Reversals of the Earth's Magnetic Field

by J.A. Jacobs

This book deals with the particular case of reversals of the Earth's magnetic field. These have played a major role in the development of plate tectonics and in establishing a geological time scale. The magnetism of rocks is discussed in some detail with a warning of possible misinterpretations of the record. The latest observational results and theories are reviewed with special attention to the structure and geometry of the transition field. Changing conditions at the core-mantle boundary, their effect on reversals, the generation of plumes and the possible correlation of reversals with tectonic changes, ice ages or mass extinctions are thoroughly discussed, including suggested periodicities in the reversal record and in other geophysical data.

Genres: Science

358 pages, Hardcover

First published May 1, 1984

Reviews

[C Jon Tice · Rating 4 out of 5]

Very detailed analysis with formulas and data that overwhelmed at times. Reading the intro and conclusion of each section tidied it up so i skipped some of the extraneous information because it mainly reiterated the source data which was largely contradictory. The research was very well documented and i felt Jacob's observations were well warranted after the impressive bibliographical effort.

[Fred Kohn · Rating 4 out of 5]

This books deserves a chapter-by-chapter review that I don't have the expertise to write. First, make sure you read The Magnetic Field of the Earth (recommended by the author of this book) or some similar text. It has been some time since I read that book, so I found myself a bit lost when confronted with various geodynamo models that were not explained. Chapters 1 (The Earth's Magnetic Field) and 5 (Models For Reversals) are the most math intensive, but you can get a lot out of the other chapters even if you ignore these. As a non-specialist, I enjoyed Chapter 8 the most, which covered the more speculative hypotheses for geomagnetic reversals. These included occassional near passages of the hypothetical planet Nemesis (no, he doesn't spend much time on this one!) I do intend to reread this book, but before I do, I plan to read Paleomagnetism (recommended by the author) and reread the Merrill and McElhinney text (taking careful notes this time!)

["The Jo" · Rating 4 out of 5]

A great technical and detailed account of the contrasting theories on the reversals of the earth's magnetic field. If math is not your strong point, I suggest you read this with another book geared towards the general reader to supplement your understanding.