of Nature as well as to preserve the planet for the generations to come. Solid Earth Geophysics aspires to define and quantify the internal structure and processes of the Earth in terms of the principles of physics and forms the intrinsic framework, which other allied disciplines utilize for more specific investigations. The first edition of the Encyclopedia of Solid Earth Geophysics was published in 1989 by Van Nostrand Reinhold publishing company. More than two decades later, this new volume, edited by Prof. Harsh K. Gupta, represents a thoroughly revised and expanded reference work. It brings together more than 200 articles covering established and new concepts of Geophysics across the various sub-disciplines such as Gravity, Geodesy, Geomagnetism, Seismology, Seismics, Deep Earth Processes, Plate Tectonics, Thermal Domains, Computational Methods, etc. in a systematic and consistent format and standard. It is an authoritative and current reference source with extraordinary width of scope. It draws its unique strength from the expert contributions of editors and authors across the globe. It is designed to serve as a valuable and cherished source of information for current and future generations of professionals.

NAMED ONE OF THE BEST BOOKS OF THE YEAR BY People ∙ O: The Oprah Magazine ∙ Financial Times ∙ Kansas City Star ∙ BookPage ∙ Kirkus Reviews ∙ Publishers Weekly ∙ Booklist NEW YORK TIMES BESTSELLER “A stunner.”—Justin Cronin “It’s never the disasters you see coming that finally come to pass—it’s the ones you don’t expect at all,” says Julia, in this spellbinding novel of catastrophe and survival by a superb new writer. Luminous, suspenseful, unforgettable, The Age of Miracles tells the haunting and beautiful story of Julia and her family as they struggle to live in a time of extraordinary change. On an ordinary Saturday in a California suburb, Julia awakes to discover that something has happened to the rotation of the earth. The days and nights are growing longer and longer; gravity is affected; the birds, the tides, human behavior, and cosmic rhythms are thrown into disarray. In a world that seems filled with danger and loss, Julia also must face surprising developments in herself, and in her personal world—divisions widening between her parents, strange behavior by her friends, the pain and vulnerability of first love, a growing sense of isolation, and a surprising, rebellious new strength. With crystalline prose and the indelible magic of a born storyteller, Karen Thompson Walker gives us a breathtaking portrait of people finding ways to go on in an ever-evolving world. “Gripping drama . . . flawlessly written; it could be the most assured debut by an American writer since Jennifer Egan’s Emerald City.”—The Denver Post “Pure magnificence.”—Nathan Englander “Provides solace with its wisdom, compassion, and elegance.”—Curtis Sittenfeld “Riveting, heartbreaking, profoundly moving.”—Kirkus Reviews (starred review) Look for special features inside. Join the Circle for author chats and more.

This book describes how changes in the Earth's orientation are observed and computed in terms of tidal forcing and models of the Earth's interior.