This book aims then to describe in a comprehensible way efforts made over centuries of measuring and understanding the magnetic declination. The book also highlights some important characteristics of the Earth's magnetic field thanks to the declination measurements. Some applications and societal implications are also underlined.

Anyone living in the 21st century knows the best way to navigate is by using a smartphone App. Decades and centuries ago, in order to find the same way a magnificent instrument was used: the compass. Despite many being aware of the compass, not everyone appreciates that throughout the ages of exploration, sailors and explorers linked their lives and great discoveries to the magnetic needle. Furthermore, is there an awareness of the Earth's physical mechanism behind the changes in time and space of the direction indicated by the compass? The magnetic declination is at the center of this book and it helps the reader to understand how to navigate in time and space. The book provides the history of the compass and magnetic declination leading the reader to the understanding of our magnetic planet.

This book is designed for those who are fascinated by the long history of geomagnetism. This book relies on reader's knowledge of elementary scientific concepts, and introduces the geomagnetism concepts as they evaluated in time. The focus is on some basic concepts and physical processes in order to understand the evolution of a specific element of the geomagnetic field, the declination. The primary audience may have just started an interest in the geomagnetism and history of science, as students and researchers. Some readers may have an interest that only touches the geomagnetism, as navigators, geophysicists, historians.

Situated at the intersection of science and history A special section dedicated to ancient magnetic declination data Addresses key characteristics of the Earth's magnetic field

Autorentext
Mioara Mandea is currently the Head ' Science Coordination ' Department Strategy Directorate at Centre National d'Etudes Spatiales in Paris (French Space Agency). Over recent decades, she has been involved in many activities of the International Association of Geomagnetism and Aeronomy (both Secretary General and President), European Geosciences Union (General Secretary and Chair of Outreach Committee), American Geophysical Union (Chair of Education Award Committee), International Space Science Institute (Chair of Science Committee), Commission for the Geological Map of the World (President of the Sub-commission of Geophysical maps), to name the most important. Mioara Mandea has published some176 peer-reviewed publications, 22 books and chapters in books, with important contributions to Encyclopedia and Treatises, proceedings and reports (70) and has been involved in organising many workshops and conferences. She has also led several multi-partner research projects or work packages within projects at different national and EU levels, as the prestigiuos ERC Synergy Grant for the project "GRACEFUL". She has tutored PhD students from many countries around the world. She is a member of the Editorial Board of Surveys in Geophysics (from 2009) and of Solid Earth (from 2010) and co-Editor of several books (Springer, CUP). She has acted as reviewer for more than 120 manuscripts submitted to a broad range of journals and as referee for projects submitted to the European Research Council and to the National Science Foundations of France, Romania, Norway, Switzerland, Lithuania, Russia, USA and Portugal. Mioara Mandea is a member of the Academy of Romanian Scientists, Academia Europea, Académie Royale de Belgique, the Russian Academy of Science, Bureau des Lonfitudes, European Academy of Sciences. She received the International Award of American Geophysical Union, the Petrus Peregrinus medal of European Geosciences Union, the Emil Wiechert Medal, Deutsche Geophysikalische Gesellschaft (Germany), the prestigious "Ordre National de Mérite" (France), and Citoyenne d'Honneur de Comanesti (Roumanie).

Inhalt
Some introductory notions.- The poetry and philosophy of the beginnings.- The first attempts of observing the magnetic declination.- Ancient declination maps.- Long-series of declination observations.- Geomagnetic vector field: from ground to satellite measurements.- Magnetic information frozen in the archeological vestiges and rocks.- Maps of magnetic declination over the last centuries.- Spatial evolution: Westward drift.- Temporal evolution: geomagnetic jerks.- Geomagnetic and magnetic poles.- Next interest in magnetic declination.